Verification of digital predistortion and estimation of transmitter non-linearity

摘要

A system for verifying digital pre-distortion (DPD) and estimating transmitter (TX) non-linearity has a transmitter path that includes one or more power amplifiers (PAs) coupled to an up-converter. A digital tone generator circuit generates a single tone radio frequency (RF) signal which is applied to a first input of the upconverter to produce a dual tone radio frequency (HF) signal with a second input of the upconverter disabled. A down converter down converts an amplified double tone RF signal to produce an intermediate frequency (IF) double tone signal. A processing block analyzes the IF dual tone signal to estimate signal strengths of one or more intermodulation (IM) product signals.