National Instruments 778572-44 PXI RF Multiplexer Switch Module
 
The National Instruments 778572-44 (or PXI-2544) is a solid-state 8x1 PXI RF Multiplexer Switch Module. This module features 8 x channels and a single bank. The device is specially designed for RF signal routing. It is equipped with front-mounted SMA connectors that allows hassle-free connection to other RF devices. The FET switch type relay offers the expected mechanical relay life of 1 × 108 cycles and an electrical relay life of up to 2.5 × 106 cycles at lower voltages. This unit has a relay operate time of 1 ms (standard) and 3.3 ms (maximum). This multiplexer module can drive up to 90 relays at the same time.

The input trigger can be sourced from PXI trigger lines 0-7 or the front panel. The minimum pulse width for input trigger is 150 ns. The front panel input voltage ranges from a minimum of -0.5 V to a maximum of 5.5 V along with a nominal value of 3.3 V. Output triggers are also directed to PXI trigger lines 0-7 or the front panel. The programmable pulse widths for output triggers range between 1 µs to 62 µs. The front panel output voltage is 3.3 V TTL at 8 mA.

The 778572-44 multiplexer comes in a compact design (21.6 cm × 2.0 cm × 13.0 cm) and weighs only 538 g. It features 9 x SMA jacks for input/output connections and 2 x SMB jacks for triggers. The module operates with a characteristic impedance of 50 Ω with AC coupling. It also supports a minimum input frequency of 10 MHz. The maximum safe DC input voltage for the module is ±8 V.

The RF performance of this 778572-44 unit is exceptional. The insertion losses at different switch bandwidths are <4.5 dB at ≤2.4 GHz, <6.3 dB at ≤6 GHz, and <7.2 dB at ≤6.6 GHz. The voltage standing wave ratio (VSWR) of this multiplexer remains below 1.9 across most frequencies. To reduce the cross-talk the Channel-to-channel isolation exceeds 77 dB at ≤2.4 GHz. The unit operates within a temperature range of 0 °C to 55 °C and can be stored between -20 °C to 70 °C. The relative humidity tolerance of this unit is 5% to 85%.

This RF multiplexer unit complies with several safety and EMC standards like IEC 61010-1, EN 61010-1, UL 61010-1, and CSA C22.2 No. 61010-1. The 778572-44 is designed for indoor use and can withstand operational shocks up to 30 g peak and random vibrations up to 0.3 g during operation.