Patent ID: 7853232

Claim:
A low-noise amplifier for amplifying an input signal to produce an amplified signal, comprising: an input matching circuit supplied with said input signal to produce a matched signal, said input matching circuit comprising a capacitor and at least one inductor, said capacitor and said at least one inductor having predetermined capacitance and inductance values so as to form a filter having a low-side cutoff frequency near a pass band intended for use on its low-frequency side, thereby cutting off frequencies lower than the low-side cutoff frequency; an impedance conversion portion, supplied with the matched signal, for achieving impedance matching with an output of an antenna to produce a converted signal; and a low-noise amplification portion for amplifying the converted signal to produce the amplified signal, wherein said input matching circuit serves as a band-pass filter having a high-side cutoff frequency near the pass band on its high-frequency side.