Technique to eliminate RF signal amplitude dependence in AOA measurement

Abstract

A technique to estimate an incoming radio frequency (RF) signal angle of arrival (AOA) irrespective of the RF signal amplitude is presented. It is based on measuring the DC voltage at the output of two modules where each of them consists of an optical modulator, an optical filter and a photodetector. An RF signal amplitude-independent AOA can be obtained from the ratio of the two DC voltages. Experimental results are presented that demonstrate 0°-63°AOA measurement with <3°errors for an RF signal with three different power levels of 3.2, −0.3 and −3.6 dBm into the modulator.