Nrd Co., Ltd.

Comotech Corporation

Young Geun Yoo

Young Su Kim

Jae We An

Myoung Yeul Park

Dong Jin Cho

Dong Jin Jo

Disclosed are a waveguide type signal attenuator for attenuating an input signal as desired and a waveguide type signal terminator for making an input signal be utterly disappeared, where a manufacturing-easy resistor sheet is inserted into the center area, along which a traveling electromagnetic wave has the maximum intensity, of the signal attenuator and the signal terminator. In the signal terminator and the signal attenuator, a predetermined part of the waveguide which is formed in a lower conductive plate is expanded out along the half-height plane of the waveguide to form a resistor sheet setting groove and a portion of the elongated cavity positioned behind the resistor sheet setting groove forms a lower half of the waveguide. In addition, a resistor sheet is inserted between the resistor sheet setting groove and a protrusion part which protrudes from an upper conductive plate, of the half-height of the waveguide holds the resistor sheet to form an upper half portion of the waveguide. That is, the resistor sheet installed in the center area of the waveguide can give the desired attenuation or termination of an input signal.

Waveguide type signal terminator and signal attenuator

A non-radiative dielectric (NRD) waveguide modulator is provided having a waveguide type hybrid coupler, in which by forming a waveguide type 180&#xb0; hybrid coupler and waveguide as a single body, the structure is simplified and manufacturing processes are reduced. The NRD waveguide modulator includes a conducting housing having a lower conducting plate and an upper conducting plate; a hybrid coupler which is processed in the form of conduit lines inside the conducting housing and includes a ring portion and a plurality of waveguides extended from the ring portion in the radial direction, in modulator, and a termination which is connected to an isolation port that is an end of any one waveguide of the hybrid coupler and terminates a signal reflected by the modulator by consuming the signal internally.

Non-radiative dielectric waveguide modulator having waveguide type hybrid coupler

Disclosed is a NRD waveguide mixer adopting a ring hybrid coupler applicable to a small-sized and high functional millimeter wave receiving/transmitting device. The NRD waveguide has a housing including two parallel conductive plates. The ring hybrid coupler is installed in the housing and has an annular ring formed with first to fourth ports which are radially extended about the annular ring. An oscillating device is connected to the first port so as to generate a local oscillating signal. A rod antenna is connected to the second port so as to receive/transmit a radio frequency signal. A first balanced mixer mount is connected to the third port and is provided with a first Schottky diode. A second balanced mixer mount is connected to the fourth port and is provided with a second Schottky diode. The radio frequency signal and the oscillating signal inputted from the first and second ports are mixed in the ring hybrid coupler to be transformed into an addition signal and a subtraction signal. The addition and subtraction signals are transmitted to the third and fourth ports to switch the Schottky diodes respectively so that an intermediate signal is generated.

Non-radiative dielectric waveguide mixer using a ring hybrid coupler

Disclosed is a metal window filter assembly, of a millimeter wave band, using an NRD guide. The filter assembly comprises a filter housing including parallel conductive plates and a filter for filtering a certain frequency band of an electromagnetic wave traveling therethrough. The filter includes a plurality of polygonal metal windows and a single body type dielectric line made from a non-radiative dielectric. A plurality of polygonal inserting grooves spaced by the predetermined distance are formed respectively on both surfaces of the dielectric line making contact with the parallel conductive plates. The metal windows are inserted in the inserting grooves one to one to form multi-staged dielectric resonators cascaded as a single body. The filter has a filtering function selectively passing the certain frequency band determined by an impedance coupling relationship that the multi-staged dielectric resonators have with respect to the electromagnetic wave. The filter assembly is suitable for a commercial use due to its simple structure, a small loss and superiority in processing, assembly and productivity.

Metal window filter assembly using non-radiative dielectric waveguide

Disclosed is a local oscillator utilizing an NRD guide applicable to a millimeter wave integrated circuits. A Gunn diode is buried in a bottom of a housing so that a heat generated from the Gunn diode is directly transferred to the housing and is rapidly emitted. Thus, an oscillating power and an oscillating frequency obtained from the local oscillator can be stabilized due to efficient heat-emission. Since a diode mount is not required, manufacturing costs can be reduced while productivity increases. A metal rod resonator, which is easily assembled and has good power and frequency stability as compared with a microstrip resonator, is used as a resonating device. The metal rod resonator is inserted into a fixing block in perpendicular to the NRD guide. An end of the metal rod resonator directly makes contact with an anode of the gun diode. A cavity forming member for defining a cavity, which surrounds main components including the Gunn diode, is installed in the housing. A local oscillator module can be protected and the oscillating power and the oscillating frequency can be stably maintained under a frequency band satisfying a cavity condition.

Growing community of inventors

Ulsan, South Korea

Young Geun Yoo