VHF/UHF bidirectional amplifier is a radio frequency signal amplification device used in the very high frequency (30-300MHz) and ultra-high frequency (300MHz-3GHz) frequency bands. Its core working principle is to achieve bidirectional signal enhancement through a combination of low noise amplifier (LNA) and power amplifier (PA). In the receiving link, LNA amplifies weak signals and suppresses noise; In the transmission link, PA increases the output power. Implement transmission and reception isolation through duplexers or switch circuits to avoid signal interference.

VHF/UHF bidirectional amplifiers are mainly used in emergency communication systems such as Tetra, P25, and DMR (for fire protection, public security, and other specialized network systems)，broadcasting and television signal blinding，and ship/aviation mobile communication relay.