A nightmare for CDMA RF receiver: the cross modulation

Abstract

This paper presents a quantitative analysis on the cross modulation between transmitter CDMA leakage signal and single tone jammer signal, and some design guidelines for overcoming it in receiver design. The analysis shows that duplexer isolation and LNA IIP3 are responsible for the cross modulation. It also shows that LNA IIP3 required for meeting J-STD-018 PCS specification is about 4-5 dBm with duplexer isolation of 50 dB.