II. Model Interpretation

PXI: Standard 3U PXI bus, single slot, compatible with PXI/PXIe chassis.

5600: NI 5600 series RF downconverter model number:

56xx: RF/microwave instrument series;

xx00: Basic broadband downconverter (without integrated digital instrument).

Component number: 778283-01 (standard configuration, unique model).

Combination model: PXI-5600 + PXI-5142 = PXI-5661 VSA.

III. Technical Parameters (25℃, 50 Ω, typical values)

1. Frequency and Bandwidth

RF input frequency: 9 kHz – 2.7 GHz

Real-time bandwidth: 20 MHz (fixed IF bandwidth)

Output intermediate frequency (IF): 5 – 25 MHz

2. Input/Output Characteristics

RF input: SMA female, 50 Ω, AC coupling

Maximum input power: +30 dBm

Attenuation: 0 – 50 dB (10 dB step)

Noise density: < -135 dBm/Hz

IF output: SMA female, 50 Ω, 0 dBm full scale

3. Time Base and Stability

Reference source: Built-in 10 MHz OCXO (highly stable constant-temperature crystal oscillator)

Frequency stability: ±20 ppb (annual)

Frequency accuracy: ±50 ppb

Phase noise: < -94 dBc/Hz @ 10 kHz offset (1 GHz carrier)

4. Dynamic Range and Spurious

Spurious-free dynamic range (SFDR): > 80 dB

Third-order intermodulation: > 70 dBc

5. Physical and Environmental

Size: 3U single slot (approximately 160×100 mm)

Power consumption: approximately 18 W

Operating temperature: 0 – 55℃

Cooling: Forced air cooling (chassis fan)

IV. Interface and Communication Configuration

1. Front Panel (3×SMA)

RF IN (SMA): RF signal input, 50 Ω, AC coupling

IF OUT (SMA): Intermediate frequency output after downconversion, connected to PXI-5142's IF IN

REF IN (SMA): 10 MHz external reference input (-5 to +15 dBm), used for multi-card synchronization

2. Backplane and System Interface

PXI backplane: 32-bit PCI, PXI trigger bus (TRIG0–TRIG6), 10 MHz reference bus

Synchronization: Supports PXI trigger, NI-TClk multi-module phase synchronization

Driver: NI-RFSA (RF vector signal analysis driver), compatible with LabVIEW/TestStand/Python/C#

V. Core Functions

Broadband RF downconversion: 9 kHz – 2.7 GHz → 5 – 25 MHz IF, 20 MHz real-time bandwidth, covering mainstream wireless/radar frequency bands.

Highly stable OCXO time base: ±20 ppb stability, low phase noise, ensuring precise frequency and modulation measurement.

Large dynamic range: +30 dBm full scale, < -135 dBm/Hz noise density, > 80 dB SFDR, suitable for scenarios with both strong and weak signals.

Modular combination: Seamless integration with PXI-5142 (14-bit/100 MS/s digital instrument), quickly building PXI-5661 VSA.

Multi-card synchronization: Shared 10 MHz reference + NI-TClk, multi-module synchronization accuracy < 20 ps, supporting MIMO/multi-channel RF testing. VI. Application Scenarios

Wireless communication testing: 2G/3G/4G/5G (Sub-6G), WiFi, Bluetooth signal reception and demodulation, receiver sensitivity / anti-interference testing.

Radar / Electronic Warfare: Intermediate frequency acquisition in radar, pulse train / LFM signal analysis, electronic countermeasures (ECM) signal monitoring.

Aerospace / Defense: Low spurious RF reception, sensor simulation, military RF equipment calibration and verification.

Semiconductor testing: RF amplifier / filter / mixer performance verification, transceiver chip (SoC) modulation accuracy testing.

General RF R&D: Broadband signal capture, spectrum analysis, modulation quality (EVM / phase error) measurement.

VII. Usage and Maintenance Instructions

1. Installation and Power On

Power off installation, single slot fixed; chassis reliable grounding to prevent static electricity.

Power on preheating for 30 minutes (OCXO requires stable temperature), NI MAX self-check without hardware errors.

Keep ventilation during operation, temperature ≤ 55℃, avoid blocking the chassis fan.

2. Wiring and Operation

RF input uses 50 Ω high-precision SMA coaxial cable, tighten the connector, reduce standing wave.

Input power must not exceed + 30 dBm, otherwise burn the front end; strong signals (> 0 dBm) must be attenuated.

Multi-card synchronization: share 10 MHz reference (REF IN), enable NI-TClk, ensure phase coherence.

3. Calibration and Maintenance

Calibration cycle: recommended 1-year NIST traceable calibration; daily use internal self-calibration to compensate for temperature drift.

Interface maintenance: regularly clean SMA interface, keep dry; install dust cover for long-term inactivity.

Environmental requirements: no condensation, humidity 10%–90% RH; away from strong electromagnetic interference and vibration sources.

Prohibited operations: plug and unplug cables while powered on, overheating operation, interface overload, severe vibration.