Analysis and Measurement Of Self Mixing Of Transmitter Leakage in WCDMA Receivers

In this paper we analyze and measure the distortion due to self-mixing of transmitter (TX) leakage in WCDMA mobile receivers (RX). The self-mixing is primarily due to the second order non linearity of the mixer, which is very significant in WCDMA receivers due to the high power of the TX leakage signal. Existing published work has analyzed the dependence of this distortion, on the TX leakage power and second order non-linearity of the mixer. We go one step further and derive closed form expression for this distortion as a function of the power level of the TX, the second order nonlinearity of the mixer, and the number of equal power WCDMA channels in the TX leakage signal. This is also verified against measurements on a WCDMA receiver Chip