An automated phase cancellation method for measuring ultra-high third order intercept points

In this paper, we propose an automated third order intercept measurement system that can measure intercept points in the range of 50 to 60 dBm with an output power level of 0dBm per tone. The technique dynamically applies amplitude and phase adjustment to cancel out the main tones which allows for maximum spectrum analyzer sensitivity and the subsequent ability to measure very low level intermodulation tones. The technique automates a lengthy manual procedure thereby dramatically reducing test times while maintaining accuracy.