Pseudo-time domain filter characterization using EVM parameter

In this paper, we propose a new method of filters characterization using the Error Vector Magnitude (EVM) response of a digital modulation in the filter band. This relationship predicts the abnormality in the filter response and provides information on its characteristics (insertion loss, centre frequency, bandwidth). This approach could replace the S-parameters measurements that cost time and money in a production line. We first define EVM with normalization to be available for all modulation types. Then simulations are performed using ADS software from Agilent to calculate the EVM parameter for a QPSK modulation. Finally, measurements are carried out using Vector Signal Analyzer (VSA) for prototype micro-strip band pass filters. The EVM measurements give us first information on the filter response and present good agreement with simulations.