HIGH-FREQUENCY FILTER DEVICE

PROBLEM TO BE SOLVED: To provide a high-frequency filter device which is structured of dielectric substrates, and has a low loss and an attenuation pole. SOLUTION: The high-frequency filter device includes laminated dielectric layers 1 and 2 and conductor layers 4 and 5, a plurality of shielding via conductors 8, termination via conductors 9, waveguides 12, strip conductors 6 and 7, and an input and output joint via conductor 10. Each of the plurality of shielding via conductors 8 is formed so that the conductor layers 4 and 5 may be short-circuited. The plurality of shielding via conductors 8 are arranged in two columns with mutual spacing of 1/2 signal wavelength or less and column spacing of 1/2 signal wavelength or more. The waveguides 12 are surrounded by the shielding via conductors 8 of two columns and the termination via conductors 9. The strip conductors 6 and 7 are formed on the surface of the dielectric layer 2. The input and output joint via conductor 10 is located in the waveguide 12 between the termination via conductors 9. One end of the input and output joint via conductor 10 is connected to the strip conductors 6 and 7 respectively through a penetrated hole 11 formed at the conductor layer 4, and the other end is connected to the waveguide 12. The resonance mode is excited at two waveguides 12-2 and 12-3 surrounded by the input and output joint via conductor 10, the termination via conductors 9, and the shielding via conductors 8 to produce the attenuation pole. COPYRIGHT: (C)2010,JPO&INPIT