2.
    发明专利
    失效

    公开(公告)号:JPH05347317A

    公开(公告)日:1993-12-27

    申请号:JP34485591

    申请日:1991-12-26

    Abstract: PURPOSE: To improve a resistance characteristic by using a double-layered heat-resistant gate obtained by forming a heat-resistant junction material on the surface of a GaAs substrate and forming a metal having a low resistance on the junction material. CONSTITUTION: N-type impurities 121a are ion-implanted into an active-layer region of a GaAs substrate 121 with the pattern of a photosensitive film 124 as a mask. Next, the photosensitive film 124 is removed, and a silicon layer 122 and a metallic layer 123 are sequentially deposited. Then, a double layer comprising a metal layer 123a and a silicon layer 122a is formed by an etching process. Then, highly concentrated n-type impurities 121b are ion-implanted into a source/drain region, within the active region of the double layer. After the implantation, heat treatment is performed to cause a chemical reaction. By this treatment, a part of the metallic layer 123 in contact with the silicon layer 122 changes into a metallic silicide layer 125. Then, an ohmic electrode 126 is formed, and the device is completed. Thus, the gate has a low resistance.

    POWER AMPLIFIER USED BOTH FOR PORTABLE ANALOG AND DIGITAL TELEPHONE SETS

    公开(公告)号:JPH08186455A

    公开(公告)日:1996-07-16

    申请号:JP31719794

    申请日:1994-12-20

    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.

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