II. Model Interpretation

PXI: Standard PXI bus, only compatible with PXIe hybrid slots and PXI peripheral slots NI.

2599: NI high-frequency RF switch series code, representing dual SPDT (Form C) general relays.

Full name: PXI-2599 26.5 GHz 50Ω dual SPDT PXI RF relay module NI.

Topology: Dual independent SPDT (2-SPDT), each group of COM can be switched between NO/NC, supporting signal routing, component insertion / bypass, load switching NI.

III. Technical Parameters

(1) RF Core Characteristics

Frequency range: DC ~ 26.5 GHz (–3 dB) NI

Characteristic impedance: 50 Ω (full channel matching) NI

Insertion loss: Typical <0.3 dB (26.5 GHz); Maximum <0.7 dB

Channel isolation: Typical ≥70 dB (1 GHz); ≥55 dB (26.5 GHz)

VSWR: Typical ≤1.3:1 (26.5 GHz); Maximum ≤1.7:1

Maximum RF power: 150 W (51.76 dBm) / channel (continuous)

Maximum switching voltage: 90 Vrms / 90 VDC NI

Maximum switching current: 1.73 A (resistive) NI

(2) Switch and Relay

Relay type: Electromechanical latch RF relay, gold-plated beryllium copper contacts (Form C)

Channel configuration: Dual SPDT (A: COM1→NO1/NC1; B: COM2→NO2/NC2) NI

Action time: Typical 8 ms; Maximum 15 ms

Mechanical life: 1×10⁷ times (1 V/10 mA)

Electrical life: 2×10⁶ times (150 W/1 GHz)

Termination: Non-terminated, requires external 50Ω terminator

(3) Scanning and Triggering

Scanning list: Maximum 32000 steps programmable list

Full-channel scanning rate: Maximum 2 times/second NI

Trigger channel: PXI backplane Trigger 0~Trigger 7

Minimum trigger pulse width: 150 ns (disable digital filtering)

(4) Physical and Environmental

Form: Standard 3U PXI single-slot module

Front-end connector: 8×SMA (2 groups of SPDT: 2×COM + 2×NO + 2×NC)

Size: 216 mm × 20 mm × 130 mm

Weight: Approximately 0.26 kg

Power supply: PXI backplane 3.3 V/5 V; typical power consumption approximately 3 W

Operating temperature: 0 ℃ ~ 55 ℃

Storage temperature: –20 ℃ ~ 70 ℃

Humidity: 5% ~ 85%, no condensation

IV. Interface and Communication Configuration

(1) Front-end RF Interface (SMA)

Dual SPDT fixed topology (Form C)

Group A: COM1 (common terminal), NO1 (normally open), NC1 (normally closed)

Group B: COM2 (common terminal), NO2 (normally open), NC2 (normally closed)

Connection example

Path switching: Signal source → COM1 → NO1 → DUT; or COM1 → NC1 → load

Component insertion: Signal chain → COM1 → NO1 → filter → NO2 → COM2 → signal chain; switching NC can bypass filter

(2) Bus and Software Communication

Bus interface: PXI backplane, only available for PXIe hybrid slots / PXI peripheral slots NI

Driver: NI-SWITCH, compliant with IVI specification Software support: LabVIEW, TestStand, LabWindows/CVI, Python, C, .NET

Basic functions: Hardware recognition, channel status reading, scan editing, trigger configuration, relay life counting by NI

Synchronization capability: PXI trigger bus enables multi-module high-precision synchronous switching

VII. Core functions

26.5 GHz millimeter-wave wideband switching: covers DC to millimeter-wave, suitable for 5G/6G, satellite communication, radar high-frequency routing by NI.

Dual-channel independent SPDT (Form C): two independent 1×2 switches, supporting signal routing, component insertion / bypass, load switching by NI.

Ultra-low insertion loss + high isolation: 0.3 dB typical insertion loss + 70 dB isolation, ensuring millimeter-wave signal integrity.

150 W high power carrying capacity: single channel 150 W continuous power, meeting high-power RF testing and anti-reflection protection.

Relay life monitoring: onboard counter records on/off times, supporting predictive maintenance, reducing unexpected downtime by NI.

SMA high-reliability connection: standard SMA connector, stable connection, suitable for high-frequency test cables.

VI. Application scenarios

Millimeter-wave communication testing: 5G/6G millimeter-wave modules, satellite communication equipment, radar system signal path switching and component testing by NI.

RF up-conversion chain: PXI RF up-converter high-order harmonic transmission, multi-signal source down-converter routing by NI.

High-power RF testing: power amplifier, high-power amplifier, transmitter testing, path switching and load switching.

General RF testing: signal source, oscilloscope, spectrum analyzer path switching, filter / amplifier insertion / removal by NI.

Semiconductor high-frequency ATE: millimeter-wave RF IC, high-speed digital chip testing system signal routing by NI.

VII. Usage and maintenance instructions

(1) Installation and power-on

Only install in PXIe mixed slots or PXI peripheral slots, do not insert into pure PXIe slots by NI.

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

After powering on, confirm in NI MAX that the device is recognized normally and there are no errors.

(2) Connection and operation

Use 50Ω SMA cables, recommend torque 0.8~1.0 N・m, avoid over-tightening.

For high-power applications (>100 W), the unselected channels must be externally connected with 50Ω load,严禁 open circuit operation to prevent reflection damage to the instrument.

Before switching， confirm that the signal power is within the 150 W rated range to prevent relay contact burnout.

Programming control： Use NI-SWITCH API to configure channels， scan list and trigger.

(3) Maintenance and life

Regularly read the relay on/off times through NI MAX， replace when approaching the life value (mechanical 1×10⁷ / electrical 2×10⁶) in advance by NI.

Maintain ventilation and heat dissipation， do not exceed 55 ℃ working temperature， avoid accelerating aging due to high temperature.

Avoid frequent over-power and over-voltage switching to prevent contact burnout.

When not in use for a long time， store in a dry environment (-20 ℃~70 ℃)， avoid oxidation of contacts due to moisture.