Application Notes for Microwave Attenuators
The Series D197 voltage 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.)
- Low phase shift
- Frequency range: 2-18 GHz
- Non-reflective
- Attenuator range: to 45 dB
- Linearized control: 10 dB/V
- High speed
TYPICAL PERFORMANCE
PERFORMANCE CHARACTERISTICS
| MODEL | D1972 | D1974 | D1978 |
| 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 | 3.0 | |
| Accuracy of Attenuation | ± 0.5 dB | ||
| Amplitude Flatness 0 to 20 dB >20 to 32 dB |
± 0.4 dB | ± 0.4 dB | ± 0.8 dB(1) |
| ± 0.6 dB | ± 0.8 dB | ± 1.3 dB(1) | |
| Monotonicity | Guaranteed | ||
| Phase Shift 0 to 20 dB >20 to 32 dB |
± 4° | ± 4° | ± 5° |
| ± 8° | ± 8° | ± 10° | |
| Control Voltage | 0-3.2 V | ||
| Control Input Impedance | 10 kohms | ||
| Transfer Function | 10 dB/V | ||
| On Time, Off Time | 250 ns | ||
| Temperature Coefficient 0 to 20 dB >20 to32 dB |
0.01 dB/°C | ||
| 0.03 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 |
| Power Supply Requirements | +15V ±5% @ 200 mA | ||
| -15V ±5% @ 120 mA | |||
SPECIFICATIONS With EXTENDED RANGE OPTION (OPTION 45)
| Mean Attenuation Range | 45 dB | ||
| Accuracy of Attenuation 0 to 20 dB >20 to 32 dB >32 dB |
± 1.0 dB | ||
| ± 2.0 dB | |||
| ± 3.5 dB | |||
| Amplitude Flatness 0 to 20 dB >20 to32 dB >32 dB |
± 0.4 dB | ± 0.4 dB | ± 0.8 dB(1) |
| ± 0.6 dB | ± 0.8 dB | ± 1.3 dB(1) | |
| ± 1.5 dB | ± 1.5 dB | ± 2.0 dB | |
| Phase Variation 0 to 20 dB >20 to 32 dB >32 dB |
± 4° | ± 4° | ± 5° |
| ± 8° | ± 8° | ± 10° | |
| ± 15° | ± 20° | ± 30° | |
(1) Except from 8-18 GHz, flatness is ± 0.5 dB up to 20 dB, ± 1.0 dB up to 32 dB.
|
|
|||||||||||||||||||||||||||||
DIMENSIONS AND WEIGHT
Weight: 5 oz. (142 gr) approx.
Dimensions are stated in inches (mm). Tolerances,
unless otherwise indicated: .XX ±.02; .XXX ±.008
| MODEL | A | B | C | D | E | F | G | H |
| D1972 | 2.5 (63,5) | 2.26 (57,4) | 2.28 (57,9) | 0.22 (5,6) | 0.91 (23.1) | 1.25 (31,7) | 1.5 (38,1) | 1.7 (43,2) |
| D1974 | 2.0 (50,8) | 1.76 (44,7) | 2.43 (61,7) | 0.18 (4,6) | 0.66 (16,8) | 1.0 (25,4) | 1.25 (31,7) | 1.45 (36,8) |
| D1978 | 2.0 (50,8) | 1.76 (44,7) | 2.58 (65,5) | 0.18 (4,6) | 0.66 (16,8) | 1.0 (25,4) | 1.25 (31,7) | 1.50 (38,1) |