United States of America As Represented by the Secretary of the Air Force

Other

Tony K Quach

John L Ebel

Kenichi Nakano

James S Sewell

James K Gillespie

Christopher A Bozada

Ross W Dettmer

G David Via

Charles K Havasy

Gregory C DeSalvo

Thomas J Jenkins

Carl I Pettiford

Waleed Khalil

Brian Dupaix

Charles L Cerny

Charles L A Cerny

Gregory C Desalvo

Vipul J Patel

Paul M Watson

Jamin McCue

Matthew LaRue

Wagdy Gaber Mahdi Hussein

Paul D Cassity

Tuan Kim Quach

Yanxia Guo

Aji G Mattamana

Ryan J Welch

Shahriar Rashid

Anders P Walker

A frequency-agile phase modulator with glitch-free multiplexer in CMOS process technologies for applications including wireless communications, radar, automotive radar, etc. Examples herein offer a novel phase modulator architecture that, when combined with either a wideband power amplifier or multiple narrowband amplifiers, allows for a single transmitter to transmit radar, communication, telemetry, or other similar waveforms across multiple frequency bands. The embodiments herein allow one transmitter to cover a very large operating frequency range, resulting in a decrease in size, weight, power consumption, and cost for future 'small' platform systems. In an embodiment, the phase modulator circuit includes a reconfigurable delay-locked loop (DLL) circuit that is configured to receive a radio frequency (RF) input signal (RF) and a configuration signal. The phase modulator circuit also includes a frequency-agile, glitch-free multiplexer circuit configured to receive an oversampled baseband clock signal (clk) and a phase select data input signal.

Frequency agile modulator

A wide-band digital buffer formed in a III-V substrate including a first transistor, a second transistor, a pull-up circuit shifts a t signal to a level of the first transistor. A first capacitor receives the signal, and passes at least a portion of the AC component of the signal to the first transistor. A resistor receives a first bias voltage, and passes it to the first transistor. A pull-down circuit shifts a second signal to a level of the second transistor. A second capacitor receives the second signal, and passes at least a portion of the AC component of the second signal to the second transistor. A second resistor receives a second bias voltage, and passes it to the second transistor.

Wide-band digital buffer driver

An interleaved digital to analog converter (DAC) includes at least a first signal path and a second signal path. The DAC further includes at least a first high speed DAC and a second high speed DAC each having an input and an output. The first signal path and the second signal path are electrically coupled to the first high speed DAC input and the second high speed DAC input, respectively. The DAC also includes a zero phase clock signal supplied to the first high speed DAC and a 180&#xb0; phase shifted clock signal supplied to the second high speed DAC. A summation circuit, having at least two inputs and one output, is coupled to the outputs of the first high speed DAC and the second high speed DACs. A high-pass delta sigma modulator, a low-pass delta sigma modulator, a band pass delta sigma modulator, or notch filter delta sigma modulator is coupled between the first signal path and the first high speed DAC. A second a high-pass delta sigma modulator, a second low-pass delta sigma modulator, a second band pass delta sigma modulator, or a second notch filter delta sigma modulators electrically coupled between the second signal path and the second high speed DAC.

Multi-function reconfigurable delta sigma DAC

U-turn signaling device for vehicles is disclosed, which includes an LED array, and an integrated circuit control circuit which is produces LED activation control signals. These control signals activate the LED array to produce at least three modes of activity including a tail light mode, a turn mode and a U-turn mode in response to activation signals from the tail light, turn signal and U-turn signal respectively. The LED array can be a portable LED array, an embedded LED array or a double-sided LED array. The LED array is a preferably a combo LED array and further includes a monitor screen, which may be mounted in the dashboard of the vehicle, and may include a multi-position turn signal switch. Also disclosed is a flexible U-turn signal device, which may be activated by a wireless remote control switch.

U-turn signal device for motor vehicles

A hybrid integrated circuit fabrication method in which an insulating substrate member and its metallic substrate carrier are made to be mating with precision through use of computer controlled machining performed on each member. A combination of disclosed specifically tailored software and commercially available software are used in the method to generate code for controlling a precision milling machine during the fabrication of substrate and substrate carrier members. The method for precision mating of substrate and substrate carrier enable disposition of a precision recess in the substrate carrier and the location of recess pillars and pedestals (the latter being for integrated circuit die mounting use) at any carrier recess location desirable for electrical, thermal or physical strength reasons. Enhanced electrical thermal and physical properties are achieved in hybrid devices fabricated according to the method especially when compared with devices and methods having the limited availability of comparable elements afforded by previous hybrid fabrication arrangements.

Hybrid electrical circuit method with mated substrate carrier method

An etching based semiconductor wafer thinning arrangement usable as an improved alternative to the usual grinding and polishing wafer thinning. The thinned wafer includes a structurally enhancing wafer backside grid array of original wafer thickness semiconductor material with grid cells surrounding individual thinned wafer areas and serving to improve the strength and physical rigidity characteristics of the thinned wafer. Preferably this grid array is supplemented with an additional, wafer periphery-located, backside ring of semiconductor material also of original wafer thickness. Ability to avoid a wafer front side mounting during thinning accomplishment, fast etching, reduced wafer breakage, enhanced wafer strength and improved wafer handling achieved with the disclosed thinning arrangement all contribute to achieved advantages over conventional wafer thinning. Gallium arsenide or other semiconductor materials are contemplated along with use in radio frequency or other integrated circuit devices of either the single transistor or complete integrated circuit components types.

Stiffened backside fabrication for microwave radio frequency wafers

An integrated circuit substrate via-hole fabrication arrangement providing for accurate determination of via-hole size and via-hole registration through use of a calibrated pattern formed into the integrated circuit substrate during portions of the normal circuit fabrication process. Initiation of the via-hole and fabrication of the calibrated pattern from one surface, such as the front side, of the integrated circuit wafer and completion of the via-hole from the opposite surface of the wafer are contemplated. The calibrated pattern may be one of several possible physical configurations and of selected dimensions usable with the process, materials and circuitry of the device being fabricated. Use of the invention in fabricating ground conductor-connected via conductors for gigahertz radio frequency-capable integrated circuits of the monolithic or mixed hybrid with monolithic type and having a ground plane element is contemplated.

Measured via-hole etching

An enhancement mode periodic table group III-IV semiconductor field-effect transistor complementary pair device is disclosed. The disclosed complementary pair include single metallization for ohmic and Schottky barrier contacts, a permanent non photosensitive passivation layer (a layer which has also been used for masking purposes during fabrication of the device) and gate elements of small dimension and shaped cross section to provide desirable microwave spectrum electrical characteristics. The complementary pair of the invention is fabricated from undoped semiconductor materials disposed in a layered wafer structure and selectively doped by ion implantation to achieve both the p-channel and n-channel transistors. The semiconductor materials may include two, one or zero buffer layers in their layer structure. The disclosed complementary pair is of reduced fabrication cost, increased dimensional accuracy and state of the art electrical performance.

Complementary heterostructure integrated single metal transistor apparatus

A method for fabricating a periodic table group III-IV metal semiconductor metal field-effect enhancement mode complementary transistor pair device is described, a device typically made of gallium arsenide materials. The disclosed fabrication uses initially undoped semiconductor materials, single metallization for ohmic and Schottky barrier contacts, employs a non-alloyed ohmic contact semiconductor layer and includes an inorganic dielectric material layer providing non photosensitive masking at plural points in the fabrication sequence. The invention uses selective ion implantations, and a combined optical and electron beam lithographic process, the latter in small dimension gate areas. These attributes are combined to provide a field-effect transistor complementary pair of reduced fabrication cost, low electrical energy operating requirements increased dimensional accuracy and current state of the art electrical performance. Fabricated device characteristics are also disclosed.

Complementary heterostructure integrated single metal transistor fabrication method

An enhancement mode periodic table group III-IV semiconductor field-effect transistor device is disclosed. The disclosed transistor includes single metallization for ohmic and Schottky barrier contacts, a permanent non photosensitive passivation layer (a layer which has also been used for masking purposes during fabrication of the transistor) and a gate element of small dimension and shaped cross section as needed to provide desirable microwave spectrum electrical characteristics. The transistor of the invention is fabricated from undoped semiconductor materials disposed in a layered wafer structure and selectively doped by ion implantation to achieve either a p-channel or an n-channel transistor. The semiconductor materials may include two, one or zero buffer layers in their layer structure. The disclosed transistor is of reduced fabrication cost, increased dimensional accuracy and state of the art electrical performance.

Single layer integrated metal enhancement mode field-effect transistor

A method for fabricating an enhancement mode periodic table group III-IV metal semiconductor metal field-effect transistor is described. The disclosed fabrication arrangement uses single metallization for ohmic and Schottky barrier contacts, employs initially undoped semiconductor materials--materials selectively doped in a disclosed processing step, employs a non-alloyed ohmic contact semiconductor layer and includes an inorganic dielectric material layer providing non photosensitive masking at plural points in the fabrication sequence along with permanent surface passivation. The invention uses a combined optical and electron beam lithographic process, the latter in small dimension gate areas. These attributes are combined to provide a field-effect transistor capable of microwave frequency use, of reduced fabrication cost, low electrical energy operating requirements increased dimensional accuracy and state of the art electrical performance. Fabricated device characteristics are also disclosed.

Single layer integrated metal process for enhancement mode field-effect

A room temperature wet chemical digital etching technique for, gallium arsenide or other semiconductor material. Hydrogen peroxide and an acid are used in a two step etching cycle to remove the gallium arsenide in approximately 15 .ANG. limited increments. In the first step of the cycle, gallium arsenide is oxidized by, for example, 30% hydrogen peroxide to form an oxide layer that is diffusion limited to a thickness of, for example, 14-17 .ANG. for time periods from 15 seconds to 120 seconds. The second step of the cycle removes this oxide layer with an acid that does not attack unoxidized gallium arsenide. These steps are repeated in succession using new reactant materials and cleaning after each reactant (to prevent reactant contamination) until the desired etch depth is obtained. Experimental results are presented demonstrating the etch rate and process invariability with respect to hydrogen peroxide and acid exposure times. A method for using a Hall effect measurement to determine the achieved change in surface layer thickness of doped semiconductor material is also included.

Digital wet etching of semiconductor materials

A method for fabricating a periodic table group III-IV HEMT/pHEMT field-effect transistor device. The disclosed fabrication arrangement uses a single metalization for ohmic and Schottky barrier contacts, employs selective etching with a permanent etch stop layer, employs a non-alloyed ohmic contact semiconductor layer and includes a permanent non-photosensitive secondary mask element. The invention includes provisions for both an all optical lithographic process and a combined optical and electron beam lithographic process These concepts are combined to provide a field-effect transistor device of reduced fabrication cost, increased dimensional accuracy and state of the art electrical performance.

Single layer integrated metal process for high electron mobility

A method for fabricating a periodic table group III-IV field-effect transistor device is described. The disclosed fabrication arrangement uses a single metallization for ohmic and Schottky barrier contacts, employs selective etching with a permanent etch stop layer, employs a non-alloyed ohmic contact semiconductor layer and includes a permanent semiconductor material secondary mask element, a mask element which can be grown epitaxially during wafer fabrication. The invention includes provisions for both an all optical lithographic process and a combined optical and electron beam lithographic process These concepts are combined to provide a field-effect transistor device of reduced fabrication cost, increased dimensional accuracy and state of the art electrical performance.

Field effect transistor process with semiconductor mask, single layer

A method for fabricating a periodic table group III-IV metal semiconductor metal field-effect transistor device is described. The disclosed fabrication arrangement uses a single metalization for ohmic and Schottky barrier contacts, employs selective etching with a permanent etch stop layer, employs a non-alloyed ohmic contact semiconductor layer and includes a permanent non photosensitive secondary mask element. The invention includes provisions for both an all optical lithographic process and a combined optical and electron beam lithographic process. These concepts are combined to provide a field-effect transistor device of reduced fabrication cost, increased dimensional accuracy and state-of-the-art electrical performance.

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Kettering, OH, United States of America

Tony K Quach