Electronics and Telecommunications Research Institute

Bon Hee Koo

Sang Seok Lee

Chang Hwa Lee

Dong Suk Jun

Tae Goo Choy

Oh Gon Chun

Meyng Soo Kim

Meyung Soo Kim

Myung Soo Kim

Dong Seok Jeon

O Gon Chun

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

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

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.

Growing community of inventors

Daegu, South Korea

Bon Hee Koo