A Study on Mixer Measurement Error Based on Vector Network Analyzer

Abstract

For a mixer, its input and output spectrums are very complex. In addition to the signal we want (IF signal), there will be many unwanted signals, such as image(IM) signal, feed through signals, and many higher-order products. If the measurement system is not perfectly matched, these signals will be reflected back and lead measurement errors. Today, taking the advantages of VNA, the mismatch errors caused by RF signal and IF signal can be perfectly removed. However, the errors caused by both IM signal and higher-order products mismatch reconversion (IMHPMRC) are always ignored. These errors have been mentioned in some books and papers, but their levels and influence rules are not discussed. In this paper, a mismatch reconversion model (MRCM) based on X-parameters is proposed to investigate the mixer measurement error caused by IMHPMRC quantitatively. The simulation results show that after totally removed the effects of IMHPMRC using our model, the results are matched with its standard values (SV).