Kratos Microwave Electronics Division (KMED)

Full Line Product Catalog

Microwave Phase Invariant Attenuator Series 347

Application Notes for Microwave Attenuators

The Series 347 digitally controlled PIN diode attenuators offer essentially phase free operation over a wide dynamic range in multi-octave frequency bands between 2 and 18 GHz. The attenuators utilize a unique double balanced arrangement of diodes and quadrature couplers to achieve the phase independent attenuation characteristic. Excellent temperature stability is maintained by employing a self-compensating biasing scheme. See Fig. 1.

Series 347 attenuator RF schematic diagram
Special Order Product Consult Factory Before Ordering
  • Low Phase Shift
  • Frequency range: 2-18 GHz
  • Non-reflective
  • Attenuation range: to 45 dB
  • LSB: 0.125 dB
  • High Speed
Microwave attenuator series 347 

 TYPICAL PERFORMANCE

series 347 attenuation vs frequency performance diagram series 347 phase vs frequency performance diagram 

PERFORMANCE CHARACTERISTICS

MODEL 3472 3474 3478
Frequency Range (GHz) 2-6 4-11 6-18
Mean Attenuation Range 32 dB
Insertion Loss (Max) 4 dB 5 dB 7 dB
VSWR (Max) 2.0 2.0 3.0
Accuracy of Attenuation ± 0.5 dB
Amplitude Flatness                0 to 20 dB
                                            > 20 to 32 dB		 ± 0.4 dB
± 0.6 dB		 ± 0.4 dB
± 0.8 dB		 ± 0.8 dB(1)
± 1.3 dB(1)
Monotonicity Guaranteed
Phase Shift                             0 to 20 dB
                                            > 20 to 32 dB		 ± 4 °
± 8 °		 ± 4 °
± 8 °		 ± 5 °
± 10 °
On Time, Off Time 350 nsec
Temperature Coefficient .02 dB/°C
Max. RF Power Input (Operating) 100 mW
Max. RF Power Input (Survival) 0.5 W
Harmonic Distortion @ Pin = +10 dBm -40 dBc -50 dBc -50 dBc
Control 8 bit TTL, 0.125 dB LSB
Control Input Impedance @ Logic "0" (- 0.3 to +0.8 V) 500 µA max.
@ Logic 1" (+2.0 to +5.0 V), 100 µA max.
Logic Input Logic "0" = Bit OFF Logic "1" = Bit ON
Power Supply Requirements     +5V ± 5% @ 325 mA
+15V ± 5% @ 15 mA
-15V ± 5% @ 70 mA

SPECIFICATIONS with EXTENDED RANGE OPTION (OPTION 45)

Mean Attenuation Range 45 dB
Accuracy of Attenuation ± 1.0 dB
Amplitude Flatness
0 to 20 dB
> 20 to 32 dB
> 32 dB

± 0.4 dB
± 0.6 dB
± 1.5 dB
± 0.4 dB
± 0.8 dB
± 1.5 dB
± 0.8 dB(1)
± 1.3 dB(1)
± 2.0 dB
Phase Variation
0 to 20 dB
> 20 to 32 dB
> 32 dB
± 4 °
± 8 °
± 15 °
± 4 °
± 8 °
± 20 °
± 5 °
± 10 °
± 30 °

Control

 8 bit TTL, 0.176 dB LSB

(1) Except from 8-18 GHz, flatness is ± 0.5 dB up to 20 dB, ± 1.0 dB up to 32 dB.

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OPTION (G09) ENVIRONMENTAL RATINGS
Operating Temperature Range.................... -54°C to + 110°C
Non-Operating Temperature Range............ -65°C to + 125°C
Humidity.................................................... MIL-STD-202F, Method 103B, Cond. B (96 hrs. at 95%)
Shock........................................................ MIL-STD-202F, Method 213B, Cond. B (75G, 6 msec)
Vibration................................................... MIL-STD-202F, Method 204D, Cond. B (.06" double amplitude or 15G, whichever is less)
Altitude..................................................... MIL-STD-202F, Method 105C, Cond. B (50,000 ft.)
Temp. Cycling............................................. MIL-STD-202F, Method 107D, Cond. A, 5 cycles
.
       AVAILABLE OPTIONS
       Option No. Description
7 Two SMA male RF connectors
10 One SMA male (J1) and one SMA female (J2) RF connectors
45 Extended attenuation range to 45 dB
 65 ± 12V operation
G09 Guaranteed to meet Environmental Ratings
G12 RoHS Compliant
G18 REACH Compliant
   

        ACCESSORY FURNISHED
        Mating power/logic connector
J3 PIN FUNCTIONS
PIN NO. BINARY OPTION 45
1 -15V -15V
2 +15V +15V
3 Do Not Connect Do Not Connect
4 0.125dB(LSB) 0.18 dB
5 0.5 dB 0.70 dB
6 4 dB 5.62 dB
7 16 dB (MSB) 22.5 dB
8 8 dB 11.25 dB
9 GROUND GROUND
10 NOT USED NOT USED
11 2 dB 2.81 dB
12 0.25 dB 0.35 dB
13 1 dB 1.41 dB
14 NOT USED NOT USED
15 +5V +5V

 DIMENSIONS AND WEIGHT

Dimensions are stated in inches (mm).  Tolerances, unless otherwise indicated: .XX ±.02; .XXX ±.008

 MODEL  A B C D E
 3472  2.5 (63,5)  2.26 (57,4)  2.28 (57,9)  0.22 (5,6)  1.25 (31,7)
 3474  2.0 (50,8)  1.76 (44,7)  2.43 (61.7)  0.18 (4,6)  1.0 (25,4)
 3478  2.0 (50,8)  1.76 (44,7)  2.58 (65,5)  0.18 (4,6)  1.0 (25,4)
 


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