Magazine Article | August 11, 2017

Improving Accuracy And Throughput In Transmit/Receive Module Testing

By Hiro Maehara, application/VNA expert, Keysight Technologies Inc.

Building an effective test system means overcoming the challenges presented by measurements, signal conditioning and routing, automation, and scalability to respond to future test requirements.

The latest radar systems employ active electrically scanned array (AESA) antennas to provide a faster scan rate, as well as more versatility in detecting and tracking multiple targets across a wider area. Such systems include a transmit/receive (T/R) module for each radiating element, which precisely controls the relative amplitude and phase of signals to concentrate the energy in a desired direction.

A typical T/R module has a power amplifier (PA) in one direction and a low-noise amplifier (LNA) in the other direction. The phase shifter and attenuation adjuster are shared in both directions to send and receive the signal with the same settings. The transmit mode sends a very short pulse radar signal, and then it switches to a receive mode to look for the reflected signals from targets. It repeats this cycle, with different amplitude and phase settings, to rapidly scan wide areas.