Enabling GSM/GPRS/EDGE EVM testing on low cost multi-site testers

Abstract

The key motivation for this work is to enable the use of low cost multi-site testers that exhibit both high transmit test stability and high throughput suitable for massive production of a 2/2.75G GSM/EDGE multi-mode cellular single-chip radio. Due to stringent performance compliance test requirements, transmitter (TX) testing consumes more time on expensive automated test equipment (ATE) and therefore it is critical to develop cost efficient multi-site test schemes, which can exploit parallelism to achieve production testing cost goals. This paper illustrates our low-cost self-contained test methods for both GSM phase trajectory error (PTE) and EDGE TX error vector magnitude (EVM) testing in a TX. We compare our test results with those of the R&S vector signal analyzer (VSA) to demonstrate the achieved test accuracy. Current production solutions allow us to simultaneously test and process up to eight devices using multi-site hardware with eight ATE RF receiver cores. Through scaling and careful hardware/software co-design we are able to realize a sixteen site solution using a combination of serial capture and parallel processing scheme.