Patent ID: 8644790

Claim:
An antenna amplifier for an automobile top antenna, the antenna amplifier comprising: an AM signal amplification circuit; an AM frequency selection circuit comprising a capacitor, first and second inductances, and a resistance, the AM frequency selection circuit in circuit with the AM signal amplification circuit; an antenna in circuit with the first inductance in the AM frequency selection circuit through the capacitor, the second inductance is connected to the resistance in parallel, the second inductance comprising a first end in circuit with the first inductance and a second end in circuit with the AM signal amplification circuit; an FM signal amplification circuit; an FM frequency selection circuit in circuit with the FM signal amplification circuit; a power circuit; an AM/FM signal output terminal of a radio receiving antenna in circuit with both the AM frequency selection circuit and the FM frequency selection circuit, signal output terminals of the AM signal amplification circuit and the FM signal amplification circuit in circuit with a shared output plug, a ground terminal of the output plug in circuit with a ground terminal of the antenna amplifier, the power circuit to supply power to the antenna amplifier; and a trap circuit having a first end in circuit with the ground terminal of the antenna amplifier and a second end in circuit with a metal mounting base for the antenna on the automobile, the trap circuit comprising a printed inductance having a first end in circuit with the ground terminal of the antenna amplifier and a second end in circuit with the metal mounting base of the automobile antenna.