MPA221 is a wideband dual RF amplifier designed to accompany the MTK952 for remote single-frequency transmission. It covers 470–800 MHz with a 330 MHz tunable switching bandwidth and provides up to 2 W on each output or 1 W when the two channels are combined, via a 2:1 integrated power combiner. The unit includes SWR sensing with an automatic output protection loop and Ethernet-based remote monitoring, and is powered from 10–28 V DC through a front‑mounted DB25 connector.