Electronics and Telecommunications Research Institute

Korea Telecommunication Authority

Chang Hwa Lee

Sang Seok Lee

Bon Hee Koo

Dong Suk Jun

Tae Goo Choy

Meyng Soo Kim

Oh Gon Chun

Hee Kyung Sung

Tae Hong Kim

Dong Seok Jeon

Dong Suk Jeon

O Gon Chun

Meyung Soo Kim

Tae Goo Choi

Myung Soo Kim

Suk J Lee

Microwave filter with a movable shield having alignment windows

A duplexer using a dielectric block and having stepped impedance resonators is disclosed. The duplexer comprising open ended resonators arranged in a front side of the dielectric block, shorted resonators arranged in a rear side of the dielectric block, first grooves for controlling receiving coupling at the receiving filter, second grooves for controlling transmitting coupling at the transmitting filter, and a plurality of recesses formed at the bottom of the dielectric block, extending from a first aperture of the open ended resonators to a second aperture of the shorted resonators. The duplexer according to this invention is miniaturized by excluding external elements and has excellent attenuation characteristics, and is being manufactured by simple processes.

Duplexer with stepped impedance resonators

Magnetostatic devices includes: input and output electrodes for including energy conversion pattern provided in a dielectric substrate; a multi-layer -magnetic substance structure placed at an upper portion of the dielectric substrate, wherein magnetically active thin film is placed at both sides of a magnetically inactive substrate; an upper shield, composed of grounded conductor, for preventing the input and output electrodes from coupling; a lower shield provided at the dielectric substrate, wherein the substrate contain a hole with the same length as the upper shield, and walls of said hole are provided with conductor; a magnetostatic wave end portion, inserted into the dielectric substrate to be placed at both end plane of the multi-layer magnetic structure, for blocking the magnetostatic wave not to reflect therefrom; and a magnetostatic wave reflector, provided in the dielectric substrate as a line whose width vary, for reflecting and selecting a desired pass band before it reaches to the magnetostatic wave end portion.

Magnetostatic wave devices for high frequency signal processing

The present invention provides a dielectric filter having a dielectric block, and a plurality of resonators formed within the dielectric block, each of the resonators having a first and second through holes formed vertically through the dielectric block and arranged in series along longitudinal axis of the dielectric block and a coupling portion electrically connecting an end of the first through hole to an end of the second through hole.

Dielectric filter having resonators arranged in series

An HF filter using resonators of a convex-concave structure is capable of easily inserting a serial or parallel capacitance inside the resonators for the sake of a characteristic improvement of frequency at a stop band desired. In the inventive HF filter, an error compensation is simple and a size smallization is available, by utilizing the resonators of the convex-concave structure. Such HF filter consists of a dielectric block having a multitude of grooves formed, in a length direction, on an upper face thereof; a plurality of resonators formed by covering a lowly constant portion of each groove with conductive material, for resonating signals inputted from the outside; a grounding electrode formed on an outer face of the dielectric block and electrically shorted with the PCB; an input electrode for receiving signals from the outside; an output electrode for outputting signals; and a first nonplating part for preventing the input and output electrodes from being electrically shorted with the grounding electrode and realizing a capacitive coupling among the input and output electrodes and its adjacent resonators, thereby being employed in a smallization of a radio communication system and an improvement of a communicative characteristic.

HF filter using resonators having convex-concave structure

An isolator/circulator can keep a size of a 3-way asymmetric propeller resonator and intensity of magnetism, control the preferred frequency, and improve the insertion loss and isolation characteristic due to reducing the ferrite usage region on the maximum, extend the wide band without the external wide band extension, finally to miniaturize, reduce the fabricating cost by means of a simple fabrication. A microstrip/stripline isolator/circulator having a propeller resonator can be used for the device protection and impedance matching of a system and terminal in a transfer communication, personal communication, CT and satellite communication.

Microstripline/stripline isolator/circulator having a propeller resonator

A dielectric resonator includes a dielectric block having an open surface at one of the surfaces thereof, the remaining surfaces being plated with a conductor. The dielectric block has an inner conductor hole formed at a surface of the dielectric block opposite to the open surface, the inner conductor hole extending a predetermined depth toward the open surface such that it does not perforate through the open surface. An electrode pattern is formed on the open surface such that it faces an end surface of the inner conductor hole, the electrode pattern being adapted to provide an input/output capacitor. The dielectric block has a coupling window formed on a predetermined portion of one of the surfaces of the dielectric block, except for the open surface and the surface formed with the inner conductor hole, at a position adjacent to one of the open surface and the surface formed with the inner conductor hole. The coupling window is free of the plated conductor and adapted to control a coupling degree of the resonator to another resonator. Other embodiments include integral type filters having resonators in a single dielectric block.

Dielectric resonator and filter including capacitor electrodes on a

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.

Microwave filter with U-type resonator

A chip type capacitor with a multi-layer structure comprising a plurality of inner electrodes classified into two groups one being used as parts of signal lines and the other being connected to grounded lines. Each of the inner electrodes for radio frequency passages has a pair of inwardly extending recesses adapted to make current flows generated in the inner electrode by radio frequency noise be opposite to each other. Each of at least two grounded inner electrode pairs is interposed between vertically adjacent inner electrodes used as parts of signal lines. The inner electrodes of each pair are connected to ground terminals, respectively, and have a shape formed by removing one protruded grounding portion from a cross shape. With this arrangement, the current flows in the inner electrodes of each pair are opposite to each other, so that electromagnetic fields generated by the current flows through the inner electrodes offset each other, thereby enabling the equivalent serial resistance at radio frequency to be decreased and the inductance to be decreased.

Growing community of inventors

Taejon, South Korea

Chang Hwa Lee