Bell Telephone Laboratories

Lucent Technologies Inc.

At&t Bell Laboratories

Other

Ncr Corporation

At+t Corp.

American Telephone & Telegraph Co., At&t Bell Laboratories

Martin V Schneider

James G Evans

Robert W Wilson

Cuong Tran

Ralph Francis Trambarulo

Alfred Yi Cho

Eric R Carlson

Michael J Gans

Bernard Glance

Leonard G Cohen

Arno A Penzias

Lawrence M Drabeck

Richard A Linke

Daniel Lubzens

A disk brake kit including a pair of brake pads disposed on opposite sides of a brake disc and carried from calipers suspended from a kit frame indexed to predetermined land marks on the wheel housing.

High performance retrofit disk brake kit and method of use

A miniature, multi-branch patch antenna suitable for operating in the 1 GHz to 100 GHz frequency range, a method for making same and a communication system using the same is disclosed. In one embodiment, the antenna comprises a planar dielectric substrate, a plurality of conducting antenna elements each having a feed port, a ground plane and a septum located between each conducting antenna element. In a second embodiment, the antenna comprises a planar dielectric substrate, a plurality of conducting antenna elements each having a feed port, a ground plane and a superstrate that is disposed on the plurality of conducting antenna elements and at least a portion of the dielectric substrate. The septum and the superstrate suppress undesirable coupling mechanisms. In a communication system according to the present invention, the miniature, multi-branch patch antenna is coupled to a transmitter and/or receiver.

Miniature multi-branch patch antenna

In an antenna having a conductor of a length L and a dielectric material with a dielectric constant .epsilon..sub.r1 contacting the conductor, a matching dielectric layer .epsilon..sub.r2 less than .epsilon..sub.r1 matches the dielectric constant to free space. Preferably .epsilon..sub.r2 =.sqroot..epsilon..sub.r1 , L=.lambda..sub.o /(2.sqroot..epsilon..sub.r1 ). The depth d of the second dielectric is a quarter wavelength in the matching layer. Multiple matching layers with successively decreasing dielectric constants forms embodiments. In one embodiment the resonant conductive arrangement is a microstrip patch antenna with the dielectric material supporting a patch and matching layer covering the dielectric material.

Small antennas such as microstrip patch antennas

A microstrip patch filter in which a dielectric has a ground plane printed on one of its faces and a conductive arrangement printed on the other of said faces, the conductive arrangement includes a flat patch, input and output leads electromagnetically coupled to the flat patch, the flat patch or the dielectric substrate has a reactance-enhancing metallic constriction located along a portion of the patch. When the constriction is in the patch it forms a current-concentrating inductive constriction. When the constriction is in the dielectric substrate, it enhances the capacitance. In an embodiment, the patch has two mutually-transverse constrictions that divide the patch into four sub-patches cross-connected by current-concentrating inductive constriction.

Microstrip patch filters

A wireless electronic module includes a folded monopole antenna having an antenna port impedance which is reactive at the RF frequency of operation and which conjugately matches the reactive impedance of the electronic circuit which connects to the antenna port. A grounded shield is interposed between the antenna and the electronic circuit to reduce RF losses at the antenna.

Wireless electronic module

In a resonator in which a ground plane and a patch sandwich a dielectric, a slot in the patch concentrates emanation of radiation from the slot. Shorting conductors form the ends of the resonator. A dielectric cover over the slot matches the dielectric constant of the substrate to that of free space. Quarter-wave chokes at the ends of the resonator suppress currents in the ground plane.

Microstrip patch antennas with radiation control

An RF apparatus (e.g., a wireless label) provides improved backscattering of an incident RF signal by utilizing a separate modulator diode, which connects across the antenna, to modulate the backscattering of the antenna. A separate detector diode connects across the antenna through an impedance matching network to detect modulated signals received by the antenna.

Detector and modulator circuits for passive microwave links

The effectiveness of a microstrip conductor antenna, such as a patch antenna, is improved at any particular frequency by making the thickness of the conductor sufficiently small to reduce shielding and losses caused by the skin effect and make currents at the upper and lower surfaces couple with each other and make the conductor partially transparent to radiation. In one embodiment the thickness is between 0.5.delta. and 4.delta.. Preferably the thickness is between 1.delta. and 2.delta. where .delta. is equal to the distance at which current is reduced by 1/e., for example 1.5 to 3 micrometers at 2.5 gigahertz in copper. According to an embodiment, alternate layers of dielectrics and radiation transparent patches on a substrate enhance antenna operation.

High efficiency microstrip antennas

Dielectric components extend between top and bottom surfaces of a ground plane in a resonant microstrip patch antenna over a distance of one-quarter-wavelength of a resonant frequency of the antenna. The components form quarter-wave chokes within which waves cancel with reflected waves and reduce currents in the bottom surfaces of the ground plane. This reduces back lobe responses.

Antennas with means for blocking current in ground planes

A diode detector is integrated into a microstrip patch antenna. Tuning and matching of the detector are accomplished by adjusting the geometry of the patch. Cost, power consumption, losses, and spurious responses are reduced. The antenna may be adapted to a mixer, video detector, i.f. detector, or audio detector.

Microstrip patch antenna with embedded detector

The present invention relates to a high-power solid state amplifier arrangement comprising a large number of solid state amplifiers disposed in a waveguide array. The waveguide array is disposed in the aperture of an antenna feed arrangement at the image plane of an antenna feed to receive a uniform distribution over the array with substantially no spillover. Each of the large number of parallel waveguide sections of the array includes one or more solid state amplifiers in a serial, waveguide-interconnected, arrangement, and a wideband impedance matching arrangement in the waveguide configuration at the input and output of the section.

Space amplifier

The present invention relates to a QPSK modulator or demodulator for modulating two different input bit streams with a subharmonic pump carrier signal to produce an appropriately encoded QPSK output signal. The subharmonic pump carrier signal used is a submultiple of a predetermined microwave or millimeter-wave carrier frequency. The QPSK modulator or demodulator is capable of being fabricated on a planar substrate using appropriate stripline filters and a mixer diode in each of an in-phase and quadrature signal path. A fin line arrangement, also capable of fabrication on the substrate, can be used to introduce an appropriately phased subharmonic pump carrier signal into each of the in-phase and quadrature signal paths before each mixer diode. Each mixer diode mixes the associated data bit stream and one of the two appropriately phased pump carrier signals to produce separate output signals which modulate along separate orthogonal axes, which output signals are combined to produce the QPSK modulator output signal.

QPSK modulator or demodulator using subharmonic pump carrier signals

A metal gate field effect transistor has its source and drain located on one major surface of a gallium arsenide layer, while its gate electrode forms a Schottky barrier contact to an opposed major surface of the layer in a self-aligned relationship to the source and drain.

Method of making self-aligned metal gate field effect transistors

A stripline features high symmetry and promotes uniform current densities to lower losses. The channel (11) of the outer conductor of the stripline has a generally circular cross-section. Opposing lateral grooves (13,14) securely positions a substrate (16) which includes a center conductor. The center conductor features dual metalized strips (17,18) connected together by spaced through-plated holes (19). The stripline is readily formed in a single block of metal and hence eliminates the losses associated with the joint of conventional split-block striplines.

Symmetrical low-loss suspended substrate stripline

The present invention relates to a technique for displacing spurious resonances which are excited in strip transmission line circuits outside the frequency band of interest. Such displacement is accomplished by adding apertures in the capacitive elements of the strip transmission line circuit which have dimensions to move the transverse resonances out of frequency band of interest while causing, for example, no significant change in the passband ripple or the stopband attenuation of a filter. The slots effectively cause the inductance across the capacitive element to increase and, therefore, lower the frequency of the transverse modes or resonances.

Growing community of inventors

Holmdel, NJ, United States of America

Martin V Schneider