Patent ID: 6885261
Filing Date: 2005-04-26
Classification: H01P

Abstract:
1. A dielectric filter comprising: a dielectric block having at least one resonance electrode; a ground electrode on the dielectric block; input and output terminal electrodes to connect the dielectric filter to external circuits; a separated electrode provided on an outer face of the dielectric block, not connected to the input and output terminals or the ground electrode, the separated electrode being connected to the at least one resonance electrode via a capacitance; and a voltage controlled reactance element and a circuit element for controlling the reactance element electrically connected between the separate electrode and the ground electrode, wherein a center frequency of a pass band of the dielectric filter is variable as a result of varying a resonant frequency based on the at least one resonance electrode by varying the capacitance connected to the at least one resonance electrode according to a voltage applied to the voltage controlled reactance element.