Southern Methodist University

US Government As Represented by the Secretary of the Army

Other

Texas Instruments Corporation

USA As Represented by Secretary of the Navy

Choon Sae Lee

Vahakn Nalbandian

Yang Fan

Felix Schwering

James Minh Tran

Daivd A Willis

Guang Yang

Guan-Guo Cheng

A phase shifter that relies on a reflected wave from a load such as a varactor with a capacitance varied by an external bias voltage is provided. The phase shift does not depend on the wave propagation through an active medium. The input RF signal is sent to the variable loading and the reflected wave from the load is channeled to the output port via a network that takes the input signal without much reflection to the input terminal but passes most of the power from the variable load to the output terminal with a phase change depending on the variable bias input of the loading. Such network to steer the input to the variable loading and send the signal reflected from the loading to the output port without much reflection includes a quadrature hybrid or a circulator.

Phase shifter and electronic switch

A system for electromagnetically transferring heat from one region to another region. To cool one region in a chamber, antennas in the chamber to be cooled preferably have a broad beam to collect thermal radiation as much as possible within the chamber. Antennas to be used for heat pumping are preferably of high directivity where the antenna beam is pointed to a cold region such as the zenith of the sky. The system for electromagnetic heating is similar to that for electromagnetic cooling except heat flow is reversed. Here, the antennas outside a chamber have a highly focused beam to a hot area, such as the sun. The collected heat is channeled into an area to be heated by low-directivity antennas within an enclosed volume to be heated.

Electromagnetic cooling and heating

A electrical switch has a first substrate, a first conducting layer disposed on the first substrate, a first dielectric layer disposed on the first conducting layer and a second conducting layer disposed on the first dielectric layer, and the second conducting layer disposed on the second substrate, and a conductive via connected to the first conducting layer and extending through the first dielectric layer. Active dielectric has a first conductor, a first dielectric layer disposed on the first conducting layer, one or more electrical switches disposed on the first dielectric layer, a dielectric layer disposed between neighboring electrical switches, the second dielectric layer disposed on the last electrical switch, and the second conducting layer disposed on the second dielectric layer.

Electronic switch and active artificial dielectric

A capacitor includes a first plate and a second plate parallel to the first plate. An RF source includes a first line and a second line through which RF is fed. The first line is electrically connected to the first plate. The second line is passed through the first and second plates and then looped around the first and second plates, and the pass and loop of the second line is repeated at least once. The second line is then passed through the first plate and electrically connected to the second plate to form a capacitor having negative capacitance.

Capacitor with negative capacitance

A microstrip antenna includes a dielectric substrate, a radiating plate, and a single feed connection. In these instances, the rectangular radiating plate is affixed to the dielectric substrate and having a center point, and the radiating patch defines a first aperture and a second aperture on opposite sides of the center point, each aperture having a center longitudinally aligned with the center point. The single feed connection is laterally offset from a point on a virtual line, wherein the virtual line is located between two opposite corners of the rectangular radiating patch and passes through the center point.

Circular polarized microstrip antenna using a single feed

A device for collecting energy has a moving conducting body and with capacitive plates at the edge. When an incoming wave is incident upon the energy collection device, currents are induced on the moving conducting body, in turn having charges accumulated at the capacitive plates that are attached to the edge of the moving conducting body. As the accumulated charges move along with the conducting body, time-varying magnetic field is produced nearby, from which power is collected by various energy collection devices such as inductive and capacitive coupling devices. It is also possible to collect the energy by putting touch brushes on the charge-stored capacitive plates directly. Also the accumulated charges and consequently the amount of collected power are enhanced by applying the external magnetic field to the moving conducting body.

Device for energy mining

A device for collecting energy has first, second and third capacitive plates, each spaced from, substantially parallel to, and electromagnetically coupled to each other. An inductor is coupled between two of the plates, and a load resistance is inductively coupled to the inductor for drawing energy from electromagnetic field excitation between the plates. In a further embodiment, the inductor includes a first inductor coupled in series with a second inductor, and the load resistance is inductively coupled to the second inductor for drawing energy from electromagnetic field excitation between the plates, and the device further includes a first capacitor coupled in parallel with and spaced apart from the first inductor, and a second capacitor coupled between the first and second capacitive plates. In a still further embodiment, energy is collected by a coaxial transmission feed line.

Device for collecting energy wirelessly

A device for collecting energy has first, second, and third capacitive plates, each spaced from, substantially parallel to, and electromagnetically coupled to each other. An inductor is coupled between two of the plates, and a load resistance is inductively coupled to the inductor for drawing energy from electromagnetic field excitation between the plates. In a further embodiment, the inductor includes a first inductor coupled in series with a second inductor, and the load resistance is inductively coupled to the second inductor for drawing energy from electromagnetic field excitation between the plates, and the device further includes a first capacitor coupled in parallel with and spaced apart from the first inductor, and a second capacitor coupled between the first and second capacitive plates. In a still further embodiment, energy is collected by a coaxial transmission feed line.

A microstrip antenna has a single dielectric layer with a conductive ground plane disposed on one side, and an array of spaced apart radiating patches disposed on the other side of the dielectric layer. The radiating patches are interconnected with a feed terminal via stripline elements. Responsive to electromagnetic energy, a high-order standing wave is induced in the antenna and a directed beam is transmitted from and/or received into the antenna. A dual-mode embodiment is configured such that standing wave nodes occur at the intersection of orthogonally situated striplines to minimize cross-polarization levels of the signals and the cross-talk between the two modes of operation.

Microstrip array antenna

Disclosed is an apparatus which reduces the number of phase shifters required in an antenna array. This is accomplished by supplying standing waves from the phase shifters to each of the radiating elements in a column or row. The standing waves in the rows are orthogonal to the standing waves in the columns. Each of the radiating elements combines the applied standing waves, the phases of which determine the angle of the resultant beam.

Beam steering array antenna method and apparatus

A wireless communication device includes an antenna configured with two conductive elements separated by an insulating medium. One conductive element is a ground plane and the other is a microstrip line. The ground plane is formed with a bend proximate an end. The microstrip line and the ground plane exhibit a characteristic impedance that may vary along the length of the microstrip line. The separation distance of the microstrip line from the ground plane is changed to reduce the resonant frequency of the microstrip line. A second microstrip line with an open end and another end shorted to the ground plane is operative to prevent RF current from flowing on the backside of the ground plane. A backside of the ground plane and the second microstrip line may be covered with a lossy magnetic medium to reduce the near field above the backside of the ground plane.

Methods and apparatus for implementation of an antenna for a wireless communication device

A wireless communication device includes an antenna configured with two conductive elements separated by an insulating medium providing a separation distance. One conductive element is a ground plane and the other is a microstrip line. The microstrip line and the ground plane exhibit a characteristic impedance that may vary along the length of the microstrip line. The separation distance of the microstrip line from the ground plane is changed to reduce the resonant frequency of the microstrip line. A second microstrip line with an open end and another end shorted to the ground plane is operative to prevent RF current from flowing on the backside of the ground plane. A backside of the ground plane and the second microstrip line may be covered with a lossy magnetic medium to reduce the near field in the space above the backside of the ground plane.

An apparatus and method to reduce the size of a microstrip antenna without sacrificing antenna efficiency too much are described. The antenna structure includes discontinuity of strip width in the middle of the antenna patch to reduce the size of the antenna at a given resonant frequency. The antenna structure further includes a plurality of patches of differing widths connected to each other at junctions. The junctions are placed symmetrically to ensure maximum radiation at the boresight and also to further reduce cross-polarization levels. A coaxial feed is connected at a predetermined location near the center of a patch, having a narrower width, in order to match the input impedance of the antenna to the coaxial feed.

Microstrip antenna employing width discontinuities

A microstrip antenna has first and second cylindrically-shaped dielectric layers having first sides secured together with an array of conducting strips conformally interposed therebetween, the strips being spaced to define a slot between each pair of adjacent strips. A conductive ground plane is disposed on an interior second side of the first dielectric layer, and an array of spaced apart radiating patches are conformally disposed on an exterior second side of the second dielectric layer, each of which patches is positioned over a corresponding slot. Responsive to electromagnetic energy, a high-order standing wave is induced in the antenna and a directed beam is transmitted from and/or received into the antenna.

Cylindrical double-layer microstrip array antenna

The present invention is an antenna comprising a microstrip having upper and lower layers for producing leaky wave radiation. Circularly shaped patches are located on the two layers for circularly polarizing the leaky wave radiation. The present invention provides a microstrip antenna that can produce wideband, circularly polarized radiation. The antenna, therefore, is a compact, low cost, rugged, conformal, planar, and circularly polarized microstrip antenna. The antenna combines the advantages of wideband circularly polarized radiation with the advantages of lightweight, low profile, low cost, and planar microstrip antennas.

Growing community of inventors

Dallas, TX, United States of America

Choon Sae Lee