Patents Assigned to Microwave Technology, Inc.
  • Patent number: 5321283
    Abstract: The junction field effect transistors (JFETs) of this invention have improved breakdown voltage capability, reduced on-resistance and improved overdrive capability. The JFET on-resistance is decreased by ion-implanting an insulating layer covering a layer that contains the source and gate regions of the unipolar transistor. The charge of the implanted ions is the same as the charge polarity of the gate regions. To improve the overdrive capability of a JFET a region of conductivity opposite to the conductivity of the gate region is formed in the gate region of the transistor. This region of opposite conductivity creates another junction within the gate region i.e., the junction between the region of opposite conductivity and the gate region, and the junction between the gate region and the layer containing the gate region.
    Type: Grant
    Filed: July 30, 1991
    Date of Patent: June 14, 1994
    Assignee: MicroWave Technology, Inc.
    Inventors: Adrian I. Cogan, Neill R. Thornton
  • Patent number: 5087959
    Abstract: A protective coating useful as a passivation layer for semiconductor devices incorporates a thin film of an amorphous diamond-like carbon. In one implementation, a thin film of amorphous silicon is deposited over the carbon material. The semiconductive passivation coating prevents electrical shorts, dissipates charge build-up and protects against chemical contamination.
    Type: Grant
    Filed: March 2, 1988
    Date of Patent: February 11, 1992
    Assignee: Microwave Technology, Inc.
    Inventors: Masahiro Omori, Edward B. Stoneham
  • Patent number: 4972250
    Abstract: A protective coating useful as a passivation layer for semiconductor devices incorporates a thin film of an amorphous diamond-like carbon. In one implementation, a thin film of amorphous silicon is deposited over the carbon material. The semiconductive passivation coating eliminates electrical shorts, dissipates charge build-up and protects against chemical contamination.
    Type: Grant
    Filed: March 2, 1987
    Date of Patent: November 20, 1990
    Assignee: Microwave Technology, Inc.
    Inventors: Masahiro Omori, Edward B. Stoneham
  • Patent number: 4788156
    Abstract: One embodiment of a process in accordance with our invention includes the step of forming a P type region on a semiconductor substrate. After the P type region is formed, an N type layer is epitaxially grown on the P type region. A Schottky gate is then formed on the N type epitaxial layer. A first portion of the epitaxial layer serves as a transistor source, a second portion of the epitaxial layer serves as the transistor drain, and a third portion of the epitaxial layer serves as the channel. Of importance, the P type semiconductor region helps prevent various short channel effects caused when current carriers flowing between the source and drain flow too far from the Schottky gate.
    Type: Grant
    Filed: September 24, 1986
    Date of Patent: November 29, 1988
    Assignee: Microwave Technology, Inc.
    Inventors: Edward B. Stoneham, Masahiro Omori, Arthur D. Herbig
  • Patent number: 4768005
    Abstract: A DC bias line module for use with an r.f. signal processing apparatus which incorporates terminating resistors, in lieu of capacitors, that are connected to the r.f. line.
    Type: Grant
    Filed: March 25, 1987
    Date of Patent: August 30, 1988
    Assignee: Microwave Technology, Inc.
    Inventor: Kenneth N. Kawakami
  • Patent number: 4677391
    Abstract: A series biasing arrangement for a pair of junction field effect transistors (JFETs), which may be used in RF amplifiers, mixers or oscillators, comprises connecting the JFETs together in series, with the gates of the two JFETs selectively connected to different reference potentials. The first FET is also connected to the DC voltage source. In one embodiment of the invention, two operational amplifiers, whose output leads are connected to the gates of corresponding JFETs have their noninverting input leads connected to selected points on a voltage divider made up of three resistors and their inverting input leads each connected to the source of a corresponding JFET. The drain to source voltage drops across the JFETs are controlled solely by the values of two of the resistors in the three resistor voltage divider. The bias current through the series-connected JFETs can be controlled independently of the drain to source voltage drops across each of the JFETs.
    Type: Grant
    Filed: May 9, 1986
    Date of Patent: June 30, 1987
    Assignee: Microwave Technology, Inc.
    Inventor: Kenneth Kawakami
  • Patent number: 4596959
    Abstract: A series biasing arrangement for a pair of junction field effect transistors (JFETs), which may be used in RF amplifiers, mixers or oscillators, comprises connecting the JFETs together in series, with the gates of the two JFETs selectively connected to different reference potentials. The first FET is also connected to the DC voltage source. In one embodiment of the invention, two operational amplifiers, whose output leads are connected to the gates of corresponding JFETs have their noninverting input leads connected to selected points on a voltage divider made up of three resistors and their inverting input leads each connected to the source of a corresponding JFET. The drain to source voltage drops across the JFETs are controlled solely by the values of two of the resistors in the three resistor voltage divider. The bias current through the series-connected JFETs can be controlled independently of the drain to source voltage drops across each of the JFETs. The two FETs need not be closely matched.
    Type: Grant
    Filed: November 23, 1984
    Date of Patent: June 24, 1986
    Assignee: Microwave Technology, Inc.
    Inventor: Kenneth Kawakami