1. A radio frequency (RF) communications device comprising: a power amplifier; an antenna; a tunable coupler between said power amplifier and said antenna; a processor; and an exciter module coupled between said processor and said power amplifier and configured to generate an RF signal based upon a baseband signal; said processor configured to set said tunable coupler to a desired tuning and thereby defining a transfer function for said tunable coupler, generate an inverse transfer function of the transfer function of said tunable coupler, and perform digital filtering upstream of said power amplifier based upon the inverse transfer function.