Rockwell Scientific Licensing LLC

Innovative Technology Licensing LLC

Teledyne Licensing, LLC

Rockwell International Corporation

John A Higgins

Berinder P S Brar

James Chingwei Li

Richard L Pierson, Jr

Jonathan Bruce Hacker

Moonil Kim

Hao Xin

Sam K Buchmeyer

Richard L Kaiser

Glenn R Doughty

A variable IC capacitor includes a semiconductor layer doped to contain mobile charge carriers. Capacitor electrodes Cand Care disposed adjacent to each other on the layer's surface, gate electrodes Gand Gare disposed on opposite sides of Cand C, and source and sink electrodes are disposed on opposite sides of Gand G. Potentials are applied to the electrodes as needed to inject and then confine a finite charge into the region under Cand C. A drive voltage V applied between Cand Ccauses the charge packet to move back and forth beneath them, such that the effective capacitance C seen by drive voltage V is given by C=Q/V, where Q is the magnitude of the charge packet.

Variable charge packet integrated circuit capacitor

A method for fabricating an HBT is disclosed, wherein successive emitter, base, collector and sub-collector epitaxial layers are deposited on a substrate, with the substrate being adjacent to the sub-collector layer. The epitaxial layers are etched to provide locations for contact metals and emitter, base and contact metals are deposited on the emitter, base and sub-collector epitaxial layers, respectively. A self-alignment material is deposited on the surface of the substrate around the epitaxial layers and a planarization material is deposited on and covers the top surface of the HBT. The planarization material is then etched so it has a planar surface about the same level as the surface of the self-alignment material and the contact metals protrude from the planar surface. The planar metals are then deposited over the protruding portions of the contact metals.

Heterojunction bipolar transistor with dielectric assisted planarized contacts and method for fabricating

A waveguide is disclosed that shifts the phase of the signal passing through it. In one embodiment, the waveguide has an impedance structure on its walls that resonates at a frequency lower than the frequency of the signal passing through the waveguide. This causes the structure to present a capacitive impedance to the signal, increasing its propagation constant and shifting its phase. Another embodiment of the new waveguide has impedance structures on its wall that are voltage controlled to change the frequency at which the impedance structures resonate. The range of frequencies at which the structure can resonate is below the frequency of the signal passing through the waveguide. This allows the waveguide cause a adjust the shift in the phase of its signal. An amplifier array can be included in the waveguides to amplify the signal. A module can be constructed of the new waveguides and placed in the path of a millimeter beam. A portion of the beam passes through the waveguides and the beam can be shifted or steered depending on the phase shift through each waveguide.

Phase shifting waveguide with alterable impedance walls

A filter includes a waveguide with at least one impedance structure with a resonant frequency. The impedance structure is positioned in the waveguide to reflect signals at the resonant frequency. The filter can be tunable by including variable capacitance devices in the impedance structure(s) so that the resonant frequency can be adjusted.

Waveguide band-stop filter

A tunable filter includes a waveguide with at least one resonant cavity and a tunable impedance structure coupled to each resonant cavity. Each resonant cavity has a resonant frequency and its corresponding impedance structure can be tuned to adjust the resonant frequency. The filter transmits the signal in a pass-band that includes the resonant frequency and reflects signals outside the pass-band.

Tunable waveguide filter

Phase shifting waveguide and module utilizing the waveguides for beam phase shifting and steering

A shutter switch is disclosed and placed in the path of a millimeter beam and is either opaque or transparent to the beam. The shutter switch comprises a number of waveguides placed adjacent to one another to intercept the beam, a portion of the beam passing through each waveguide. The dimensions of each waveguide are such that transmission of the respective portion of the beam would be cut-off if all of the waveguide walls were conductive. However, the waveguides have high impedance structures on at least two of their opposing interior walls that allow the beam at the design frequency to be transmitted through the waveguide with uniform density and minimal attenuation. At this design frequency the shutter switch is essentially transparent to the beam. Each of the high impedance structures can also be changed to a conductive surfaces such that all of the waveguide walls appear conductive and the waveguide takes on the characteristics of a metal rectangular waveguide. In this state transmission through each waveguide is cut-off and the shutter switch blocks transmission of the beam. The shutter switch can change states from blocking to transparent in microseconds or less while consuming very little power.

Shutter switch for millimeter wave beams and method for switching

Test probe pads are located lateral to, and spaced from, the emitter, base or collector region of a bipolar transistor, preferably on separate pedestals, and connected to their respective transistor regions by air bridges. The probe pads, transistor contacts and air bridges are preferably formed as common metallizations. In the case of an HBT, a gap in the subcollector below the air bridges insulates the test transistor from capacitor loading by the probe pads. The test transistors can be used to characterize both themselves and functional circuit transistors fabricated with the same process on the same wafer by testing at an intermediate stage of manufacture, thus allowing wafers to be discarded without completing the manufacture if their transistors do not meet specifications.

Bipolar transistor test structure with lateral test probe pads

A heterojunction bipolar transistor (HBT) is disclosed that includes successive emitter, base and collector and sub-collector epitaxial layers and emitter, base and collector contact metals contacting the emitter, base and sub-collector layers respectively. A passivation material is included that covers the uncovered portions of the layers and covers substantially all of the contact metals. The passivation material has a planar surface and a portion of each of the contact metals protrudes from the surface. Planar metals are included on the planar surface, each being isolated from the others and in electrical contact with a respective contact metal. A method for fabricating an HBT is also disclosed, wherein successive emitter, base, collector and sub-collector epitaxial layers are deposited on a substrate, with the substrate being adjacent to the sub-collector layer. The epitaxial layers are etched to provide locations for contact metals and emitter, base and contact metals are deposited on the emitter, base and sub-collector epitaxial layers, respectively. A self-alignment material is deposited on the surface of the substrate around the epitaxial layers and a planarization material is deposited on and covers the top surface of the HBT. The planarization material is then etched so it has a planar surface about the same level as the surface of the self-alignment material and the contact metals protrude from the planar surface. The planar metals are then deposited over the protruding portions of the contact metals.

A multi layered high impedance structure presents a high impedance to multiple frequency signals, with a different frequency for each layer. Each layer comprises a dielectric substrate, and an array of radiating elements such as parallel conductive strips or conductive patches on the substrate's top surface, with a conductive layer on the bottom surface of the bottommost layer. The radiating elements of succeeding layers are vertically aligned with conductive vias extending through the substrates to connect the radiating elements to the ground plane. Each layer presents as a series of parallel resonant L-C circuits to an E field at a particular signal frequency, resulting in a high impedance surface at that frequency. The new structure can be used as the substrate for a microstrip patch antenna to provide an optimal electrical distance between the resonator and backplane at multiple frequencies. It can also be used in waveguides that transmit multiple signal frequencies signals in one polarization or that are cross-polarized. As a waveguide it maintains a near-uniform density E and H fields, resulting in near uniform signal power density across the waveguide's cross-section.

High impedance structures for multifrequency antennas and waveguides

A bipolar junction transistor (BJT) requires the fabrication of a BJT structure and of a support post which is adjacent to, but physically and electrically isolated from, the BJT structure. The BJT structure includes a semi-insulating substrate, a subcollector, a collector, a base, and an emitter. Metal contacts are formed on the subcollector and emitter to provide collector and emitter terminals. Contact to the structure's base is accomplished with a metal contact which extends from the top of the support post to the edge of the base nearest the support post. The contact bridges the physical and electrical separation between the support post and the base and provides a base terminal for the device. The base contact need extend over the edge of the base by no more than the transfer length associated with the fabrication process. This results in the smaller base contact area over the collector than would otherwise be necessary, and a consequent reduction in base-collector capacitance. The invention is particularly useful when forming heterojunction bipolar transistors (HBTs), built on a compound semiconductor substrate such as indium phosphide (InP).

Mechanically-stable BJT with reduced base-collector capacitance

A BJT device configuration includes an emitter finger and via arrangement which reduces emitter finger width, and is particularly suitable for use with compound semiconductor-based devices. Each emitter finger includes a cross-shaped metal contact which provides an emitter contact; each contact comprises two perpendicular arms which intersect at a central area. A via through an interlevel dielectric layer provides access to the emitter contact; the via is square-shaped, centered over the center point of the central area, and oriented at a 45&#xb0; angle to the arms. This allows the via size to be equal to or greater than the minimum process dimension, while allowing the width of the emitter finger to be as narrow as possible with the alignment tolerances still being met.

BJT device configuration and fabrication method with reduced emitter width

A thin InGaAs contact layer is provided for the collector of a heterojunction bipolar transistor (HBT) above an InP sub-collector. The contact layer provides a low resistance contact mechanism and a high thermal conductivity path for removing device heat though the sub-collector, and also serves as an etch stop to protect the sub-collector during device fabrication. A portion of the sub-collector lateral to the remainder of the HBT is rendered electrically insulative, preferably by an ion implant, to provide electrical isolation for the device and improve its planarity by avoiding etching through the sub-collector.

Method of fabricating a bipolar transistor

Heterojunction bipolar transistor with InGaAs contact and etch stop layer for InP sub-collector

A shutter switch is disclosed the is placed in the path of a millimeter beam and is either opaque or transparent to the beam. The shutter switch comprises a number of waveguides placed adjacent to one another to intercept the beam, a portion of the beam passing through each waveguide. The dimensions of each waveguide are such that transmission of the respective portion of the beam would be cut-off if the all of the waveguide walls were conductive. However, the waveguides have high impedance structures on at least two of their opposing interior walls that allow the beam at the design frequency to be transmitted through the waveguide with uniform density and minimal attenuation. At this design frequency the shutter switch to be essentially transparent to the beam. The high impedance structures can also be changed to a conductive surfaces such that all of the waveguides walls appear conductive and the waveguide takes on the characteristics of a metal rectangular waveguide. In this state transmission through each waveguide is cut-off and the shutter switch blocks transmission of the beam. The shutter switch can change states from blocking to transparent in microseconds or less while consuming very little power.

Growing community of inventors

Westlake Village, CA, United States of America

John A Higgins