公开(公告)号：JPH0845965A

公开(公告)日：1996-02-16

申请号：JP11756695

申请日：1995-05-16

Applicant: KOREA ELECTRONICS TELECOMM

Inventor： RI SHIYOURAN ,  KIN KAISEN ,  BUN SAIKIYOU ,  BOKU KIYOUBO

IPC: H01L29/812 ,  H01L21/338 ,  H01L21/76 ,  H01L21/8252 ,  H01L29/10 ,  H01L29/45

Abstract: PURPOSE: To make it possible to prevent flowing of a parasitic carrier in an interface between a substrate and a buffer layer into a channel layer. CONSTITUTION: First GaAs buffer layer 10A without being doped is formed on a semi-insulation GaAs substrate 70, a superlattice layer 80 is formed on the first GaAs buffer layer 10A, the second GaAs buffer layer 10B made of the same material as the first GaAs buffer layer is formed on the superlattice layer 80 without being doped, a channel layer 20 is formed on the second GaAs buffer layer 10B, and a surface protection film 30 is formed on the channel layer 20.

公开(公告)号：JPH08186455A

公开(公告)日：1996-07-16

申请号：JP31719794

申请日：1994-12-20

Applicant: KOREA ELECTRONICS TELECOMM

Inventor： MOU SEIZAI ,  RI MASASUZU ,  BOKU KIYOUBO

IPC: H03F3/60 ,  H03F3/189 ,  H03F3/20 ,  H03F3/24 ,  H04B1/3822 ,  H04B1/40

Abstract: PURPOSE: To obtain a power amplifier that is used for all analog communication and digital communication systems operated at a low power supply voltage. CONSTITUTION: Microstrip lines L1-L10 each having a characteristic impedance of 50 ohms and a variable capacitor are used to adjust a gate bias by analog and digital methods. After obtaining an impedance at each terminal, an output terminal that is in matching with a major frequency and has a low impedance of 2 ohms or below with respect to second and third harmonics is configured. Through the configuration above, the power amplifier is used for analog and digital communication systems by keeping the linearity and attaining a high efficiency characteristic.

公开(公告)号：JPH08186454A

公开(公告)日：1996-07-16

申请号：JP31719694

申请日：1994-12-20

Applicant: KOREA ELECTRONICS TELECOMM

Inventor： KOU INGABU ,  KIN BINKEN ,  KIN CHIYUUKAN ,  RI MASASUZU ,  BOKU KIYOUBO

IPC: H03F3/60 ,  H01P5/02 ,  H03F3/193

Abstract: PURPOSE: To obtain excellent stability over all frequency bands by overcoming deteriorated stability due to an inductive component of a bonding wire connected externally. CONSTITUTION: In the case that grounding points are unified into one node and connected externally by using a bonding wire 120 in the low noise amplifier having an input matching section consisting of capacitors 101, 102 and an inductor 103 and an output matching section consisting of two MESFETs 104, 113 connected in cascade and a capacitor 117, a capacitor 110 is connected in parallel between the MESFETs 104, 113 to improve the deteriorated stability.