Image Number 3 for United States Patent #6727766.
A dielectric substrate, a transistor, which is an active device, a varactor diode, which is a frequency-variable device, are mounted on one main surface of a package substrate to configure an oscillator. The dielectric substrate is made from a large-dielectric-constant dielectric having high temperature stability. A microstrip-line resonator is formed by thin-film-electrode forming. The microstrip-line resonator and the transistor constitute an oscillating circuit.