Getting Start with Agilent - ADS Software.

Dr. Haim Matzner, Shimshon Levy and Dafna Ackerman.

July 2008.

2

CONTENTS

0.1 Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1 Background 5

1.1 The Searching Option . . . . . . . . . . . . . . . . . . . . . . . 5

2 Experiment Procedure 9

2.1 Required Equipment . . . . . . . . . . . . . . . . . . . . . . . . 9

2.2 T Attenuator Simulation . . . . . . . . . . . . . . . . . . . . . . 9

2.3 Transmission Line Simulation . . . . . . . . . . . . . . . . . . . 12

0.1 Objectives

Upon completion of the study, the student will become familiar with the fol-lowing topics:

1. Understanding the ability of the Agilent-ADS software.2. Designing basic lumped circuits by applying the Agilent-ADS software.

CONTENTS 3

4 CONTENTS

1. BACKGROUND

Agilent ADS is a leading software for designing and optimizing RF and mi-crowave circuits. When applying the software one can draw a circuit, choosecomponents from the software data base or data-sheet of many manufactur-ers, simulate and optimize the circuit and draw output S parameters or othergraghs of the design.

1.1 The Searching Option

For finding a specific component, click on the ’Display Component LibraryList’ button, as shown in Figure 1.

Figure 1 - ’Display Component Library List’ button.

A component library window should be opened. Press on the ’Find Com-ponent(s)’ button, as shown in Fgure 2.

BACKGROUND 5

Figure 2 - The component library window

A ’Find’ window should be open, as shown in figure 3. Type the name of thedesired component in the ’Find’ tab. Pay attention that the ’Look in:’ tab ismarked as ’All’ (searching option for all ADS directories).

Figure 3 - Find component.

Another way for searching a component is to write its exact name in the com-ponents tab, as shown in Figure 4.

6 BACKGROUND

Figure 4 - Searching a component by its exact name.

A manual searching option is also available by searching the component in thecomponents categories, as shown in Figure 5.

Figure 5 - Components categories.

THE SEARCHING OPTION 7

8 BACKGROUND

2. EXPERIMENT PROCEDURE

2.1 Required Equipment

ADS software installed on a PC computer.

2.2 T Attenuator Simulation

1. Double click on the ADS icon. The main window will open. Open a newproject, by pressing File - New Project, as shown in Figure 1.

Figure 1 - Creating a new window.

Fill in a project name and change the units for the project to mm, as shownin Figure 2.

Figure 2 - New project.

EXPERIMENT PROCEDURE 9

2. New schematic window will be open. Draw a T attenuator, as shown inFigure 3.

3. A 10 dB T-Attenuator, which is also a matching network between 50Ωsystem and 75Ω system. All the components are taken from different categoriesin the left side of the window (see table-1).

4. Set the frequencies range for 1MHz − 500MHz, by double clicking onthe S-PARAMETRS icon. Set the parameters of the substrate (FR4 in ourcase) by double clicking theMSub icon.

R

R3

R=43 Ohm

Zin

Zin2

Zin2=zin(S22,PortZ2)

Zin

N

Zin

Zin1

Zin1=zin(S11,PortZ1)

Zin

N

MSUB

MSub1

TanD=0.002

T=17 um

Hu=1.0e+033 mm

Cond=1.0E+50

Mur=1

Er=4.7

H=1.6 mm

MSub

S_Param

SP1

Step=1.0 MHzStop=500 MHz

Start=1 MHz

S-PARAMETERS

P_1Tone

PORT1

Z=50 Ohm

Num=1

MLIN

TL2

L=50 mm

W=1.3 mm

Subst="MSub1"

MLIN

TL1

L=50 mm

W=3 mm

Subst="MSub1"

Term

Term2

Z=75 Ohm

Num=2

R

R2

R=48 Ohm

R

R1

R=18 Ohm

Figure 3 - T - Attenuator simulation

Component Name Description Categories List

Msub Microstrip substrate TLines-MicrostripTerminaton Term Simulation S_param

MLIN Microstrip Line TLines-MicrostripZin Port Input Impedance Simulation S_ParamR Resistor Lumped Components

S-Parameters S-parameter Simulation Simulation S_ParamP_1Tone Power Source Sources-Freq Domain

Table-1, list for Figure 3

5. Simulate the circuit by clicking on the yellow tooth wheel icon. A debugwindow will be opened, as shown in Figure 4. Pay attention that there is not

any error in the Summary section.

10 EXPERIMENT PROCEDURE

Figure 4 - Debug window.

6. After performing the simulation the results window open, choose the’Rectangular Plot’ button, as shown in Figure 5.

Figure 5 - ’Rectangular Plot’ button.

T ATTENUATOR SIMULATION 11

An options window will be open, choose a parameter (e.g. S(2,1)), click onthe button ’Add Vs...’, choose the data units (in this case, dB), select theindependent variable (in this case, freq) and press ’OK’. You should get, in

the results window, a graph, as shown in Figure 6.

Figure 6 - Results window.

7. Draw the following graphs : S21(dB) (the attenuation) versus frequency,S11(dB) (input return loss) and S22(dB) (output return loss) versus frequency,|Zin| and |Zout| (magnitude of the input and output impedances) versus fre-quency.

2.3 Transmission Line Simulation

1. Draw a 50Ω transmission line terminated by 50Ω load, as shown in Figure7.

12 EXPERIMENT PROCEDURE

ParamSweep

Sweep1

Step=0.5

Stop=160

Start=0

SimInstanceName[6]=

SimInstanceName[5]=

SimInstanceName[4]=

SimInstanceName[3]=

SimInstanceName[2]=

SimInstanceName[1]="SP1"

SweepVar="X"

PARAMETER SWEEP

VAR

VAR1

X=1.0

EqnVar

S_Param

SP1

Freq=1.0 GHz

S-PARAMETERS

MSUB

MSub1

Rough=0 mm

TanD=0.02

T=17 um

Hu=1.0e+033 mm

Cond=1.0E+50

Mur=1

Er=4.7

H=1.6 mm

MSub

MLIN

TL1

L=X mm

W=2.88 mm

Subst="MSub1"

Term

Term2

Z=50 Ohm

Num=2Zin

Zin1

Zin1=zin(S11,PortZ1)

Zin

N

Term

Term1

Z=50 Ohm

Num=1

Figure 7 - 50 ohm trasmission line.

Component Name Description Categories List

Msub Microstrip substrate TLines-MicrostripTerminaton Term Simulation S_param

MLIN Microstrip Line TL-MicrostripZin Port Input Impedance Simulation S_Param

S-Parameters S-parameter Simulation Simulation S_ParamP_1Tone Power Source Sources-Freq Domain

Parameter Sweep Swept parameter simulation Simulation S_ParamTable-2, list for Figure 7

2. Draw the following graphs : S21(dB) (attenuation) versus the length X,Zin (input impedance) versus the length X and S21(phase) (phase response)versus the length X, as shown in Figures 8 and 9.

20 40 60 80 100 120 1400 160

-0.4

-0.3

-0.2

-0.1

-0.5

0.0

X

dB

(S(2

,1))

Figure 8 - Attenuation versus the length X.

TRANSMISSION LINE SIMULATION 13

20 40 60 80 100 120 1400 160

-100

0

100

-200

200

X

ph

ase(S

(2,1

))

Figure 9 - Phase response versus the length X.

3. Draw a 50Ω transmission line terminated by a short, as shown in Figure 10.

Term

Term2

Z=0.001 mOhmNum=2

ParamSweep

Sweep1

Step=0.5

Stop=160Start=0

SimInstanceName[6]=

SimInstanceName[5]=SimInstanceName[4]=

SimInstanceName[3]=SimInstanceName[2]=

SimInstanceName[1]="SP1"

SweepVar="X"

PARAMETER SWEEP

VAR

VAR1

X=1.0

EqnVar

S_Param

SP1Freq=1.0 GHz

S-PARAMETERS

MSUBMSub1

Rough=0 mm

TanD=0.02T=17 um

Hu=1.0e+033 mmCond=1.0E+50

Mur=1

Er=4.7H=1.6 mm

MSub

MLIN

TL1

L=X mm

W=2.88 mm

Subst="MSub1"ZinZin1

Zin1=zin(S11,PortZ1)

Zin

N

Term

Term1

Z=50 Ohm

Num=1

Figure 10 - 50 ohm trasmission line terminated by a short.

4. Draw the following graphs: the attenuation, S21(dB), versus the lengthX, the input impedance, Zin, versus the length X and the phase response,S21(phase), versus the length X.

14 EXPERIMENT PROCEDURE