Abstract: A microwave frequency converting receiver of an RF unit should be generally used in wireless/mobile communications systems such as cellular, PCS, WLL and IMT2000 systems and also have low power consumption, low-noise characteristic, high gain and small size.

Abstract: A double balanced active mixer is used for compensating an asymmetric characteristic of complementary radio frequency signals, to thereby improve linearity of the double balanced active mixer. The double balanced active mixer includes an input transistor part for amplifying first and second radio frequency signals having complementary phase each other which are inputted from external circuit and for transferring the amplified first and second radio frequency signals and an Output transistor part for outputting first and second intermediate frequency signals which are complementary each other by switching the amplified first and second radio frequency signals.

Abstract: Disclosed is a method for manufacturing a vertical channel transistor comprising the steps of: selectively implanting a dopant of high concentration into a semiconductor substrate to form a source region; firstly etching the semiconductor substrate using an insulator and a first photoresist pattern as a mask; secondly etching the substrate using a second photoresist pattern having a shape corresponding to said source region as a mask; implanting a dopant of low concentration into the exposed substrate using said second photoresist pattern as a mask to form a vertical channel layer; implanting a dopant of high concentration into the exposed substrate using same mask to form a drain region; activating said dopants, and forming an ohmic contact layer on said drain region; thirdly etching using a third photoresist pattern for exposing the firstly etched portion of the substrate as a mask; depositing a gate metal on the substrate exposed by the thirdly etching; and wiring a metal, respectively.

Abstract: This invention provides infrared sensing photodetector and a method therefor which provides a structure for effectively absorbing a light incident in a normal direction on a substrate, and a method compatible with existing processes for making integrated circuitry.

Abstract: A production method for ion-implanted MESFET having self-aligned LDD structure and T-type gate, that the reverse mesa portion is formed at a predetermined part of the channel region which the source and drain regions are formed at both side by using caps layer, the ion is injected between the source and drain regions and the channel region as the small energy and low concentration by using the reverse mesa as the mask, the source and drain regions of the low concentration is formed so that drain part has more broadly than source part, and the gate electrode and the source and drain regions of the low concentration are not contacted at the formed groove which is removed the surface of the reverse mesa portion or the reverse mesa portion.