| 摘要 |
PROBLEM TO BE SOLVED: To solve the problems that a component unit price is high for a SAW filter since a piezoelectric body itself is expensive and a fine working technique between electrodes is required and a size is large for a multilayer ceramic filter since a circuit is two-dimensionally formed in an RF band filter used in a radio communication system. SOLUTION: By performing three-dimensional circuit formation for which a plurality of winding wire type microstrip lines 102 are formed as a strip line resonator on the surface layer of a cylindrical dielectric coaxial 101 provided with a ground conductor in the inside, an inexpensive and small-sized RF band filter is realized. COPYRIGHT: (C)2003,JPO |
