Series 73 12 Bit Digital and Series 74 Analog High Dynamic I-Q Vector Modulators

Contact Us

Application Notes for Microwave Phase Shifter

The new Series 73/74 represents the latest addition to Kratos General Microwave's existing line of PIN Diode I.Q. Vector Modulators. Their performance has been enhanced to provide a higher dynamic range of attenuation for today's more demanding system applications.
All models incorporate multiple bi-phase modulator sections to provide in excess of 60 dB attenuation range at any frequency. All models are also capable of a full 360° range of phase shift. The series covers a frequency range of 2 GHz to 24 GHz in three bands: 2 GHz to 6 GHz, 6 GHz to 18 GHz, and 16 GHz to 24 GHz. A simplified block diagram is shown in Fig. 1.

  • Simultaneous control of amplitude and phase over a 50 dB dynamic range
  • 2 to 24 GHz in three bands:
    • 2 to 6 GHz
    • 6 to 18 GHz
    • 16 to 24 GHz
  • 12 Bit digitally programmable (Series 73)
  • Analog control (Series 74)
  • High speed
  • Guaranteed monotonicity

12 Bit digital/analog high dynamic IQ vector modulators

Series 73, 74 IQ vector modulator block diagram

THEORY OF OPERATION

The block diagram of the I-Q Vector Modulator is shown in Figure 1. An RF signal incident on a 3 dB quadrature hybrid is divided into two equal outputs, with a 90° phase difference between them. The in-phase, or 0°, channel is designated the I channel and the Quadrature, or 90°, channel is designated the Q channel. Each signal passes through a biphase modulator which sets the 0° or 180° state and the attenuation level for both the I and Q paths. The outputs of the I and Q path are combined to yield the resultant vector which may fall anywhere within the bounded area shown in Figure 2. Any signal applied to the I-Q Vector Modulator can be shifted in phase and adjusted in amplitude by applying the following relationships:

  1. Let the desired attenuation level = X dB and the desired phase shift = θ° (with respect to 0 dB and 0° reference states).
  2. The normalized output voltage magnitude is given by: |V| = 10-(x/20).
  3. The values of the I and Q attenuator control inputs are then expressed as:
    I = V cos θ
    and
    Q = V cos θ

Figure 3 shows the nominal value of I and Q vs. either digital word (Series 73) or analog voltage (Series 74). Thus, to achieve an attenuation level of 3 dB with a phase offset of 112.5° (with respect to 0 dB and 0° reference states) the values of I and Q can be calculated as follows:

V = 10–(3/20) = 0.707
I = 0.707 cos (112.5°) =–0.027
Q = 0.707 sin (112.5°) =+0.65

From Figure 3, the control inputs to yield the desired amplitude and phase are approximately:

Analog Units (73 Series) Digital Units (74 Series)
I = 7.81 volts 110010000000
Q = 1.50 volts 001010000000

While these values for I and Q will yield an output signal whose amplitude and phase are close to the nominal values over the entire operating frequency range of the vector modulator, the use of an iterative measurement procedure will determine the I and Q inputs which exactly deine the desired parameter at any selected frequency.

IQ Phase relationship for Series 73,74 modulators
IQ control characteristics 73 and 74 series vector modulators

 

 PERFORMANCE CHARACTERISTICS

MODEL 7322/7422 7328/7428  7329/7429 
Frequency  2.0-6.0 GHz 6.0-18.0 GHz   16.0-24.0 GHz
Insertion Loss (max) 16 dB  20 dB  6-16 GHz
23 dB > 16-18 GHz

21 dB

VSWR (max) 1.8:1  2.3:1 

2.5:1 

Power Handling Without Performance Degredation
+20 dBm
Survival Power (max)
1W
Absolute Insertion Phase Accuracy vs. Frequency (max)
±25°
±22°
Variation of Phase vs. Temperature (max)
± 0.2 deg./ °C
Attenuation Range (min)
50 dB
Variation of Amplitude vs. Temperature (max)
0.04dB/ °C
Response Time (max)
1.0 µsec
Power Supply
-12 to -15V @ 100 mA
+12 to +15V @ 100 mA
Control Input   73 Series   74 Series
12 bit TTL for both I and Q inputs
0 to +10V DC for both I and Q inputs
Control Input Impedance   73 Series   74 Series
 40 µA max
10 K ohms

 

 

ENVIRONMENTAL RATINGS - OPTION G09 ACCESSORIES FURNISHED
Operating Temperature
 Range
..................................

-54°C to + 100°C
Mating power/control connector (Series 73 only)
Non-Operating
Temperature Range
...

-65° to + 125° C
AVAILABLE OPTIONS
Humidity................................ MIL-STD-202F, Method 103B,Cond. B (96 hrs at 95%) Option no.             Description
7
Two SMA (Type-K Model 7X29) male RF connectors
Shock.................................... MIL-STD-202F, Method 213B, Cond. B (75 G, 6 msec)
10
One SMA (Type-K Model 7X29) male (J2) and one SMA (Type-K Model 7X29) female (J1) RF connector 
G09 Guaranteed to meet Environmental Ratings
G12 RoHS Compliant
G16 RoHS Plus REACH Compliant
Vibration.............................. MIL-STD-202F, Method 204D,Cond. B (.06" double amplitude or 15G, whichever is less)  
Altitude.................................. MIL-STD-202F, Method 105CCond. B (50,000 ft.)    
Temp. Cycling...................... MIL-STD-202F, Method 107DCond. A, 5 cycles     

 

  Dimensions and weights for Series 73

 

MODEL A B C D E F G H J K
7322 4.00 ± .03(101,6) 3.00±.03(76,2) .88(22,4) 3.80±.01(96,5) 2.75± .01(69,9) 1.50(38,1)  1.90(48,3)  2.00(50,8)  .68(17,3) .10(2,9)
7328 3.12 ± .03(79,2) 3.00 ± .03(76,2) .88(22,4) 2.92 ± .01(74,2) 2.75 ± .01(69,9) 1.50(38,1) 1.82(46,2) 1.56(39,6) .68(17,3) .10(2,9)
7329 3.25 ± .03(82,6) 3.00 ± .03(76,2) .82(20,8) 3.00 ± .01(76,2) 2.75 ± .01(69,9) 1.50(38,1) 1.69(42,9) 1.62(41,1) .65(16,5) .12(3,0) 

 

J3 PIN FUNCTIONS
PIN FUNCTION PIN FUNCTION
1 I-5 20 I-4
2 I-6 21 I-7
3 I-8 22 I-3
4 I-9 23 I-2
5 I-10 24 I-1 (LSB)
6 I-11 25 I-12 (MSB)
7 N/C 26 N/C
8 +12 to + 15V 27 N/C
9 GND 28 GND
10 GND 29 N/C
11 -12 to -15V 30 N/C
12 Q-3 31 N/C
13 Q-2 32 Q-4
14 Q-1 (LSB) 33 N/C
15 Q-5 34 N/C
16 Q-6 35 Q-12 (MSB)
17 Q-7 36 Q-11
18 Q-8 37 Q-10
19 Q-9    
MODEL WEIGHT (APPROX) 
7322 12 oz. (341 gm)
7328 11 oz. (312 gm)
7329 11 oz. (312 gm)

Dimensional Tolerances, unless otherwise indicated .XX±.02; .XXX±.005

 

  Dimensions and weights for Series 74

 

MODEL A B C D E F G H J K
 7422 4.00 ±.03(101,6) 3.00±.03(76,2) .88(22,4) 3.80 ±.01(96,5) 2.75±.01(69,9) 1.50(38,1)  1.90(48,3)  1.28(32,5)  .68(17,3) .10(2,9)
7428 3.12±.03(79,2) 3.00 ± .03(76,2) .88(22,4) 2.92±.01(74,2) 2.75±.01(69,9) 1.50(38,1) 1.82(46,2) .83(21,1) .68(17,3) .10(2,9)
7429 3.25 ± .03(82,6) 3.00 ± .03(76,2) .82(20,8) 3.00±.01(76,2) 2.75±.01(69,9) 1.50(38,1) 1.69(42,9) 0.90(22,9) .65(16,5) .12(3,0)

 

MODEL WEIGHT (APPROX) 
7422 12 oz. (341 gm)
7428 11 oz. (312 gm)
7429