Silicon Laboratories Inc.
System and method of production testing of impedance of radio frequency circuit incorporated on printed circuit board

Abstract:

A test system for testing RF PCBs including an RF probe for interfacing an intermediate node of each RF PCB, an RF source providing an RF test signal, a reflectometer, and a test measurement system that makes a pass/fail determination of each RF PCB using a measured reflection coefficient. Each RF PCB includes an IC matching circuit and an antenna matching circuit coupled between an RFIC and an antenna, in which the intermediate RF node is between the matching circuits. The reflectometer outputs a measured reflection coefficient indicative of a comparison between a reflected RF signal and the RF test signal. The measured reflection coefficient may be corrected using error values based on a calibration procedure using a calibration kit with modified RF PCBs with known loads. The modified RF PCBs are measured with a network analyzer and the test system to calculate the error values used for production testing.