II. Model Interpretation

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

5691 belongs to the NI RF signal conditioning product series, representing a dual-channel RF amplifier with a working frequency upper limit of 8 GHz.

The standard complete component number is 781035-01.

III. Technical Parameters

The following parameters are typical values after the equipment has preheated for ten minutes under a 25-degree Celsius environment and a 50-ohm standard load.

1. Frequency and Channel Parameters

Working frequency range: 50 MHz to 8 GHz

Number of channels: Dual channels, including a fixed gain channel and a programmable gain channel

2. Gain Parameters

Fixed gain channel: Nominal gain 25 dB, noise figure no more than 5 dB

Programmable gain channel: Gain range 0 dB to 31.5 dB, adjustment step 0.5 dB, supports direct-through mode

Overall gain accuracy: ±0.9 dB

Maximum two-level cascading total gain: 60 dB

3. Power and Impedance Parameters

Maximum lossless input power: Positive 30 dBmW

Maximum output power: Positive 25 dBmW

Output impedance: 50 ohms

Harmonic suppression: More than 60 dB carrier

4. Physical and Environmental Parameters

Equipment specification: 3U structure, single slot

Overall power consumption: Multiple power supply, overall power consumption stable and controllable

Operating temperature range: 0 degrees Celsius to 55 degrees Celsius

Cooling method: Chassis forced air cooling

IV. Interface and Communication Configuration

Front panel interface

Fixed gain channel interface: Two sets of SMA interfaces, respectively for signal input and signal output, with an impedance of 50 ohms

Programmable gain channel interface: Two sets of SMA interfaces, respectively for signal input and signal output, with an impedance of 50 ohms

Status indicator lights: Used to display equipment power supply, operation lock, and fault status

Bus and software configuration

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

The accompanying driver program is NI-5690, which can be used in development environments such as LabVIEW, TestStand, Python, and C#.

Supports multi-module clock synchronization and trigger synchronization functions.

V. Core Functions

1. Dual-channel independent amplification design, with one channel being a low-noise fixed gain channel and the other being a wide-range programmable gain channel, capable of adapting to different strengths of RF signals.

2. Wide working frequency band, covering the mainstream RF frequency band from 50 MHz to 8 GHz, with good signal linearity and high purity of the amplified signal.

3. Programmable channels support fine 0.5 dB step adjustment, and also have a direct-through mode, allowing flexible switching of system dynamic range.

4. Strong system expansion capability, when paired with a RF signal analyzer, it can enhance the sensitivity of weak signal detection, and when paired with a RF signal generator, it can enhance the output power.

5. Stable operating state, supporting multi-device synchronous operation, capable of meeting the requirements of large-scale automated RF testing systems.

VI. Application Scenarios

1. Wireless communication testing, used for receiving sensitivity and transmitting power amplification of Bluetooth, wireless local area network, and mobile communication RF modules, etc.

2. RF component testing, completing the gain, loss, and linearity index verification of RF amplifiers, filters, mixers, RF switches, etc.

3. Radar and electronic equipment testing, for amplifying radar signals within 8 GHz, expanding the overall dynamic range of the equipment. 7. Usage and Maintenance Instructions

Installation and Power On

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

After installation, connect the power supply, allow the equipment to preheat for ten minutes, complete the overall machine self-check using the accompanying software, and confirm that the equipment is free of faults.

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.

Wiring and Operation

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

The input power of the equipment should not exceed +30 dBm to avoid hardware damage.

When multiple devices work synchronously, uniformly connect to a 10 MHz reference clock and trigger signal.

Reasonably set the programmable channel gain to avoid excessive gain causing signal overload and waveform distortion.

Daily Maintenance and Calibration

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

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 dust caps on all interfaces.

The equipment storage and usage environment should be free of condensation, with the humidity controlled between 10% and 90%. Keep away from strong electromagnetic interference equipment and 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 vibrations. Do not operate the equipment for a long time in an environment exceeding the rated temperature.