Model 1761 Multi-Octave Digitally Controlled Miniature PIN Diode Attenuator

Application Notes for Microwave Attenuators

Model 1761 is a miniaturized, digitally controlled PIN diode attenuator covering the instantaneous frequency range of
2 GHz to 18 GHz. This model, measuring only 1.34” square and 0.5” thick, provides a monotonic attenuation range of
60 dB with 7-bit (0.5 dB LSB) resolution and 1 microsecond switching speed.

The Model 1761 is an integrated assembly of a dual PIN diode attenuator and a driver circuit consisting of a D/A converter and voltage-to-current converter. The unit is fully temperature compensated. The RF circuit consists of two wide band, T-pad attenuator sections in tandem. The levels of series and shunt currents required to maintain bilateral match at all frequencies is provided by the driver. This arrangement assures monotonicity over the full 2 to 18 GHz operating band at all levels of attenuation and for any programmed attenuation step.

The Model 1761 weighs approximately 1.5 oz. It is configured with SMA female RF connectors and a multipin connector for logic and power. The unit is powered by ±12 to 15V DC and the logic input is TTL compatible.

                             PHASE SHIFT (DEG)

• Miniature
• 2 to 18 GHz
• 7 Bit TTL
• Hermetically sealed

PERFORMANCE CHARACTERISTICS Frequency Range…………………………………….. 2 to 18 GHz Mean Attenuation Range………………………….. 60 dB Inserton Loss, Max…………………………………… 4.5 dB VSWR, max. ……………………………………………. 2.0:1 Flatness     Up to 20 dB…………………………………………. ±1.0dB     Up to 40 dB…………………………………………. ±1.25dB     Up to 60 dB…………………………………………. ±3.0dB Accuracy of Attenuation     0 to 20 dB…………………………………………… ±1.0dB     20 to 40 dB…………………………………………. ±1.5dB     40 to 60 dB…………………………………………. ±2.0dB Monotonicity…………………………………………… Guaranteed Temperature Coefficient…………………………… ±0.02 dB/°C Power Handling Capability     Without Performance Degradation……….. Up to 50 mW cw or peak     Survival Power……………………………………. 2 W average or peak from -65°C to +25°C; derate linearly to 800 mW at 110°C Switching Speed     50% TTL to 90% RF……………………………… 1.0 µsec Programming………………………………………….. 7-Bit TTL Binary Minimum Attenuation Step………………………….. 0.5 dB Logic Input     Logic “0” (Bit OFF)………………………………… -0.3 to +0.8V     Logic”1″ (Bit ON)…………………………………… +2.0 to +5.0V Input Current……………………………………………. 10 µA max.

Power Supply Requirements…………………   +12 to +15V, 100 mA -12 to -15V, 100 mA Power Supply Rejection……………………….  Less than 0.1 dB/volt change in either supply 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 ACCESSORY FURNISHED Mating power/logic connector AVAILABLE OPTIONS G09 Guaranteed to meet Environmental Ratings G12 RoHS & REACH Compliant  G18 REACH Compliant

DIMENSIONS AND WEIGHT Dimensions are stated in inches (mm).  Tolerances, unless otherwise indicated: .XX ±.02; .XXX ±.008 PIN FUNCTIONS PIN    FUNCTION A    GND B    LSB 0.5 dB C    +V D    N.C. E    1 dB F    -V H    N.C. J    4 dB K    2 dB L    N.C. M    16 dB N    8 dB P    GND. R    32 dB