| 摘要 |
PROBLEM TO BE SOLVED: To provide a voltage-controlled filter with a minimum mount space whose pass center frequency is controlled wherein a band reject characteristic is attached to a frequency position apart from the pass center frequency by a prescribed frequency. SOLUTION: The voltage-controlled filter whose pass center frequency is controlled is configured by connecting varactor diodes X1, X2 to a coupling circuit comprising microstrip lines MSL1, MSL2 and the MSL1, MSL2 are connected to input output terminals J1, J2 via coupling capacitors C9, C10. Connecting a varactor diode X3 between the MSL1 and the MSL2 to control the capacitance in interlocking with the varactor diodes X1, X2 provides the band reject characteristic at a frequency apart from a center frequency of a VCF (voltage-controlled filter) by an optional frequency. COPYRIGHT: (C)2005,JPO&NCIPI
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