PURPOSE: To contrive to attain the miniaturization by connecting a varactor diode between an inner conductor and an outer conductor of a dielectric resona tor on the open end face side of the said dielectric coaxial resonator so as to decrease number of stages of the titled filter.
CONSTITUTION: The dielectric coaxial resonator 10 is firmed by a cylindrical dielectric 11 made of a high dielectric material such as a TiO2 ceramic coated with the outer conductor 12 and the inner conductor 13, the one end is formed as a short-circuit end and the other end is an open end. The anode of the varactor diode D is connected to the outer conductor 12 and the cathode is connected to the inner conductor 13 respectively at the open end. The cathode of the varactor diode D is connected to a variable voltage source E via a coil L for AC blocking. That is, the dielectric coaxial resonator 10 is represented as the parallel connection between an inductance L0 and a capacitance C0 and the varactor diode D is represented as a variable capacitance VC connected in parallel with the inductance L0 and the capacitance C0.
YAMASHITA SADAO
TSUNODA KIKUO
HIRATSUKA TOSHIRO
MIYAWAKI KAZUYOSHI
| JPS5257701A | 1977-05-12 |