FILTER AND HIGH FREQUENCY DEVICE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a frequency variable filter into which a large signal can be inputted by using variable capacitance diodes having paired characteristics and connecting the variable capacitance diodes in series between the signal line of a filter and ground with reversed polarity connection. SOLUTION: The frequency variable filter is constituted of an inductor and a capacitor. In the filter, the capacitor is obtained by connecting the first variable capacitance diode 14 and second variable capacitance diode 15, which have the paired characteristics, in series with reversed polarity. The variable capacitance diodes 14 and 15 and the inductor 13 constitute the variable filter and the variable capacitance diodes 14 and 15 having reversed polarities are connected with reversed polarity. Thus, the miniaturized large signal is inputted to the frequency variable filter and the occurrence of an interference wave can be prevented.