II. Model Interpretation

PXI: Standard PXI bus, compatible with PXI/PXIe mixed slots.

2798: NI high-frequency RF switch series code, representing 40 GHz, 50Ω, dual-channel conversion (Dual-Transfer), electromechanical relay.

Full name: PXI-2798 40 GHz 50Ω Dual-Transfer Switch Module.

Topology: Dual-Transfer (2 SPDT), each channel contains COM/NO/NC, achieving signal direct connection or switching to DUT.

III. Technical Parameters

(1) RF Core Characteristics

Topology: 2 independent conversion switches (Dual-Transfer) NI

Impedance: 50Ω

Bandwidth: DC～40 GHz

Insertion Loss: ≤1 dB @40 GHz NI

Isolation: ≥60 dB @40 GHz

Return Loss: ≥15 dB @40 GHz

Termination: No built-in termination, 50Ω system matching

(2) Electrical Rated Values

Maximum switching voltage: 30 VAC (cold switch) NI

Maximum current: 0.6 A AC NI

Relay type: Electromechanical Relay (EMR) NI

Action time: ≤5 ms

Mechanical life: 1×10⁶ times (rated load)

Scan rate: 5 times/second NI

(3) Physical and Environmental

Form: Standard 3U PXI single-slot module

Front-end connector: SMA (female) × 6 (each channel COM/NO/NC)

Size: 216 mm × 20 mm × 130 mm

Weight: Approximately 0.45 kg

Power supply: PXI backplane 5 V; typical power consumption 4 W

Operating temperature: 0 ℃～55 ℃

Storage temperature: –20 ℃～70 ℃

Humidity: 5%～85%, no condensation

IV. Interface and Communication Configuration

(1) Front-end I/O Interface

SMA female × 6 (2 independent conversion switches):

Channel 1: COM1 / NO1 / NC1

Channel 2: COM2 / NO2 / NC2

NO: Normally Open (Direct Connection); NC: Normally Closed (Connect to DUT); COM: Common Terminal NI

(2) Bus and Software Communication

Bus interface: Only supports PXIe mixed slots / PXI peripheral slots NI

Driver: NI-SWITCH, compliant with IVI specification

Software support: LabVIEW, TestStand, LabWindows/CVI, Python, C, .NET

Basic functions: NI MAX hardware identification, channel configuration, relay status monitoring, life counting

Trigger capability: Supports PXI backplane Trigger 0～7, multi-module synchronous switching

V. Core Functions

Dual-channel independent conversion switch: Each channel can be independently switched, direct connection (NO) or connecting to DUT (NC), achieving parallel comparison testing of dual channels NI.

40 GHz bandwidth: DC～40 GHz coverage for microwave and millimeter wave, supports harmonic, RF, and high-speed digital signal switching NI.

Low insertion loss + high isolation: 40 GHz insertion loss ≤1 dB, isolation degree ≥60 dB, ensuring signal integrity and reducing crosstalk NI.

Flexible signal path control: One-click bypass / connection to DUT, suitable for device performance comparison, fault troubleshooting, and redundant switching NI.

Relay life monitoring: Built-in counter records the number of on/off times, supports predictive maintenance, reducing downtime risk.

Single-slot high density: 3U PXI single-slot integrates 2 conversion switches, saves cabinet space, suitable for multi-channel RF testing.

VI. Application Scenarios RF Device Comparison Test: Quickly insert/remove amplifiers, filters, mixers in the signal path, and compare performance differences. NI.

5G / Millimeter Wave Equipment Test: Adapt to 5G millimeter wave frequency band with a 40 GHz bandwidth, used for bypass/access testing of base stations, terminals, and RF chips. NI.

Harmonic and High Frequency Signal Routing: Transmit high-order harmonics of RF upconverters on PXI, or route multiple signal sources to downconverters. NI.

Redundancy Switching and System Protection: Automatically bypass when a critical path fails, protecting the back-end instruments and enhancing the reliability of the test system.

Satellite / Aviation Electronics Test: High-frequency signal routing, redundancy switching, adapted to satellite communication, radar, and aviation RF testing requirements. NI.

VIII. Installation and Maintenance Instructions

(1) Installation and Power On

Only install on PXIe mixed slots or PXI peripheral slots. Do not use pure PXIe slots. NI.

Before installation, turn off the power. Fully insert the module and tighten the panel screws.

After powering on, confirm the device identification is normal and there are no errors in NI MAX.

(2) Connection and Operation

Use 50Ω SMA coaxial cable. Ensure the connectors are clean and tightened to avoid signal leakage and reflection.

Cold Switching Operation: Switch the relay when there is no signal to avoid arc damage to the contacts.

Path Configuration: Reset state (default) COM-NC (connect to DUT); Set state COM-NO (direct connection) NI.

Programming Control: Configure channel switching, scanning sequence, and trigger synchronization through NI-SWITCH API.

(3) Maintenance and Lifespan

Regularly read the relay on-off times through NI MAX. Replace when approaching 1×10⁶ times.

Maintain ventilation and heat dissipation. Work temperature ≤ 55 ℃. Avoid accelerating aging due to high temperature.

Avoid overpressure and overcurrent operations to prevent contact oxidation or adhesion.

When not in use for a long time, store in a dry environment (-20 ℃ to 70 ℃), cover the interface with a dust cap.