Experimental testbed for PA characterization and pre-distortion with relaxed sampling rate requirements

Abstract

This paper explores an interleaving approach to expand the effective sampling rate of analog-to-digital converters (ADCs) with application to power amplifier characterization and digital pre-distortion. By interleaving a known test signal, it is shown that a 250 MSPS ADC can be used to effectively sample at 2 GSPS, providing 1 GHz of observational bandwidth. A 200 MHz “stretched” LTE signal is then acquired using this technique, and digital pre-distortion is successfully applied to an amplifier under test to prove the concept.