II. Model Interpretation

PXI represents that the equipment follows the PXI industrial bus standard and adopts a 3U structure, occupying a single cabinet slot, and is compatible with both PXI and PXIe chassis.

5651 belongs to the NI 5650 series RF signal generator. This series is a general-purpose RF analog signal source product line. The digital number distinguishes the frequency ranges. 5651 corresponds to the highest working frequency of 3.3 GHz version.

The standard complete component number is 778284-02.

III. Technical Parameters

All of these parameters are typical values under a 25-degree Celsius environment and a 50-ohm standard load.

1. Frequency Parameters

Operating frequency range: 50 kHz to 3.3 GHz. The signal can be probed down to 100 kHz. There are no calibration indicators in this range.

Frequency resolution: Less than 3 Hz in the 500 kHz to 1.3 GHz range, and less than 6 Hz in the 1.3 GHz to 3.3 GHz range.

Annual frequency stability: ±0.1 ppm

Phase noise: At a one GHz carrier, a 10 kHz frequency offset is less than -110 dB per Hz.

2. Output Power Parameters

500 kHz to 10 MHz range: Power range from -90 dBm to 5 dBm

10 MHz to 50 MHz range: Power range from -90 dBm to 8 dBm

50 MHz to 3.3 GHz range: Power range from -90 dBm to 12 dBm

Power resolution: Less than 0.1 dB

Typical power accuracy: ±0.5 dB

3. Modulation Parameters

Supports frequency modulation function. Maximum frequency offset: ±1 MHz

Supports dual-frequency shift keying function. Frequency offset can be programmed by software.

Supports on-off keying function. Achieves amplitude on-off control.

4. Interference and Harmonic Parameters

Harmonic components: Typical value less than -15 dB carrier

Non-harmonic stray signals: Typical value less than -60 dB carrier

5. Physical and Environmental Parameters

Equipment specification: 3U single-slot structure

Overall power consumption: Approximately 18 watts

Operating temperature range: 0 degrees Celsius to 55 degrees Celsius

Cooling method: Forced air cooling of the chassis

IV. Interface and Communication Configuration

Front panel interface

RF output interface: Uses SMA interface, with a standard impedance of 50 ohms, for outputting RF signals

Reference clock input interface: Uses SMA interface, connecting a 10 MHz external reference clock to achieve multi-device synchronization

Bus and software configuration

The device backplane is equipped with a standard PXI bus, including 32-bit PCI bus, PXI trigger bus, and 10 MHz reference bus, supporting signal triggering and clock sharing between devices.

The accompanying driver program is NI-RFSG, which can be used in development environments such as LabVIEW TestStand, Python, and C#.

Supports NI-TClk synchronization technology, enabling phase synchronization of multiple modules.

V. Core Functions

1. Wideband continuous wave output, covering very high frequency, extremely high frequency, cellular high frequency bands, and some microwave frequency bands, meeting the requirements of medium and high frequency RF frequencies.

2. Built-in high-stability constant temperature crystal oscillator, with strong frequency stability and excellent phase noise indicators, ensuring the accuracy of medium and high frequency RF measurements.

3. Integrates various basic modulation functions, capable of directly outputting frequency modulation, frequency shift keying, and on-off keying signals, without the need for additional baseband modules.

4. Equipped with automatic level control function, ensuring stable output power and weakening the impact of temperature changes and load fluctuations.

5. Standard PXI modular design, compatible with the same platform RF acquisition, analysis modules, and capable of building a complete automated RF test system.

6. Adequate high-frequency output power, suitable for the power testing requirements of medium and high-frequency RF devices and wireless equipment.

VI. Application Scenarios 1. Wireless communication testing, used for testing the receiver sensitivity and anti-interference capability of second-generation, third-generation, fourth-generation mobile communication devices, wireless local area networks, Bluetooth, and low-power wireless devices, especially suitable for high-frequency communication equipment.

2. RF component testing, completing the gain loss and linearity detection of RF amplifiers, filters, mixers, RF switches and other devices, covering mid-high frequency devices.

3. Radar and electronic equipment testing, outputting basic continuous waves and modulated RF signals, simulating simple radar excitation signals and RF environment, suitable for mid-high frequency radar equipment.

4. Aerospace and defense field, used for calibrating military RF equipment, RF link simulation and exciting various RF sensor signals.

5. Automotive electronics testing, conducting functional and anti-interference tests for RF modules such as vehicle remote key, tire pressure monitoring, and vehicle Bluetooth.

Seven. Installation and Maintenance Instructions

Installation and Power On

The equipment must be installed in a power-off state, fixed in a single slot of the PXI chassis, and the chassis should be reliably grounded to prevent static damage to the hardware.

After installation, power on the equipment, preheat for thirty minutes to ensure that the internal constant temperature crystal oscillator reaches a stable working state. Use the NI MAX software to complete the equipment self-check and confirm there is no hardware fault.

During operation, ensure that the air duct of the chassis is unobstructed, the working environment temperature does not exceed 55 degrees Celsius, and do not block the chassis cooling fan.

Cable Connection and Operation

The RF output terminal uses a 50-ohm standard SMA coaxial cable for connection, tighten the interface to reduce signal reflection and loss.

It is not recommended to short-circuit the RF output interface for a long time for grounding, to avoid damaging the final amplification circuit of the equipment, and prefer to use a 50-ohm matching load.

When working with multiple devices in synchronization, uniformly connect to an external 10 MHz reference clock, enable the synchronization function, and ensure that the phases of all devices remain consistent.

Daily Maintenance and Calibration

It is recommended to conduct a professional trace calibration once a year to compensate for the parameter offset caused by long-term use of the equipment. Daily use can use the built-in self-calibration function of the equipment to correct the performance changes caused by temperature.

Regularly use a drying tool to clean the dust on the SMA interface surface to keep the interface dry and clean. When the equipment is idle for a long time, install a dust cap on the interface.

The equipment storage and usage environment should be free of condensation, with the environmental humidity controlled between 10% and 90%. Stay away from strong electromagnetic interference equipment and severe vibration sources.

Do not plug or unplug the signal cables while the equipment is powered on to avoid the equipment being impacted and subjected to severe vibration. Do not operate for a long time in an environment exceeding the rated temperature.