| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a tunable high-frequency band pass filter that is easy to be manufactured, low in cost, low in loss, narrow in band, small in size, and that can change a pass center frequency arbitrarily. <P>SOLUTION: Resonators constituted by two hairpin-like microstrip lines on a high-frequency circuit substrate are arranged so that open ends of those are opposed to each other at a predetermined interval. A relationship between two lengths from a connection position of an input line electrically connected to the input side resonator to both open ends of the input side resonator, and two lengths from a connection position of an output line electrically connected to the output side resonator to both open ends of the output side resonator, is set to be complementary. Lengths of the two microstrip lines from the connection position with the input line to the connection position with the output line are equalized. The open ends are electrically coupled to generate two matching frequencies between two attenuation frequencies and obtain a band pass characteristic. Capacitive loads are provided at the respective connection positions of the input and output lines, and a value of the pass center frequency is controlled by a capacitance value of the capacitive loads. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
