Nrd Co., Ltd.

Ulsan Chemical Co., Ltd.

Young Su Kim

Young Geun Yoo

Yuichi Iikubo

Dae Hyun Kim

Cheol Ho Kim

Hyang Ja Jang

Jung Eun Lee

Young Gu Cho

The method of preparing a chromium oxide catalyst for preparation of pentafluoroethane using a chloroethane compound includes heat treating chromium hydroxide powder at a temperature not higher than 300&#xb0; C. to obtain chromium oxide powder, heat treating metal hydroxide, at a temperature not higher than 300&#xb0; C. to obtain metal oxide powder, mixing 85&#x2dc;99.5 wt % of the chromium oxide powder with 0.5&#x2dc;15 wt % of the metal oxide powder to obtain a mixture, forming the mixture into a pellet, calcining the pellet at 200-300&#xb0; C. using nitrogen gas, and fluorinating the pellet at 300-320&#xb0; C. using a gas mixture including Nand HF, and then at 320-380&#xb0; C. using HF gas. The fluorination catalyst prepared using the method of this invention can be effectively used to prepare pentafluoroethane at a high yield using a chloroethane compound.

Catalyst for preparation of pentafluoroethane and preparation method thereof

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.

Local oscillator using non-radiative dielectric waveguide

Disclosed is a metal post filter assembly, of a millimeter wave band, using an NRD guide. A filter to which an electromagnetic wave travels is disposed in a filter housing which includes parallel conductive plates facing each other. The filter forms a plurality of inserting holes, by segmenting them into multi-stages, along the length direction of side surface of a dielectric line and parallel to the parallel conductive plates. The filter has a structure that multi-staged dielectric resonators are formed in a single body by inserting metal posts which provide discontinuous surfaces which cause a reflection with respect to the electromagnetic wave in each of the inserting holes. Each impedance of the multi-staged dielectric resonators has an impedance coupling relationship that the impedance becomes gradually and symmetrically smaller to both end stages. According to the impedance coupling relationship, a reflection amount of, and a transmission amount of, the electromagnetic wave traveling along the filter are properly determined. As a result, the filter provides a filtering function which selectively passes only a certain frequency band of 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.

Growing community of inventors

Ulsan, South Korea

Young Su Kim