Patents Assigned to Microwave Technology, Inc.
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Patent number: 5321283Abstract: 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: GrantFiled: July 30, 1991Date of Patent: June 14, 1994Assignee: MicroWave Technology, Inc.Inventors: Adrian I. Cogan, Neill R. Thornton
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Patent number: 5087959Abstract: 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: GrantFiled: March 2, 1988Date of Patent: February 11, 1992Assignee: Microwave Technology, Inc.Inventors: Masahiro Omori, Edward B. Stoneham
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Patent number: 4972250Abstract: 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: GrantFiled: March 2, 1987Date of Patent: November 20, 1990Assignee: Microwave Technology, Inc.Inventors: Masahiro Omori, Edward B. Stoneham
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Patent number: 4788156Abstract: 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: GrantFiled: September 24, 1986Date of Patent: November 29, 1988Assignee: Microwave Technology, Inc.Inventors: Edward B. Stoneham, Masahiro Omori, Arthur D. Herbig
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Patent number: 4768005Abstract: 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: GrantFiled: March 25, 1987Date of Patent: August 30, 1988Assignee: Microwave Technology, Inc.Inventor: Kenneth N. Kawakami
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Patent number: 4677391Abstract: 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: GrantFiled: May 9, 1986Date of Patent: June 30, 1987Assignee: Microwave Technology, Inc.Inventor: Kenneth Kawakami
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Patent number: 4596959Abstract: 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: GrantFiled: November 23, 1984Date of Patent: June 24, 1986Assignee: Microwave Technology, Inc.Inventor: Kenneth Kawakami