Microwave Attenuator: Series D195

 

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Application Notes for Microwave Attenuator

The Series D195 voltage-controlled linearized attenuator/modulators are integrated assemblies consisting of a Series 195 unit and a hybridized driver circuit which provides a nominal transfer function of 10 dB per volt. (See figure 1 below.) Series D195 block diagram
All of the Series D195 units except the D195OA* exhibit fall times of 20 nsec max and rise times of 1.5 µsec max for attenuation steps of 10 dB or more. For smaller excursions, the fall times can increase to several hundred nsec, while the rise times remain essentially unchanged. In applications where a rapid return to insertion loss from any level of attenuation is required, Option 59 is available. With this option, an external pulse is applied to trigger a high-speed reset circuit, and recovery times of 200 nsec max are obtained. Where use of an external reset pulse as described above is not feasible, an internal reset option (Option 58) is available which will automatically reset the unit to insertion loss within 200 nsec for a step of 50 dB or more. The fall and rise time specifications for the D1950A* are 500 nsec max and 10 µsec max, respectively. Options 58 and 59 are not available for this model.

*Model D1950A is a special-order product. Consult factory before ordering.

 

  • Absorptive
  • Linearized
  • Frequency range: 0.5 to 18 GHz
  • High performance MIC quadrature hybrid design
  • High speed

 

Series D195 Octave-Band PIN diode attenuator/modulator
ALL UNITS
IN THIS SERIES
ARE EQUIPPED
WITH INTEGRATED DRIVERS

 

MODEL FREQUENCY RANGE (GHz)

MAX. INSERTION LOSS (dB)

MAX. VSWR MAX. FLATNESS (±dB)
AT MEAN ATTENUATION LEVELS UP TO
 10 dB 20 dB 40 dB 60 dB 80 dB
D1950A* 0.5 - 1.0 1.5 2.0 0.3 0.8 1.7 3.0 3.6
D1951 1.0 - 2.0 1.7 1.5 0.3 0.8 1.5 1.6  
0.75 - 2.25(1) 1.8 2.0 0.5 1.4 3.0 3.5
D1952 2.0 - 4.0 2.0 1.5 0.3 0.8 1.5 1.6
1.5 - 4.5(1) 2.1 2.0 0.5 1.4 3.0 3.5
D1953 2.6 - 5.2 2.2 1.6 0.3 0.8 1.5 1.8
1.95 - 5.85(1) 2.3 2.1 0.5 1.4 3.0 3.5
D1954 4.0 - 8.0 2.6 1.7 0.3 0.8 1.5 1.6
3.0 - 9.0(1) 2.7 2.2 0.5 1.4 3.0 3.5
D1955 5.0 - 10.0 2.8 1.7 0.5 0.9 1.5 1.6
3.75 - 11.25(1) 2.9 2.2 0.7 1.4 3.0 3.5
D1956 6.0 - 12.0 2.9 1.8 0.7 1.0 1.5 1.6
4.5 - 13.5(1) 3.0 2.2 0.9 1.5 3.0 3.5
D1958 8.0 - 18.0 3.0(2) 1.8(2) 0.7 1.0 1.5 1.6
6.0 - 18.0(1) 3.0(2) 1.8(2) 0.9 1.5 3.0 3.5

*Model 1950A is a special-order product. Consult factory before ordering.

(1) Specifications for the extended frequency ranges are typical.

(2) Except from 16 - 18 GHz where insertion loss is 4.0 dB max and VSWR is 2.0 max.

PERFORMANCE CHARACTERISTICS

Mean Attenuation Range
   D1950A* .......................... 80 dB
   All other units ................... 60dB
Accuracy of Attenuation
   O to 3OdB ....................... ±0.5 dB
   > 30 to 50 dB ................... ±1.0 dB
   > 50 to 60 dB ................... ±1.5 dB
   > 60 to 80 dB ................... ±2.0 dB
(D195OA*only)
Monotonicity ...................... Guaranteed
Phase Shift ........................ See Application Note
Temperature Coefficient ...... ±0.025 dB/ C
Power Handling Capability
   Without Performance Degradation
      D1950A*,D1951 ............ 10 mW cw or peak
      All other units ................ 100 mW cw or peak
Survival Power (from -65%C to +25%C;
see Fig. 2 for higher temperatures)
       All units.......................... 1 W average 25W peak (1 µsec max pulse width)
Switching Characteristics
   Off Time
      D195OA* ................... 600 nsec max
      All other units ............. 100 nsec max
   On Time
      D1950A* ................... 10 µsec max
      All other units ............. 1.6 µsec max
   Fall Time
      D1950A* ................... 500 nsec max
      All other units ............. 30 nsec max
   Rise Time
      D195OA* ................... 10 µsec max
      A ll other units ............. 1.5 µsec max

Nominal Control Voltage Characteristics Range
       Operating   Maximum
D195OA*   0 to + 8V     ± 15V  
All Other Units     0 to + 6V    ± 15V  

Transfer Function .................
10 dB / volt
Input Impedance ...................
10 Kohms
Modulation Bandwidth
   Small Signal
      D195OA* ................... 25 kHz
      All other units ............. 500 kHz
   Large Signal
      D195OA* ................... 5 kHz
      All other units ................. 50 kHz
Power Supply
   Requirements ..............
+12V  ±5%, 100 mA
-12V  ±5%, 50 mA
Power Supply
   Rejection .....................
Less than 0.1 dB / volt change in either supply

*Model 1950A is a special-order product. Consult factory before ordering.

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
3 SMA female control connector
7 Two SMA male rf connectors
10 One SMA male (J1) and one SMA female (J2) RF connector
58 Internally-generated reset to insertion loss (not available on D1950A)(1)
59 Externally-triggered reset to insertion loss (not available on D1950A*)(2)(3)
61 20 dB / volt transfer function with 0 to +3V control signal input (+4V for the D1950A*)
62 ± 15 volt operation
64 SMC male control connector
64A SMB male control connector

 G09 Guaranteed to meet Environmental Ratings
G12 RoHS Compliant
G16 RoHS Plus REACH Compliant

(1) Where use of an Option 59 external reset pulse (see note 2 below) is not feasible, this option is available which will
      automatically sense the slope and magnitude of the control signal and reset the unit to the insertion loss state within
      200 nsec for a stop of 50 dB or more.
(2) An external terminal is provided for the user to apply a fast (10 nsec, max rise time) positive-going 3-volt pulse at
      least 0.5 µsec wide to accelerate the return of the attenuator to the insertion loss state with the simultaneous
      lowering of the control signal to the zero voltage level. This reset can be accomplished within 200 nsec.
(3) The input impedance of units equipped with Option 59 is a circuit equivalent to approximately 50 pF in series with a
      parallel combination of 100 pF and 1000 ohms.


 Series D195 power derating factor

Dimensions and Weights

Series D195 attenuator/modulator dimensions and weight

* Model 1950A is a special-order product.  Consult factory before ordering.

 

 

 

 

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