hp-pn8510-5a_network analysis specifying calibration standards

8/14/2019 HP-PN8510-5A_Network Analysis Specifying Calibration Standards

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Netw ork Analysis

Spe cifying cal ibrationstan dards for the HP 8510ne tw ork analyzer

Product Note 8510-5A


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Table of Conten ts

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Mea su re men t Er rors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3Measu rem ent Calibr at ion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Ca libr at ion Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Sta nda rd Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Cla ss Ass ignm en t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Modi fica tio n P roc ed ure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Select St an da rd s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Define S ta nd ar ds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

St an da rd Nu mb er . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

St an da rd Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

C0, Cl, C2 an d C3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

Short Circuit Indu ctan ce Lo Ll, L2 an d L3 . . . . . . . . . . . . . . . . . . . . . . . . . .11

Fixe d or S lidin g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

Term ina l Im peda nce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12Offset Dela y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

Offset Z0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

Offset Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

Lower /Minim um Fr equ ency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

Upper/Maximum Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Coax or Wavegui de . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Sta nda rd L abels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Assign Cla sse s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Sta nda rd Cla sses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Sll

A,B,C an d S22

A,B,C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

Forwa rd Tra nsm ission Mat ch/Thru . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

Reverse Tran smiss ion Mat ch/Thru . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

Isola tion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Fr equ en cy Respon se . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

TRL T hr u . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

TRL R eflect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

TRL L ine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Adap te r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

St an da rd C las s La bels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

TRL O pt ions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Ca libr at ion Kit La bel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

En ter Sta nda rds /Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Veri fy Per forma nce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

User Modified Cal Kits and HP 8510A Specifications . . . . . . . . . . . . . . . .22

Modification Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

Modelin g a Th ru Adap te r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

Modeling an Arbitr ar y Imp edan ce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

Appendix A

Calibr at ion Kit En tr y Procedur e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

Appendix B

Dimen sional Consider at ions In Coaxia l Connectors . . . . . . . . . . . . . . . . . . . . . .27

2

Known devices called calibration

standar ds provide the measurement

reference for network an alyzer error-

corr ection. This not e covers m eth ods for

specifying these standards and

describes the procedures for t heir u se

with th e HP 8510 network ana lyzer.

The HP 8510 network ana lyzer system

has the capability to make real-time

error-corrected measur ement s of

components and devices in a variety of

transmission media. Fundamentally, all

tha t is required is a set of known

devices (standa rds) tha t can be defined

physically or electrically and u sed to

provide a reference for the physical

interface of the test devices.

Hewlett-Packar d supplies fullcalibration kits in 7mm, 3.5mm an d

Type-N coaxial interfaces. The HP 8510

system can be calibrated in other

interfaces such as other coaxial types,

waveguide and microstrip, given good

quality standards t hat can be defined.

The HP 8510s bu ilt-in flexibility for

calibration kit definition allows th e user

to derive a precise set of definitions for a

particular set of calibration standards

from precise physical mea surem ents.

For example, the characteristic

impedance of a ma tched impedan ce

airline can be defined from its actu alphysical dimensions (diameter of outer

and in ner conductors) and electrical

chara cteristics (skin depth). Although

the airline is designed to provide perfect

signal tra nsmission at t he connection

interface, the dimensions of individual

airlines will vary somewha t-resulting in

some reflection due t o the chan ge in

impedance between t he test port a nd

the a irline. By defining the a ctual

impedance of the air line, the resu ltan t

reflection is chara cterized and can be

removed th rough measurement

calibration.

The scope of this product note includes a

general description of the capabilities of

the H P 8510 to accept new cal kit

descriptions via the MODIFY CAL KIT

function found in t he H P 8510 CAL

menu. It does not, however, describe

how to design a set of physical

sta ndar ds. The selection and fabrication

of appropriat e calibrat ion sta ndar ds is

as varied as t he tra nsmission media of

the pa rticular a pplicat ion an d is beyond

the scope of this note.


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This product note covers measu remen t calibration requiremen ts for

th e HP 8510B n etwork a na lyzer. All of th e capa bilities described in

th is note also apply to the H P 8510A with th e following exceptions:

Response & Isolat ion calibra tion; Short circuit indu ctan ce; classassignments for forward/reverse isolation, TRL Thru, Reflect, Line

an d Options; and Adapt er Removal.

Measureme nt Errors

Measur ement err ors in network an alysis can be separa ted into two

categories: ran dom and systema tic errors. Both r an dom and

systemat ic errors ar e vector quan tities. Ran dom errors are n on-

repeatable measurement variations a nd are usually unpredictable.

Systematic errors are r epeatable measur ement variations in the t est

setup.

Systemat ic errors include misma tch an d leakage signa ls in th e test

setup, isolation cha ra cteristics between th e reference and test signa lpat hs, an d system frequency response. In most microwave

measu remen ts, systemat ic errors a re th e most significan t source of

measu remen t u ncertaint y. The sour ce of th ese errors can be

at tribut ed to the signal separat ion scheme used.

The systematic errors present in an S-param eter measurement can

be modeled with a signa l flowgra ph. Th e flowgra ph m odel, which is

used for er ror corr ection in t he H P 8510 for t he er rors a ssociated

with mea sur ing the S -par am eters of a two port device, is shown in

th e figure below.

The six systemat ic errors in the forward direction

ar e directivity, sour ce ma tch, reflection tr acking,

load ma tch, tran smission tr acking and isolation.

The r everse error m odel is a m irror image, giving

a t otal of 12 err ors for t wo-port measu remen ts.

The pr ocess of removing these systemat ic errors

from the network ana lyzer S-par amet er

measurement is called measurement calibration.

E DF , E DR-Directivity E LF, E LR-Load Ma tch

E SF , E SR-Source Match E TF, E TR-

Trans. Tracking

E RF , E RR-Refl. Tracking E XF, E XR-Isolation

Measureme nt Calibration

A more complet e definit ion of mea sur emen t

calibration using t he HP 8510, an d a description of

the er ror models is included in t he HP 8510

operating an d programming man ual. The basic

ideas a re summ arized here.

A measur ement calibrat ion is a pr ocess which

mat hema tically derives th e error model for the

HP 8510. This err or model is a n a rr ay of vector

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Introduct ion

Figure 1. HP 8510 Full 2-Port E rror Model


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coefficients used to esta blish a fixed reference plan e of zero pha se

shift, zero magnitu de an d kn own impedance. The ar ray coefficients

ar e comput ed by measu rin g a set of kn own devices conn ected at a

fixed point an d solving as t he vector difference between t he m odeledand measured response.

The full 2-port err or model shown in figure 1 is an exam ple of only

one of th e measu remen t calibrat ions a vailable with t he HP 8510.

The measu remen t calibrat ion process for the HP 8510 must be one

of seven t ypes; RESP ONSE , RESPON SE & ISOLATION, S ll 1-

PO RT, S 22 1-PORT, ONE PATH 2-PORT, FU LL 2-PORT, an d TRL 2-

PORT. Ea ch of th ese calibrat ion t ypes solves for a differen t set of th e

systemat ic measu rement errors. A RESPONSE calibration solves

for t he system atic error ter m for r eflection or t ran smission t racking

depending on th e S-par am eter which is activated on the HP 8510 at

the time. RESPONSE & ISOLATION adds correction for crosstalk

to a simple RESP ONSE calibration. An S 11 l-PORT calibrat ion solvesfor the forward error terms, directivity, source match and reflection

tr acking. Likewise, the S 22 1-PORT calibra tion solves for t he sa me

error t erms in th e reverse direction. A ONE PATH 2-PORT

calibrat ion solves for a ll the forwar d err or term s. FULL 2-PORT and

TRL 2-PORT calibrat ions include both forward an d r everse error

terms.

The type of measu remen t calibra tion selected by the u ser depends

on th e device to be meas ur ed (ie. 1-port or 2-port device) an d th e

extent of accuracy enhan cement desired. Furt her, a combinat ion of

calibrat ions can be u sed in th e measu remen t of a pa rticular device.

The accur acy of subsequent t est device measu remen ts is dependent

on th e accura cy of th e test equipm ent , how well the known devices

ar e modeled an d th e exactness of the err or corr ection model.

Calibration Kit

A calibrat ion k it is a set of ph ysical devices called stan da rds . Each

sta nda rd ha s a precisely known or predicta ble magn itude and ph ase

resp onse as a fun ction of frequen cy. In order for th e HP 8510 t o use

th e stan dar ds of a calibrat ion kit, the r esponse of each stan dar d

mu st be math emat ically defined and th en organ ized into sta nda rd

classes which corr espond t o the err or models used by t he HP 8510.

HP current ly supplies calibra tion kits with 7mm (HP 85050B/C/D),3.5mm (HP 85052B/D) and N -type (HP 85054B) coaxial conn ectors.

To be able to use a par ticular calibration kit, th e known

char acteristics from each sta ndard in the kit must be entered into

th e HP 8510 nonvolatile memory. The operating a nd service

ma nu als for each of th e HP calibration kits conta in th e physical

char acteristics for each standa rd in the k it and math ematical

definitions in t he forma t r equired by the HP 8510.

Waveguide calibration using t he H P 8510 is possible alth ough HP

does not pr esently supply the waveguide standa rds for a ll frequen cy

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bands . Calibrat ion in microstrip an d other non-coaxial m edia is

described in H P Pr oduct Note 8510-8.

Standard Definit ion

Sta nda rd Definition is the pr ocess of ma them atically modeling the

electrical characteristics (delay, attenuation and impedance) of each

calibrat ion st an dar d. These electr ical char acteristics can be

ma them atically derived from the ph ysical dimensions an d ma terial

of each calibrat ion st an dar ds or from its actua l measur ed response.

A Standa rd Definition table (see Table 1) lists t he pa ra meters th at

ar e used by the H P 8510 to specify the m ath emat ical model.

Class Assignmen tClass assignmen t is th e process of organizing calibrat ion st an dar ds

into a forma t wh ich is compa tible with t he err or models used in

measurement calibration. A class or group of classes correspond to

th e seven calibration types used in t he HP 8510. The 17 available

classes are identified later in t his n ote (see Assign Classes).

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6

Table 1. Standard Definitions Table

Table 2. Stand ard Class Assign men ts

STANDARD CLASS ASSIGNMENTS

1.Forward Isolation Standard is also used for Isolation of Response and Isolation calibration.


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Calibration kit modificat ion provides th e capability t o adapt to

measu remen t calibrat ions in other conn ector types or to generat e

more precise error models from existing kits. Provided the

appr opriate sta nda rds a re ava ilable, cal kit modificat ion can be u sedto establish a r eference plan e in the same tr an smission media as t he

test devices an d at a specified point , gener ally the point of device

conn ection/insertion. After calibrat ion, th e resulta nt measu remen t

system, including a ny ada pters which would reduce system

directivity, is fully corrected a nd th e systema tic measur ement errors

ar e ma th ema tically removed. Additiona lly, the modification function

allows th e user to input more precise physical definitions for the

sta nda rds in a given cal kit. The process to modify or create a cal kit

consist s of the following st eps:

1. Select sta nda rds

2. Define stan dar ds

3. Assign class es

4. Enter standards/classes5. Verify performance

To fur th er illustra te, an example waveguide calibration kit is

developed as t he gener al descript ions in MODIF Y CAL KIT process

are presented.

Select Standards

Determine what st an dar ds are necessary for calibration and ar e

available in the t ra nsmission media of the test d evices.

Calibration stan dar ds ar e chosen based on the following criteria:

A well defined r esponse which is mechan ically repeatable an d

sta ble over typical am bient temper atu res an d conditions. The most

common coaxial standards are zero-electrical-length short, shielded

open a nd m at ched load term inations which ideally have fixed

ma gnitude an d broadband ph ase response. Since waveguide open

circuits a re genera lly not m odelable, th e types of standa rds typically

used for waveguide calibrat ion a re a pa ir of offset short s an d a fixed

or sliding load .

An independent frequen cy response. To fully calibrate each test

port (that is to provide the stan dar ds necessary for S 11 or S22 1-PORT

calibrat ion), th ree stan dar ds are required tha t exhibit distinct phase

an d/or magn itude at each par ticular frequency within thecalibrat ion ba nd. F or example, in coax, a zero-length short an d a

perfect sh ielded open exhibit 180 degree ph ase sepa ra tion while a

ma tched load will provide 40 to 50 dB ma gnitude sepa ra tion from

both th e short a nd t he open. In waveguide, a pair of offset sh orts of

correct length provide pha se separ ation.

Broadband frequency coverage. In broadban d app lications, it is

often difficult t o find sta nda rds t ha t exhibit a known, suitable

response over t he ent ire ban d. A set of frequen cy-band ed sta nda rds

of th e sam e type can be selected in order to cha racterize the full

measurement band.

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Modif icat ion P rocedu re


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The TRL 2-PORT calibrat ion requ ires only a single precision

impedance standa rda t ran smission line. An un known high

reflection device an d a t hr u conn ection a re su fficient t o complet e

this technique.

Define Standards

A glossar y of sta nda rd definition para meter s used with th e

HP 8510 is included in th is section. Each par amet er is described

an d appr opriate conversions a re listed for implement at ion with t he

HP 8510. To illustrate, a calibration kit for WR-62 rectangular

waveguide (operat ing frequen cy ra nge 12.4 to 18.0 G Hz) will be

defined a s sh own in Table 1. Subsequent sections will cont inue t o

develop this waveguide example.

Figure 2. Standard Definition Models

8

Model for Reflection Stan dard

(short, open, load or arbitraryImpedance)

Model for Transm ission Sta ndard(Thru)


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The ma th emat ical models ar e developed for each st an dar d in

accorda nce with t he sta nda rd definition para meter s provided by

th e HP 8510. These stan dar d definition par am eters ar e shown in

Figure 2.

Ea ch stan dar d is described using the Sta nda rd Definition Table in

accorda nce with t he 1 or 2 port m odel. The Stan dar d Definition

ta ble for a waveguide calibra tion kit is sh own in Table 1. Each

sta nda rd type (short, open, load, thr u an d arbitr ary impedan ce) ma y

be defined by th e par am eter s as specified below.

Standard number and standard type

Fr inging capa cita nce of an open, or indu ctance of a short, specified

by a th ird order polynomial

Load/arbit ra ry impeda nce, which is specified as fixed or sliding

Termina l resistan ce of an a rbitra ry impedance

Offsets which a re sp ecified by delay, Z0, R loss Frequency range

Connector type: coaxial or waveguide

Label (up t o 10 alphan umeric char acters)

Standard Number

A calibration kit m ay cont ain u p to 21 sta nda rds (See Table 1). The

required n um ber of standa rds will depend on frequency coverage

an d whether t hru ada pters a re needed for sexed connectors.

For t he WR-62 waveguide exam ple, four st an dar ds will be sufficient

to perform th e FULL 2-PORT calibrat ion. Thr ee reflection

standa rds ar e required, and one tra nsmission sta ndard (a t hru) will

be sufficient to complete th is calibra tion kit.

Standard Type

A stan dar d type m ust be class ified as a short open, load th ru

or ar bitra ry imp edan ce. The a ssociated models for r eflection

sta nda rds (short , open, load and ar bitrar y impedan ce) an d

tran smission sta ndards (thr u) are shown in F igure 1.

For th e WR-62 waveguide calibrat ion kit, th e 4 stan dar ds ar e a

1/8 & 3/8 offset short, a fixed mat ched load and a thr u. Stan dar dtypes are entered into the Stan dar d Definition ta ble un der

STANDARD NUMBERS 1 thr ough 4 a s short, short, load a nd t hru

respectively.

Open Circuit Capacita nce: C0 , C 1 , C 2 and C3

If the st an dar d type selected is an open, the C0 through C3coefficients ar e specified an d t hen used to ma them atically model th e

pha se shift caused by fringing capa citan ce as a function of

frequency.

As a reflection sta nd ar d, an open offers th e adva nt age of broadba nd

frequen cy covera ge, while offset short s cann ot be used over more

th an an octa ve. The reflection coefficient ( = pe-je) of a per fect zer o-

9


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length -open is 1 at 0 for a ll frequ encies. At m icrowave frequen cies

however, th e magn itu de an d ph ase of an opens ar e affected by the

ra diat ion loss a nd capacitive fringing fields, respectively. In

coaxial transmission media, shielding techniques are effective inreducing the ra diation loss. The magnitud e (p) of an open is

ass igned to be 1 (zero radia tion loss) for all frequ encies when u sing

th e HP 8510 St an dar d Type open.

It is n ot possible to remove fringing capa cita nce, but the resulta nt

pha se shift can be m odeled as a fun ction of frequency using C 0thr ough C3 (C0 +C l x F + C2 x F

2 + C 3 x F3,with u nit s of F(Hz), C0(fF),

C1(10-27F/H z), C2(10

-36F/Hz2) an d C3(10-45F/Hz3), which a re t he

coefficients for a cubic polynomia l tha t best fits t he a ctua l

capa citance of the open.

A number of meth ods can be used to determin e the fringing

capacita nce of an open. Three t echniqu es, described her e, involve acalibrat ed reflection coefficient measu remen t of an open sta nda rd

and subsequent calculation of the effective capacitance. The value of

fringing capacitance can be calculated from t he mea sur ed pha se or

rea ctan ce as a function of frequen cy as follows.

Ceff effective capa cita nce

measur ed phase shiftf measur ement frequency

Z0 chara cteristic impedance

X measu red rea ctance

This capa cita nce can t hen be modeled by choosing coefficient s to

best fit the meas ured r esponse when mea sur ed by either met hod 3

or 4 below.

1. Fully calibrated 1-PortE sta blish a calibrat ed reference plan e

using th ree independent sta nda rds (tha t is, 2 sets of banded offset

shorts a nd load). Measu re th e pha se response of the open a nd solve

for the capacitance function.

2. TRL 2-PORTWhen tra nsm ission lines stan dar ds are a vailable,

th is meth od can be used for a complete 2-port calibrat ion. With

error-correction applied th e capacitance of th e open can be mea sured

directly.

3. Gat ingUse time doma in gating to correct th e measu red response

of th e open by isolat ing th e reflection due t o the open from the

source mat ch reflection an d signal pat h leakage (directivity).

Figure 3 sh ows th e time domain response of th e open at th e end of

an a irline. Measu re th e gated phase response of th e open at t he end

of an airline an d a gain solve for t he capacitance function.

10

tan( )

2

2fZ0

1

2fXCeff= =


11/30

Figure 3. Time domain respon se of open at the en d of an air l ine

Note

In some cases (when t he pha se response is linear with respect to

frequency) the r esponse of an open can be modeled as an equivalent

incremen ta l length .

This met hod will serve as a first order appr oximat ion only, but can

be useful when d ata or stan dar ds for t he above modeling techniques

ar e not available.

For th e waveguide example, this pa ram eter is not addressed since

opens cann ot be made valid stan dar ds in waveguide, due to the

excessive radiat ion loss and indeterm inan t pha se.

Short Circuit Inductan ce L0 , L l , L 2 and L3If the st an dar d type selected is a short , th e L0 thr ough L3coefficients ar e specified to model the ph ase s hift caused by th esta nda rds residu al indu ctan ce as a fun ction of frequen cy. The

reflection coefficient of an ideal zero-lengt h s hort is 1 at 180 at a ll

frequen cies. At m icrowave frequen cies, however, the r esidua l

inductan ce can produce additiona l phase sh ift. When th e inductan ce

is known an d repea table, this ph ase sh ift can be accounted for

dur ing the calibration.

11

2f (length)c

(radians) =


12/30

The ind ucta nce as a fun ction of frequen cy can be modeled by

specifying t he coefficient s of a th ird-order polynomia l (L0 + L 1 X F +

L2 X F 2 + L 3 X F3, with u nit s of F(Hz), L0(nH), L1(10

-24H/Hz),

L2(10 -33 H/Hz2) an d L3(10 -42H/Hz3).

For t he wa veguide example, the inductan ce of the offset sh ort

circuits is n egligible. L0 thr ough L3 ar e set equal to zero.

Fixed or Sl iding

If the sta nda rd t ype is specified to be a load or a n a rbitra ry

impeda nce, then it mu st be sp ecified as fixed or sliding. Selection of

sliding provides a su b-menu in th e calibrat ion sequ ence for

mu ltiple slide positions a nd m easur ement . This enables calculation

of th e directivity vector by ma them atically elimina ting th e response

due t o a non-ideal term inal impedan ce. A fur th er explana tion of this

technique is found in th e Measurem ent Ca librat ion section in th e

HP 8510 Operating an d Programming manua l.

The load stan dar d #4 in t he WR-62 waveguide calibration kit is

defined as a fixed load. En ter FIXED in th e ta ble.

Terminal Impeda nce

Term ina l impedan ce is only specified for ar bitr ar y impedan ce

sta nda rds. This a llows definition of only the rea l par t of the

term inat ing impedan ce in ohms . Selection as t he sta nda rd type

short , open or load au toma tically ass igns th e t erm ina l imped an ce

to be 0, or 50 ohm s r espectively.

The WR-62 waveguide calibrat ion kit exam ple does n ot cont ain an

arbitrary impedance standa rd.

Offset Delay

If the sta nda rd h as electrical length (relative to the calibrat ion

plan e), a st an da rd is specified to ha ve an offset delay. Offset delay is

enter ed as th e one-way travel time thr ough an offset th at can be

obtain ed from the ph ysical length usin g propaga tion velocity of light

in free space and th e appropriat e permittivity constan t. The

effective propaga tion velocity equ als cr. See Appendix B for afurt her description of physical offset length s for sexed connector

types.

Delay (seconds) =

= precise measu remen t of offset length in met ers

r = relative permitt ivity(= 1.000649 for coaxial a irline or air-filled waveguide in st an dar d

lab condit ions)

c = 2.997925 X 10 8 m/s

In coaxial transmission line, group delay is constant over frequency.

In wa veguide however, group velocity does vary with frequen cy due

to disper sion as a fun ction of th e cut-off frequ ency.

12

r

c


13/30


14/30

r = relative permea bility constan t of the m edium (equal t o 1.0 inair)

r = relative permitt ivity const an t of the m edium (equal to 1.000649in air)

D = inside dia met er of outer condu ctor

d = out side diameter of inner condu ctor

The HP 8510 requires tha t th e cha racteristic impedan ce of

waveguide tran smission line is assigned to be equal to th e SET Z0.

The chara cteristic impedan ce of oth er tr an smission m edia is not aseasily determined th rough m echa nical dimensions. Waveguide

impeda nce, for examp le, var ies as a function of frequen cy. In su ch

cases, norma lized impedance measur ement s ar e typically made.

When calibrat ing in wa veguide, the im peda nce of a ma tched load is

used a s th e impedan ce reference. The impedan ce of th is load is

ma tched th at of th e waveguide across frequen cy. Normalized

impedance is achieved by entering SE T Z0 and OFFSET Z0 to 1 ohm

for each standard.

Offset Z0 equal to system Z0 (SET Z0) is the a ssigned convention in

th e HP 8510 for m atched waveguide impedance.

Offset LossOffset loss is used t o model th e ma gnitu de loss due to skin effect of

offset coaxial t ype sta nda rds only. The value of loss is enter ed int o

th e sta nda rd definition ta ble as gigohm s/second or ohms/nan osecond

at 1 GHz.

The offset loss in gigohms/second can be calculat ed from th e

measu red loss at 1 GHz an d the ph ysical length of th e part icular

sta nda rd by the following equat ion.

where:dB lOSS | 1GHZ =measured insertion loss at 1 GHZ

Z0 = offset Z0l = physical lengt h of th e offset

The H P 8510 calculates th e skin loss as a fun ction of frequen cy as

follows:

Offset Loss XG

s 1GHzf(GHz)Offset Loss

Gs

=

Offset Loss =G

s 10 log10(e)1GHz

dBloss 1GHzc r Z0

14

Z0 = In = 59.9585 In12

(D)d

r r (D)d


15/30

For all offset st an dar ds, including shorts or opens, enter th e one

way skin loss. The offset loss in wa veguide should a lways be

assigned zero ohm s by the HP 8510.

Ther efore, for t he WR-62 waveguide st an dar d definit ion t able, offset

loss of zero ohm /sec is ent ered for all four st an dar ds.

Lower/Minimum Frequency

Lower frequency defines t he m inimum frequency at which t he

sta nda rd is to be used for th e purposes of calibrat ion.

Note

When defining coaxial offset st an dar ds, it ma y be necessary to use

ban ded offset short s to specify a sin gle stan dar d class . The lower

an d upper frequency par am eters should be used to indicat e the

frequency range of desired response. It sh ould be noted th at loweran d upper frequency serve a du al purp ose of separa ting banded

sta nda rds wh ich compr ise a single class as well as defining th e

overall app licable frequency ran ge over which a calibrat ion kit m ay

be used.

In wa veguide, this m ust be its lower cut -off frequen cy of th e

prin cipa l mode of propa gat ion. Waveguide cut off frequ encies can be

foun d in m ost waveguide t extbooks. The cut off frequ ency of the

fundam enta l mode of propagat ion (TE 10) in r ecta ngular waveguide is

defined as follows.

f = c

2a

c = 2.997925 X 1010 cm/sec.

a = inside width of waveguide, lar ger dimen sion in cm

As referen ced in offset delay, the m inimu m frequen cy is used t o

compute the dispersion effects in waveguide.

For t he WR-62 waveguide examp le, the lower cut off frequ ency is

calcula ted as follows.

f = c = 2.997925 X 1010 cm/s = 9.487 GHz

2a 2 X 1.58 cm

c = 2.997925 X 1010 cm/sa = 1.58 cm

The lower cut-off frequ ency of 9.487 GHz is ent ered in to th e ta ble for

all four WR-62 waveguide stan dar ds.

15


16/30

Upper/Maximum Frequency

This specifies the maximum frequency at wh ich th e stan dar d is

valid. in broadban d applicat ions, a set of banded st an dar ds ma y be

necessa ry to provide consta nt resp onse. For examp le, coaxial offsetsta nda rds (ie. 1/4 offset sh ort) ar e gener ally specified overban dwidth s of an octa ve or less. Ban dwidth specificat ion of

sta nda rds, using minimum frequency and maximu m frequency,

enables th e HP 8510 to cha racterize only the specified band du ring

calibrat ion. Fur ther, a submenu for band ed standa rds is ena bled

which r equires th e user t o completely cha ra cterize the curr ent

measu remen t frequency ra nge. In waveguide, this is the upper

cutoff frequen cy for t he wa veguide clas s an d mode of propa gat ion.

For th e fun dam enta l mode of propagation in rectangular waveguide

th e ma ximum upp er cutoff frequen cy is twice th e lower cutoff

frequen cy an d can be calculat ed as follows.

F(upper) = 2 X F(lower)

The u pper frequency of a waveguide stan dar d m ay a lso be specified

as t he ma ximum operat ing frequency as listed in a textbook.

The MAXIMUM F REQUE NCY of the WR-62 waveguide cal kit is

18.974 GHz and is ent ered into the st an dar d definition t able for all

four standa rds.

Coax or Wave guide

It is n ecessary t o specify wheth er t he st an dar d selected is coaxial or

waveguide. Coaxial tra nsmission line ha s a linear pha se response as

Waveguide tra nsm ission line exhibits dispersive pha se response a s

follows.

where

Selection of WAVEGUIDE compu tes offset dela y u sing t he

disper sive response, of recta ngu lar wa veguide only, as a function of

frequency as

This empha sizes th e importa nce of ent ering fco as t he LOWE R

FRE QUEN CY.

1-(fco/f)2Delay (seconds) Linear Delay=

1-(/co)2g

=

2(radians)

g=

2 2f(delay)(radians)

==

16


17/30

Selection of COAXIAL ass um es linea r resp onse of offset dela y.

Note

Mathematical operations on measurements (and displayed data)after calibration a re n ot corrected for dispersion.

En ter WAVEGUIDE into th e sta nda rd definition table for all four

standards.

Standa rd Labels

Labels ar e entered thr ough th e ti t le menu an d may conta in up t o 10

chara cters. Sta nda rd Labels are enter ed to facilitat e menu dr iven

calibrat ion. Labels that describe and different iate each sta nda rd

should be used. This is especially tru e for m ultiple stan dar ds of th e

same t ype.

When sexed connector standards are labeled, male (M) or female (F),th e designa tion refers t o the test port conn ector sexnot t he

conn ector sex of th e stan dar d. Furt her, it is recommended th at t he

label include inform ation car ried on th e stan dar d such as th e serial

nu mber of the pa rticular st an dar d to avoid confusing multiple

standa rds which a re similar in appearan ce.

The labels for the four stan dar ds in th e waveguide example are;

#1-PSHORT1, #2-PSHORT2, #3-PLOAD, and #4-THRU.

Assign ClassesIn t he pr evious section, Define St an dar ds, the char acteristics of

calibrat ion st an dar ds were derived. Class assignment organ izes

th ese stan dar ds for compu tat ion of the var ious err or models used incalibrat ion. The HP 8510 requires a fixed nu mber of sta nda rd

class es to solve for th e n ter ms u sed in th e err or models (n = 1, 3 or

12). That is, the n um ber of calibration error t erms r equired by the

HP 8510 to cha ra cterize the mea sur ement s ystem (1-Port, 2-Port,

etc.) equals the number of classes utilized.

Standard Classes

A single Stan dar d Class is a sta nda rd or group of (up to 7)

sta nda rds th at compr ise a single calibrat ion step. The standa rds

within a single class ar e assigned to locations A th rough G as listed

on the Class Assignments t able. It is importa nt to note th at a class

mu st be defined over t he ent ire frequency ran ge that a calibration is

made, even th ough several separat e standa rds ma y be required to

cover the full measu remen t frequency ra nge. In th e measur ement

calibrat ion process, the order of stan dar d measu remen t within a

given class is not import an t un less significant frequency overlap

exists am ong the standa rds used. When two standa rds ha ve

overlapping frequency bands, the last st an dar d to be measu red will

be used by th e HP 8510. The order of sta nda rd measu rement

between different classes is n ot restr icted, although t he H P 8510

requires th at a ll sta nda rds th at will be used with in a given class ar e

measu red before proceeding to th e next class. Stan dar ds ar e

organized into specified classes which ar e defined by a Sta nda rds

17


18/30

Class Assignment ta ble. See Table 2 for the class assignmen ts t able

for the waveguide calibration kit.

S 11 A,B,C and S 22 A,B,C:S 11 A, B,C and S22 A,B,C correspond to th e S11 and S 22 reflection

calibrat ions for port 1 an d port 2 res pectively. These th ree classes

ar e used by th e HP 8510 to solve for the syst emat ic errors;

directivity, source match, and reflection tracking. The three classes

us ed by t he 7mm cal kit ar e labe led sh ort , open, an d loads .

Loads refers t o a group of sta nd ar ds wh ich is r equired to complet e

th is stan dar d class. A class ma y include a s et of sta nda rds of which

th ere is more tha n one acceptable selection or m ore th an one

sta nda rd required to calibrate th e desired frequency ra nge.

Table 2 cont ains th e class a ssignment for the WR-62 waveguide cal

kit. Th e 1/8 offset sh ort (stan dar d #1) is assigned to S 11A. The 3/8

offset sh ort (stan dar d #2) is assigned to S 11B. The mat ched load(standa rd #3) is assigned to S11C.

Forward Transm ission Match and Thru

Forward Tra nsm ission (Match a nd Th ru) classes corr espond t o the

forwar d (port 1 to port 2) tran smission a nd r eflection measu rement

of th e delay/thr u stan da rd in a FU LL 2-PORT or ONE-PATH

2-PORT calibration. During measu remen t calibration the r esponse

of th e mat ch sta nda rd is u sed to find th e systemat ic Load Ma tch

error term. Similarly the response of the t hru standa rd is used to

characterize transmission tracking.

The class assignment s for t he WR-62 waveguide cal kit ar e as

follows. The th ru (stan dar d #4) is as signed t o both FORWARDTRANSMISSION an d F ORWARD MATCH.

Reverse Transmission Match an d Thru

Reverse Tran smission (Match a nd Th ru) classes correspond t o the

reverse tr an smission a nd r eflection measu remen t of the delay/thru

standa rd. For S-param eter test sets, this is the port 2 to port 1

tr an smission path . For the reflection/tra nsm ission test sets, the

device is reversed and is measur ed in the sa me man ner u sing the

forwar d tr an smission calibration.

The class assignment s for t he WR-62 waveguide cal kit ar e as

follows. The th ru (Sta nda rd #4) is assigned to both RE VERSE

TRANSMISSION a nd REVERSE MATCH.

Isolation

Isolat ion is simply the leakage from port 1 to port 2 intern al to th e

test set.

To determine th e leaka ge signals (crosstalk), each port sh ould be

term inat ed with m atched loads while measu ring S21 and S 12.

The class assignment s for forwar d an d reverse isolation ar e both

loads (stan dar d #3).

18


19/30

Frequency Response

Fr equen cy Response is a single class wh ich corr esponds t o a one-

term error corr ection tha t char acterizes only the vector frequency

response of the test configuration. Transmission calibration typicallyuses a th ru an d reflection calibrat ion t ypically uses eith er a n open

or a short.

Note

The F requency Response calibration is not a simple frequen cy

norma lizat ion. A normalized response is a m at hema tical comparison

between measur ed data a nd stored data . The import an t difference

is, th at wh en a st an dar d with non-zero phase, such as an offset

short, is remeasu red a fter calibration using Fr equency Response,

th e actua l pha se offset will be displayed, but its norma lized

response would display zero phas e offset (measu red r esponse m inus

stored response).

Therefore, th e WR-62 waveguide calibrat ion kit class assignment

includes standard #1, standard #2 and stan dard #4.

TRL Thru

TRL Thru corr esponds to the m easur ement of th e S-par am eters of a

zero-length or short t hr u conn ection between port 1 a nd port 2. The

Thru , Reflect an d Line classes are used exclusively for th e th ree

step s of th e TRL 2-PORT calibrat ion. Typically, a delay/thr u with

zero (or very sm all) Offset Delay is specified as t he TRL Th ru

standard.

TRL Reflect

TRL Reflect correspond s to th e S11 and S 22 measu remen t of a highlyreflective 1-port d evice. The Reflect (typically an open or s hort

circuit) mu st be t he sa me for port 1 an d 2. The reflection coefficient

ma gnitu de of th e Reflect should be close to 1 but is n ot specified.

The p ha se of th e Reflection coefficient need only be a ppr oxima tely

specified (within +/ - 90 degrees).

TRL Lin e

TRL Line corr esponds t o the measu remen t of th e S-par am eters of a

short t ran smission line. The impedance of this line deter mines th e

reference impeda nce for the subsequent error-corrected

measu remen ts. The insertion pha se of the Line n eed not be precisely

defined but m ay not be th e same a s (nor a mu ltiple of pi) th e pha se

of th e Thru .

Adapter

This class is used t o specify the a dapt ers u sed for the a dapt er

removal process. The stan dar d num ber of th e adapt er or ada pters to

be cha ra cterized is entered int o the class a ssignment. Only an

estim at e of th e ada pter s Offset Delay is requ ired (within +/ - 90

degrees). A simple way to estima te t he Offset Delay of an y ada pter

would be as follows. Per form a 1-port calibra tion (Response or S 111-PORT) an d then conn ect th e adapt er to the test port. Termina te

the a dapter with a short circuit an d th en measur e the Group Delay.

19


20/30

If the sh ort circuit is not a n offset sh ort, the ada pter s Offset Delay

is simply l/2 of the m easu red d elay. If the sh ort circuit is offset, its

delay must be subt ra cted from the m easur ed delay.

Ea ch adapt er is specified as a single delay/thru st an dar d and u p to

seven stan dar ds nu mbers can be specified into the a dapt er class.

Standa rd Class Labels

Sta nda rd Class labels are enter ed to facilitat e menu -driven

calibration. A label can be any user-selected term which best

describes th e device or class of devices th at th e opera tor sh ould

conn ect. Predefined labels exist for ea ch class. Thes e labels ar e

S 11A, S 11B, S 11C, S22A, S 22B, S22C, FWD TRANS, F WD MATCH, RE V

TRANS, REV MATCH, RESP ONSE , FWD ISOLATION, REV

ISOLATION, THRU, REF LECT, LINE an d ADAPTER.

The class labels for the WR-62 waveguide calibration kit ar e asfollows; S llA an d S 22APSHORT1; S llB and S 22BPSHORT2; S llC and

S 22CPLOAD; FWD TRANS, FWD MATCH, REV TRANS an d RE V

MATCHPTHRU; and RESPONSERESPONSE.

TRL Option s

When performin g a TRL 2-PORT calibrat ion, certain options may be

selected. CAL Z is used to specify whet her skin -effect-relat ed

impeda nce varia tion is to be used or n ot. Skin effect in lossy

tr an smission line sta nda rds will cause a frequency-dependent

variat ion in impedance. This variation can be compensa ted when

th e skin loss (offset loss) and t he m echan ically derived impeda nce

(Offset Z0) are sp ecified an d CAL Z0: SYSTEM Z0 selected. CAL Z0:

LINE Z0 specifies tha t t he impedan ce of the line is equal to th eOffset Z0 at all frequencies.

The ph ase r eference can be specified by the Th ru or Reflect du ring

th e TRL 2-PORT calibrat ion. SET REF: THRU corr esponds to a

reference plane set by Thr u st an dar d (or t he ra tio of the physical

lengths of th e Thru a nd Line) and SET REF : REFLE CT corr esponds

to the Reflect sta nda rd.

LOWBAND FRE QUENCY is u sed to select t he m inimum frequency

for coaxial TRL calibra tions. Below th is frequen cy (typically 2 to

3 GHz) S 11 and S 22 1-PORT calibrat ions can be used. Un like

MINIMUM FRE QUENCY, th is frequency may be n eglected du ring

calibrat ion. In th at case th e TRL sta nda rds would be used over th e

full frequ ency ra nge. To achieve specified per form an ce in a coaxial

interface, TRL stan dar ds sh ould only be used down to the low-band

frequen cy. Note: The resu lta nt calibrat ion is a sin gle cal set

combining the TRL and conventional l-PORT calibrations.

Calibration Kit Label

A calibra tion kit la bel is selected t o describe th e conn ector type of

th e devices to be measu red. If a new label is not generat ed, the

calibrat ion k it label for th e kit previously cont ained in th at

calibrat ion k it regist er (CAL 1 or CAL 2) will rem ain . The

20


21/30

predefined labels for t he t wo calibration kit registers a re:

Calibration kit 1 Cal 1 HP 85050B

7mm B.1

Ca libr a tion k it 2 Ca l 2 H P 85052B

3.5mm B. 1

Again , cal kit la bels should be chosen t o best describe the calibra tion

devices. The B.1 default suffix corr esponds to t he kits m echan ical

revision (B) and mathematical revision (1).

Note

To prevent confusion, if any standard definitions in a calibration kit

ar e modified but a new kit label is not ent ered, the default label will

appear with th e last cha racter replaced by a *. This is not the case

if only a class is redefined with out chan ging a sta nda rd d efinition.

The WR-62 waveguide calibra tion kit can be labeled simply

P BAND.

Enter Stan dards/Classes

The specificat ions for t he Sta nda rd Definition table an d Sta nda rd

Class Assignment s table can be ent ered into the HP 8510 through

front p an el menu-driven ent ry or under pr ogram cont rol by an

externa l cont roller. The procedure for entr y of standa rd definitions,

sta nda rd labels, class assignmen ts, class labels and calibration kit

label is described in Appen dix A.

Note

DO NOT exit the calibration kit modification process without saving

th e calibration kit definitions in th e appropriate r egister in t he

HP 8510. Fa ilure to save th e redefined calibration kit will result in

not saving th e new definitions and th e original definitions for tha t

register will rem ain . Once th is process is complet ed, it is

recommen ded tha t th e new calibration kit should be saved on ta pe.

Verify Performanc e

Once a measu remen t calibrat ion using a pa rticular calibrat ion kit

ha s been gener at ed, its perform an ce should be checked before

ma king device measu remen ts. To check th e accur acy that can be

obta ined using t he n ew calibration kit, a device with a well defined

frequency response (preferably unlike any of th e stan dar ds used)should be measur ed. It is importa nt to note tha t th e verification

device must n ot be one of th e calibrat ion st an dar ds. Calibrat ed

measu remen t of one of the calibration stan dar ds is merely a

measu re of repeat ability.

A perform an ce check of waveguide calibra tion kit s is often

accomplished by measur ing a zero length short or a sh ort at t he end

of a straight section of waveguide. The measured response of this

device on a polar display should be a dot at 1 180. The deviationfrom the k nown is an indication of th e accur acy.

21


22/30

To achieve a more complete verification of a particular measurement

calibration, (including dynamic accuracy) accurately known

verificat ion sta nda rds with a diverse magnitu de and ph ase response

should be used. NBS traceable or HP sta nda rds ar e recommended toachieve verifiable measu remen t accur acy. Fu rt her, it is

recommen ded tha t verification sta nda rds with kn own but different

pha se and ma gnitude response tha n an y of the calibra tion

sta nda rds be u sed to verify performa nce of the HP 8510.

As n oted previously, the resulta nt accur acy of the H P 8510 when

used with a ny calibration kit is dependent on how well its sta nda rds

ar e defined an d is verified thr ough measu remen t of a device with

tr aceable frequen cy response.

The pu blished Measu remen t Specifications for t he H P 8510Network Analyzer syst em include calibrat ion with HP calibrat ionkits such as th e HP 85050B. Measur ement calibrations made withuser defined or modified calibration kits ar e not su bject t o the H P8510 performa nce specifications a lthough a procedure similar to th e

sta nda rd verification pr ocedure m ay be used.

Modeling A Thru Adapter

The MODIFY CAL KIT fun ction allows more pr ecise definition of

existing sta nda rds, such as t he th ru. For exam ple, when m easur ing

devices with t he sa me sex coaxial conn ectors, a set of th ru

sta nda rds to ada pt n on-inserta ble devices on each end is needed.

Var ious t echniqu es ar e used t o can cel th e effects of th e th ru

ada pters. H owever, using th e modify cal kit function to mak e aprecise definition of the th ru ' enables th e HP 8510 to mat he-

ma tically remove th e att enua tion and ph ase sh ift du e to the thr u'

ada pter. To model corr ectly a th ru of fixed length , accura te ga uging

(see OFFSET DELAY) and a precise measurement of skin-loss

at tenu at ion (see OFFSE T LOSS) are requ ired. The chara cteristic

impedance of th e th ru can be foun d from th e inner an d outer

condu ctor diameter s a nd th e perm ittivity of the dielectric (see

OFFSET Z0).

Modeling An Arbitrary Impeda nce Standa rd

The arbitr ar y impedan ce sta nda rd allows the user to model th e

actu al resp onse of an y one port pas sive device for u se as a

calibrat ion st an dar d. As previously stat ed, the calibration isma them atically derived by comparing th e measu red response to the

known response which is modeled th rough th e stan dar d definition

ta ble. However, when th e known r esponse of a one-port sta nda rd is

not pu rely reflective (short/open) or per fectly ma tched (load) but th e

response has a fixed real impedan ce, then it can be modeled as a n

ar bitrar y impedance. A load type sta nda rd h as a n a ssigned

term inal impedance equa l to the system Z0. If a given load h as a n

impedance which is oth er tha n th e system Z0, th e load itself will

produ ce a syst ema tic error in solving for t he dir ectivity of th e

measu remen t system dur ing calibration. A portion of the incident

22

Use r Modified Cal Kits and HP 8510 Spe cif ications

Modif icat ion Examp les


23/30

signal will be reflected from th e misma tched load an d su m t ogether

with th e actual leakage between th e reference and test chan nels

within t he m easur ement system. However, since this r eflection is

systemat ic an d predictable (provided th e term inat ing impedance isknown) it m ay be ma them atically removed. The calibra tion can be

improved if th e stan dar ds term inal impedan ce is entered int o the

definition t able as an arbitr ar y impedance rath er th an as a load.

A procedure similar to tha t u sed for m easur ement of open circuit

capacita nce (see meth od #3) could be used t o make a calibrat ed

measurement of the terminal impedance.

Calibration kit specificat ions can be entered into the H P 8510 using

th e HP 8510 tape dr ive, a disc drive conn ected t o the system bus, by

front p an el ent ry or th rough program contr ol by an externa lcontroller.

Disc/Tape Proc edu re

This is an importa nt featu re since th e HP 8510 can int erna lly store

only two calibration kits at one time while mu ltiple calibrat ion k its

can be stored on a single tape or disc.

Below is th e generic procedure t o load or store calibra tion kit s from

an d to th e ta pe drive or disc interface.

To Load Calibration Kits from a Tape or Disc into the HP 8510

1. Insert th e calibration data t ape into the HP 8510 network

an alyzer (or connect compa tible disc drive to system bu s).

2. Pr ess t he DIS C/TAPE k ey; select STORAGE IS : TAPE or DIS C;

th en pr ess t he following CRT-displayed softk eys:

LOAD

CAL KIT 1-2

CAL KIT 1 or CAL KIT 2 (This selection d eter min es which of the

HP 8510 non-volatile registers th at th e calibrat ion k it will be loaded

into.)

FILE #_ or FILE N AME.

3. To verify that the correct calibration kit was loaded into th e

instrument, press the CAL key. If properly loaded, the calibrationkit label will be shown under CAL 1 or CAL 2 on the CRT

display.

To Store Calibration Kits from th e HP 8510 onto a Tape or D isc

1. Insert an initialized calibration data tap e into the HP 8510

network an alyzer or conn ect compa tible disc drive to th e system

bus.

2. Pr ess t he DIS C/TAPE k ey; select STORAGE IS : DISC or TAPE;

th en pr ess th e following CRT displayed softk eys:

STORE

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Appen dix ACalibrat ion Kit Entry P rocedu re


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CAL KIT 1-2

CAL KIT 1 or CAL KIT 2 (This selection d eter min es which of the

HP 8510 non-volatile calibrat ion kit r egisters is to be st ored.)

FILE #_ or FILE N AME.

3. Examine Directory to verify th at file has been stored. This

completes th e sequence to store a calibra tion k it onto the t ape or

disc.

To gener at e a new cal kit or modify an existin g one, eith er front

pan el or pr ogra m contr olled entry can be used.

In t his guide, procedur es have been given to define sta nda rds a nd

ass ign class es. This section will list th e steps r equir ed for front

panel entry of the standa rds a nd a ppropriate labels.

Front Pan el Procedu re: (P-Band Waveg uide Exam ple)

1. Prior t o modifying or gener at ing a cal kit , store one or both of th e

cal kits in t he H P 8510s non-volat ile memory to a t ap e or disc file.

2. Select CAL menu , MORE.

3. Prep ar e to modify cal kit 2: press MODIFY 2.

4. To define a standard: press DEFINE STANDARD.

5. Ena ble sta nda rd n o. 1 to be modified: press 1, X1.

6. Select sta nda rd type: SHORT.

7. Specify an offset: SPECIF Y OFF SE TS.

8. En ter th e delay from Table 1: OFFSE T DELAY, 0.0108309, ns.

9. Ent er t he loss from Table 1: OFF SE T LOSS, 0, X1.

10. Ent er the Z0 from Table 1: OFFSE T Z0, 50, X1.

11. En ter th e lower cut off frequ ency: MINIMU M FRE QUE NCY,

9.487 GHz.

12. Ent er th e upper frequ ency: MAXIMUM FRE QUEN CY,

18.97 GHz.

13. Select WAVEGUI DE.

14. Pr epare t o label the new stan dar d: PRIOR MENU, LABEL

STANDARD, ERASE TITLE.

15. Enter PSH ORT 1 by using th e knob, SELECT LETTER soft key

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an d SPACE soft key.

16. Complete t he t itle entry by pressing TITLE DONE .

17. Complete the standard modification by pressing STANDARD

DONE (DEFINE D).

Sta nda rd #1 ha s now been defined for a 1/8 P-band wa veguideoffset sh ort. To define th e rem aining st an dar ds, refer t o Table 1 an d

repea t st eps 4 -17. To define sta nda rd #3, a m at ched load, specify

fixed.

The front pan el procedure t o implement th e class assignmen ts of

Table 2 for th e P-ban d waveguide cal kit a re a s follows:

1. Prep ar e to specify a class: SPE CIFY CLASS.

2. Select st an dar d class S 11A.

3. Inform th e HP 8510A to use sta nda rd n o. 1 for the S 11A clas s of

calibrat ion: l, X1, CLASS DONE (SPECIF IED).

4. Chan ge the class label for S 11A: LABEL CLASS, S 11A, ERASE

TITLE.

5. Ent er t he label of PSH ORT 1 by using the kn ob, the SE LECT soft

key an d th e SPACE soft key.

6. Complete t he label en try procedure: TITLE DONE , LABEL

DONE.

Follow a similar procedure t o enter the r emaining sta nda rd classes

and labels shown below:

Fin ally, cha nge t he cal kit label as follows:

1. Pr ess LABEL KIT.

2. Ent er t he t itle P BAND.

3. Pres s TITLE DONE, KIT DONE (MODIFI ED). The messa ge CAL

KIT SAVED should appear.

This complet es th e ent ire cal kit modificat ion for front pa nel ent ry.

An example of progra mm ed modificat ion over th e HP -IB bus

th rough an externa l controller is shown in th e Intr oduction To

Pr ogra mming s ection of th e Operat ing an d Service manu al (Section

III).

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This appen dix describes dimensiona l considera tions and required

conventions u sed in determ ining th e ph ysical offset length of

calibration standards in sexed coaxial connector families.

Pr ecise measur ement of the physical offset length is required t o

determ ine th e OFFS ET DELAY of a given calibrat ion st an dar d. The

physical offset length of one an d two port sta nda rds is a s follows.

One port sta nda rdDistan ce between calibrat ion p lane an dterminating impedance.

Two port stan dar dDista nce between the Port 1 an d Port 2

calibration planes.

The definition (location) of th e calibrat ion plan e in a calibrat ion

sta nda rd is dependent on the geometry an d sex of the conn ector

type. The calibrat ion plan e is defined a s a p lan e which is

perpendicular t o the a xis of the condu ctor a nd either coincident

with, or a t a fixed distance from, the outer condu ctor m at ing

sur face. This mat ing surface is located at th e conta ct points of the

outer condu ctors of th e test port an d the calibration stan dar d.

To illustr at e th is, consider t he following conn ector type int erfaces:

7mm Coaxial Connector Interface

The calibrat ion pla ne is located coincident to both th e inn er a nd

outer condu ctor m ating surfaces as sh own. Un ique to th is conn ector

type is th e fact tha t th e inn er an d out er conductor ma ting surfaces

ar e located coincident as well as ha ving h erma phr oditic (sexless)

conn ectors. In all oth er coaxial conn ector fam ilies th is is not th e

case.

26

Appen dix BDimen sional Considerat ions In Coaxial Conn ectors

Standard Standard ClassClass Numbers Label

S 11B 2 PSHORT 2

S 11C 3 PLOAD

S 22A 1 PSHORT 1

S 22B 2 PSHORT 2

S 22C 3 PLOAD

FWD TRANS 4 THRU

FWD MATCH 4 THRU

REV TRANS 4 THRU

REV MATCH 4 THRU

RESPONSE 1,2,4 RESPONSE


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Note

During measu remen t calibrat ion using th e HP 85054 N-type

Calibra tion Kit, sta nda rd la bels for th e opens an d short s indicate

both t he sta nda rd type an d the sex of th e calibration test port. Thesex (M or F ) indicates t he sex of th e test p ort, NOT th e sex of th e

standard.

The calibration plane in other coaxial types sh ould be defined at one

of th e condu ctor inter faces to provide a n ea sily verified referen ce for

physical length measurements.

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hp-pn8510-5a_network analysis specifying calibration standards

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