The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 25, 2000
Filed:
Aug. 21, 1998
Chang Hwa Lee, Daejeon, KR;
Myung Soo Kim, Daejeon, KR;
Bon Hee Koo, Daejeon, KR;
Dong Suk Jun, Daejeon, KR;
Sang Seok Lee, Daejeon, KR;
Tae Goo Choy, Daejeon, KR;
Abstract
The present invention relates to a microwave filter, having U-type resonators, which passes a desired frequency signal and removes an undesired frequency signal when used in a high frequency antenna circuit for wireless communication systems. In accordance with the trend of reducing communication system terminals, it is required to reduce a high frequency filter. The high frequency filter is required to attenuate signals very sharply at the stop band especially near to a passband transmitting and receiving frequency, so as to improve the efficiency of the frequency. The filter may be reduced in weight by forming U-type resonators instead of straight-type resonators. Excellent attenuation characteristics may be achieved at the stop band lower than the passband, using the difference of the characteristic impedance between the open end portion and the shorted portion of the resonator by forming the coupling control grooves at the outer walls of the dielectric block.