Present invention relates to hand held telephone system base station amplifier. It features including coupler, four low noise amplifier and high linear power amplifier, said coupler is four port coupler consisting of four loop unit and two three- db bridge. Said invention can reduce system noise figure from more than 3.5 db drop to lower than 1.6 db with more than 30 db gain, thereby to raise base station receiving sensitivity and solve up-down balanceless after large power overlay by PHS network. |