Low-cost alternate EVM test for wireless receiver systems

Abstract

In digital radio applications, error-vector-magnitude (EVM) is the primary specification which quantifies the performance of digital modulation implemented in silicon. Production testing of EVM incurs high cost of test instrumentation in automated test equipment (ATE). For EVM testing of wireless receivers, the ATE must include an RF transmitter having (1) the required digital modulation capability, (2) transmitter parameter configurability via test automation software and (3) higher performance and accuracy compared to the receiver-under-test. In this paper, an alternate test methodology for the EVM specification is proposed that eliminates the need for high cost RF sources with digital modulation capability. A sequence of multi-tones generated using low-cost RF sources is used as test stimuli. The EVM specification is computed (predicted) by analyzing the degradation of the test signal by the receiver modules (e.g. LNAs, mixers, filters) by means of the observed waveforms in the baseband. Simulation results are presented.