Table 1-1. Models 800N801 Specifications

MODEL 800A GUNN PHASE LOCK MODULE

IF IN: 1 MHz to 200 MHz, -70 dBm to -20 dBm.

J1: Control connector to Model 801 Control Unitor customer system.

GUNN (OUT):

DAMPING:

2.5 VDC to 11 VDC, 1.5 A to Gunn Oscillator.

Adjusts transient response of phase-lock loop.

+ 15 (IN):

SPAN:

Requires + 15 VDC :t 1 V, 2 A.

Adjusts range of voltage to Gunn Oscillator(nominal 3 V range).

BASE VOLTS: Adjusts minimum oscillator voltage(setable from 2.5 VDC to 7.5 VDC).

20 MHz to 100 MHz, -10 dBm to +15 dBm.

1 MHz to 200 MHz (nominal -30 dBm).

1 lb. 7 oz.

REF (IN):

IF MON:

WEIGHT:

SIZE: 7" X5" X1-1/2" (Lx W x H).

6-3/8" L x 4-1/2" W.CHASSIS MOUNTINGHOLE CENTERS:

MODEL 801 CONTROL MODULE

SIZE:

14 oz. (not includingcable).

6-1/4" x 3-3/4" x 2 (L x W x H).

WEIGHT:

CABLE: 1-meter cable supplied.

800/91JAN01

1-1. OPERATION.

1-1.1. The XLModel 800A Gunn Phase Lock Module contains the necessary circuitry to lock aGunn oscillator to the harmonic of a lower frequency reference (:!: offset) with high spectralpurity and ease of use.

1-1.2. The Model 800Aincludes a bias circuit that setsthe operating point of the Gunnoscillator,thereby supplying power to the oscillator. The external control voltage (0 to 10volts) is scaledto a 3 volt range.

1-1.3. The reference frequency buffer amplifies and limits the input (20 to 100 MHz) to drive thetwo phase detectors. It operates over the range of -10 dBm to + 15 dBm. The IF amplifier coversthe range of 1 MHz to 200 MHz and has a noise figure of approximately 5 dB. Locking can occurfor an IF level of approximately -70 dBm or greater. This is the level at which the AGC circuitbegins to operate and it is also the threshold of the IF level indicator. A seperate buffer amplifieris supplied to monitor the IF signal on a spectrum analyzer.

1-1.4. The sweep bias circuit injects a current into the integrator amplifier in a manner thatsweeps the operating voltage :!:0.4 volts above and below the nominal operating voltage thatwas set by the biascircuit. Since Gunn oscillators typically havea voltage tuning characteristic,this sweeps the oscillator frequency back and forth.

1-1.5. If the IF frequency (Fosc-N Fo) becomes equal to the reference frequency and the IFlevel is large enough, locking will occur. After lock, the sideband select circuit checks to see ifthe lock is on the proper sideband (nominally the upper sideband). If it is, the lock indicator isturned on. If it isthe wrong sideband, the IFamplifier is turned off momentarily so that the sweepresumes.

1-1.6.The Model 801 Control Unit is available to monitor and control the IF level, RF controlvoltage and on/off of the sweep, oscillator and IF monitor.The unit also has a lock monitor.

1-2. USING MODELS 800A/801 IN A SYSTEM

1-2.1. Figure 1 below shows a simplified diagram of how to use the 800N801 in a Gunn system.

GUNNOSCILLATOR

REFIN

GUNN

DIPLEXER

MODEL800

IFin

IF LEVEL CONTROLVOLTS 2 -10 GHz

MICROWAVEREFERENCE

(Fo)MODEL 801

Figure 1.Using Model 800N801 ina Gunn system.

800/91JAN01

1-3. SYSTEM INSTALLATIONI

1-3.1. The operating voltage and loop gain are controlled by 0 -10 VDC voltages and are scaledinternally. The input circuits are illustrated below in Figure-2.

--

TOINTERNALCIRCUITS

+10 VOLT REFERENCE

Figure 2. 800A Input Circuits.

1-3.2. The internal 10 volt reference may be used to control the unit, or you may use an external0-10 volt signal. In either case, both of the differential amplifier inputs may be used_Thecommon mode voltage on both inputs must be less than 10volts.

1-3.3. The status and control bits are TTL compatible, and an external LED "lock" indicator maybe wired to the input as shown below in Figure 3.

+15

}EXTERNAL

-LED

Figure 3. External "Lock" LED Wiring.

800/91JAN01 2

IFMONITOR

OUT

1 MHz-250 MHZ AGC{LEVEL

CIRCUIT

SIDEBANDSELECTCIRCUIT

-LOCK

INDICATOR

IFLEVEL IFMON

ON/OFF

CONTROLVOLTS

NOTE: SHADED AREASINDICATE CIRCUITS

BUILT INTO MODEL 801CONTROL UNIT.

Figure 4. 800N801 Block Diagram

800/91JAN01 3

Vop VIg +15+10 +10V

OSCON/OFF, BIASCIRCUIT,

)

REFBUFFER , I- I I I L-

SWEEP

SWEEPFF

BIAS

, I , nD! , - ,NOMINAL80 MHz

PHASE lOCKING A GUNN OSCilLATOR: .

. XL.MODEL

801

Xl.MODEL

80DA

MILLIMETEROUTPUT

LOCALOSCILLATORMICROWAVEREF

(2 GHz-20 GHz)

)

Figure 5. Simplified Interconnection Diagram

800/91JAN01 4

CONTROL GUNN PHASE GUNNCOUPLERMODULE LOCKMODULE OSCILLATOR

REF j t IFINOSCILLATOR ,..15V(20 MHz-lOa MHz) i

DIPLEXER HARMONIC

I

MIXER

Q,.+/ov

(sO( NM/.)

L I I I

0... +IOV

3

Figure 6. Model 800A 'D' Connector (J5) Pinout

aOO/91JAN01 5

+ - I_.

':'

''''I

Tf'II . . 1-0 :L:=ON(TTL.J

+,

REF.l.E-\

+-=OFF

-=

,..JI4-

I I

f< I

I REFUEII(.E, 7S.TA1'IIf--ITr RE.FLE.VE.L5TA-T1.15

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