The Keysight Agilent HP 3708A Noise and Interference Test Set is designed to simulate flat-fade conditions on digital or FM microwave radio receivers by injecting high-accuracy noise into the IF section. It features carrier tracking to maintain a constant carrier-to-noise (C/N) ratio automatically under fading conditions.
Specifications
General
| Parameter | Value |
|---|---|
| Interfaces | HP-IB |
| Display | 7-segment LED display with status indicators |
Physical
| Parameter | Value |
|---|---|
| Power Supply | 100 / 120 / 220 / 240 V AC (+11% / -13%), 48 to 66 Hz, 150 VA max |
| Operating Temperature | 0 to +55 °C |
| Dimensions (W×H×D) | 425 mm × 177 mm × 625 mm |
| Weight | 23 |
Carrier/Interference (C/N and C/I)
| Parameter | Value |
|---|---|
| C/N Ratio Measurement Range | 0 to 40 dB |
| C/I Ratio Range | 0 to 40 dB |
| Auxiliary I Input Function | Provides a fixed-loss path to the IF output, mixing an interferer with C/N to provide C/(N+I) ratios |
Carrier Path Characteristics
| Parameter | Value |
|---|---|
| Carrier Path Gain | 0 ±0.4 dB (typically 0 ±0.1 dB) |
| Carrier Path Group Delay | 0.2 ns |
Power Measurement
| Parameter | Value |
|---|---|
| Power Meter Resolution | 0.01 dB |
| Power Meter Type | TRMS IF power meter |
Measurement Functions
| Parameter | Value |
|---|---|
| Insertion Loss Measurement Range | 35 dB to -5 dB |
| Insertion Loss Measurement Accuracy | ±0.2 dB at 70 or 140 MHz |
| Noise Bandwidth Measurement Range | Function of insertion loss and filter bandwidth |
| Measurement Modes / Unit Entry Options | C/N_0, Eb/N_0, or C/N (C/N in user-defined bandwidth) |
| Tracking Mode Function | Automatically maintains constant C/N ratio in the presence of receiver carrier level variations |
| Interference Facility | Broadband, with or without noise injection, to stress the radio deterministically |
Carrier & Noise Path
| Parameter | Value |
|---|---|
| Carrier Frequency Range | 10 MHz to 140 MHz |
| Nominal Impedance | 75 Ω (standard), 50 Ω (Option 001) |
| Return Loss | > 26 dB (10 to 140 MHz) |
Environmental
| Parameter | Value |
|---|---|
| Storage Temperature | -40 °C to +75 °C |
Power
| Parameter | Value |
|---|---|
| Power Consumption | 150 VA maximum |
Options
| Parameter | Value |
|---|---|
| Option 001 RF Connector and Impedance | 50 Ω impedance, BNC female connectors |
Technology
Analog/Digital IF Noise Injection
Applications
Microwave radio link flat-fade simulation and C/N / C/I characterization