Patent ID: 6144260
Filing Date: 2000-11-07
Classification: H03F,H03H

Abstract:
An amplifier having a first filter, which has a desired pass-band and a desired attenuation band and also has a difference between input impedance and output impedance by adjusting the input impedance to a value between 1/2 to 2 times the real part of output impedance of a first transistor and the output impedance to a value between 1/2 to 2 times the real part of input impedance of a second transistor, directly connected between the output terminal of the first transistor and the input terminal of the second transistor,wherein the first filter is formed so as to have electrode patterns built in a dielectric of a relative dielectric constant exceeding 10 inclusive that is sandwiched between ground electrodes on the upper and bottom surfaces thereof, electrode patterns are formed over said ground electrode on the upper surface of said dielectric with a dielectric material of a relative dielectric constant not exceeding 10 placed in between and a first amplification circuit and a second amplification circuit are mounted on said electrode patterns.