Abstract: A directional repeater system is presented with a simple architecture composed of wideband receive and transmit antennas, a high gain low-power amplifier and a bandpass filter suitable for use in the 2450 MHz ISM band. Close to 70 dB of isolation between transmit and receive antennas over the entire band is achieved for a compact structure. The isolation between the transmit and receive antennas is achieved using polarization mismatch between orthogonal double-stack patch antennas and a two-element receive antenna whose elements are appropriately located with respect to the edge of the substrate ground plane and the transmit antenna to cancel the signal leakage from the transmit antenna to the individual receive antennas. A major advantage of this invention is that the entire bandwidth can be used going through a chain of repeaters whereas for conventional repeaters the available bandwidth is halved for every repeater in the chain.

Abstract: A broadband fully micromachined transition from rectangular waveguide to cavity-backed coplanar waveguide line for submillimeter-wave and terahertz application is presented. The cavity-backed coplanar waveguide line is a planar transmission line that is designed and optimized for minimum loss while providing 50 Ohm characteristic impedance. This line is shown to provide less than 0.12 dB/mm loss over the entire J-band. The transition from cavity-backed coplanar waveguide to a reduced-height waveguide is realized in three steps to achieve a broadband response with a topology amenable to silicon micromachining. A novel waveguide probe measurement setup is also introduced and utilized to evaluate the performance of the transitions.

Abstract: A borehole drilling communication system that includes a hydraulic drill, a communication module, and a transducer. The hydraulic drill has a drill pipe and a drill head where the communication module is located, The transducer has an input end and is mounted on the drill pipe adjacent the communication module. The communication module includes a first output terminal electrically connected to the drill pipe and a second output terminal electrically connected to the input end of the transducer. The transducer includes a helical conductor that is positioned coaxially over a section of the drill pipe at the drill head, with the helical conductor terminating at an electrically isolated free end. During use in borehole drilling, data sent from the communication module is launched by the transducer and transmitted along the drill pipe as a single conductor transmission line.

Abstract: A directional repeater system is presented with a simple architecture composed of wideband receive and transmit antennas, a high gain low-power amplifier and a bandpass filter suitable for use in the 2450 MHz ISM band. Close to 70 dB of isolation between transmit and receive antennas over the entire band is achieved for a compact structure. The isolation between the transmit and receive antennas is achieved using polarization mismatch between orthogonal double-stack patch antennas and a two-element receive antenna whose elements are appropriately located with respect to the edge of the substrate ground plane and the transmit antenna to cancel the signal leakage from the transmit antenna to the individual receive antennas. A major advantage of this invention is that the entire bandwidth can be used going through a chain of repeaters whereas for conventional repeaters the available bandwidth is halved for every repeater in the chain.

Abstract: A device comprising a thin film solar cell with an integrated flexible antenna, such as a meander line antenna, is disclosed. In an embodiment, the device comprises a substrate and an array of solar cells disposed on the substrate, wherein the array of solar cells are interconnected by metal conductors that carry DC power from the solar cells and which form at least part of the flexible antenna. In their capacity as an antenna, the metal conductors operate cooperatively with the solar cells to radiate an RF signal, receive an RF signal, or both radiate and receive an RF signal. The device optionally comprises a choke disposed on the substrate and electrically coupled to the array of solar cells, wherein the choke operates to impede conduction of the RF signal. A method of making the disclosed device is also disclosed.

Abstract: A fracture interrogation system includes an antenna adapted for placement in a subterranean wellbore and a plurality of pseudoparticles adapted for distribution with a proppant material into hydraulic fractures along the wellbore. The presence of the pseudoparticles in the hydraulic fractures is detectable by the antenna. The pseudoparticles can include a magnetoelastic resonator having a resonant frequency. An interrogation field excites the resonators at the resonant frequency for detection by the antenna. The same or a different antenna can act as the interrogation field source, and the system can be configured to operate in a talk-and-listen mode to better separate the response signal from the interrogation signal. Electromagnetic, mechanical, or acoustic impulses can be used to excite resonators of the pseudoparticles.

Abstract: A broadband fully micromachined transition from rectangular waveguide to cavity-backed coplanar waveguide line for submillimeter-wave and terahertz application is presented. The cavity-backed coplanar waveguide line is a planar transmission line that is designed and optimized for minimum loss while providing 50 Ohm characteristic impedance. This line is shown to provide less than 0.12 dB/mm loss over the entire J-band. The transition from cavity-backed coplanar waveguide to a reduced-height waveguide is realized in three steps to achieve a broadband response with a topology amenable to silicon micromachining. A novel waveguide probe measurement setup is also introduced and utilized to evaluate the performance of the transitions.

Abstract: A frequency scanning traveling wave antenna array is presented for Y-band application. This antenna is a fast wave leaky structure based on rectangular waveguides in which slots cut on the broad wall of the waveguide serve as radiating elements. A series of aperture-coupled patch arrays are fed by these slots. This antenna offers 2° and 30° beam widths in azimuth and elevation direction, respectively, and is capable of ±25° beam scanning with frequency around the broadside direction. The waveguide can be fed through a membrane-supported cavity-backed CPW which is the output of a frequency multiplier providing 230˜245 GHz FMCW signal. This structure can be planar and compatible with micromachining application and can be fabricated using DRIE of silicon.

Abstract: A matching technique and the field enhancement at the terminals of a bowtie nanoantenna is presented to develop compact, highly efficient, and flexible thermophotovoltaic (TPV) cells. The bowtie antenna is designed for maximum power transfer to a near infrared band of a TPV cell. In one example, a small cube of indium gallium arsenside antimode or another suitable material with a low bandgap energy of 0.52 eV is mounted at the terminals of the antenna. Such a load presents a frequency dependent impedance with a high resistance and capacitance at the desired frequency (180 THz). For maximum power transfer, a high impedance bowtie antenna operating at the anti-resonance mode connected to an inductive transmission line to compensate for the load capacitance is realized. The same antenna and load configuration with the semiconductor material used in photoconductive mode is used to realize a sensitive uncooled photodetector.

Abstract: A frequency scanning traveling wave antenna array is presented for Y-band application. This antenna is a fast wave leaky structure based on rectangular waveguides in which slots cut on the broad wall of the waveguide serve as radiating elements. A series of aperture-coupled patch arrays are fed by these slots. This antenna offers 2° and 30° beam widths in azimuth and elevation direction, respectively, and is capable of ±25° beam scanning with frequency around the broadside direction. The waveguide can be fed through a membrane-supported cavity-backed CPW which is the output of a frequency multiplier providing 230˜245 GHz FMCW signal. This structure can be planar and compatible with micromachining application and can be fabricated using DRIE of silicon.

Abstract: A radio repeater system is provided that utilizes miniaturized antennas and a meta-material channel isolator. The radio repeater is comprised of: a receive antenna configured to receive a signal at a desired channel frequency; a transmit antenna configured to transmit the signal at the channel frequency; an amplifier electrically connected between the receive antenna and the transmit antenna; and an array of resonating circuits disposed spatially between the receive antenna and the transmit antenna. Each resonating circuit is designed to resonant at the channel frequency and thereby suppress propagation of surface waves between the antennas.

Abstract: Frequency-selective surface (FSS) structures that may be used in a variety of different filtering capacities and applications. According to exemplary embodiments, there is disclosed: 1) a one-sided FSS structure that has a conductive grid and conductive loops located on the same side of a thin substrate and exhibits a single pole frequency response; 2) a multiple layer FSS structure that has several one-sided FSS layers and exhibits a multiple pole frequency response; 3) a loop/loop tunable FSS structure where the frequency response can be adjusted or tuned with a bias network; 4) a grid/grid tunable FSS structure where the frequency response can be adjusted or tuned without the use of bias network; and 5) an antenna arrangement that has a FSS structure placed over top of antenna array so that the need for separate components, like bulky filters in a transceiver chain, can be eliminated.

Abstract: A radio repeater system is provided that utilizes miniaturized antennas and a meta-material channel isolator. The radio repeater is comprised of: a receive antenna configured to receive a signal at a desired channel frequency; a transmit antenna configured to transmit the signal at the channel frequency; an amplifier electrically connected between the receive antenna and the transmit antenna; and an array of resonating circuits disposed spatially between the receive antenna and the transmit antenna. Each resonating circuit is designed to resonant at the channel frequency and thereby suppress propagation of surface waves between the antennas.

Abstract: Frequency-selective surface (FSS) structures that may be used in a variety of different filtering capacities and applications. According to exemplary embodiments, there is disclosed: 1) a one-sided FSS structure that has a conductive grid and conductive loops located on the same side of a thin substrate and exhibits a single pole frequency response; 2) a multiple layer FSS structure that has several one-sided FSS layers and exhibits a multiple pole frequency response; 3) a loop/loop tunable FSS structure where the frequency response can be adjusted or tuned with a bias network; 4) a grid/grid tunable FSS structure where the frequency response can be adjusted or tuned without the use of bias network; and 5) an antenna arrangement that has a FSS structure placed over top of antenna array so that the need for separate components, like bulky filters in a transceiver chain, can be eliminated.

Abstract: A radar system is disclosed, which comprises an orthogonal frequency division multiplexing (OFDM) modem and a frequency scanning antenna. In transmit, the OFDM modem modulates radar waveforms and the frequency scanning antenna radiates the OFDM modulated radio frequency (RF) energy. In receive mode, the frequency scanning antenna captures the echoes and the OFDM modem demodulates the echoes. Directionality of the frequency scanning antenna is dependent upon RF carrier frequency. In other features, the radar system further comprises a transmit/receive (T/R) module that up-converts and amplifies the OFDM modulation, and outputs the amplified signal to the frequency scanning antenna. The T/R module amplifies and down-converts a received RF echo from the frequency scanning antenna and outputs the down-converted echo to the OFDM modem. A plurality of scanning angles are measured simultaneously.

Abstract: An antenna assembly that has particular application for a hand held reader that interrogates sensors embedded within a vehicle tire, such as RFID sensors and tire pressure sensors. In one embodiment, the antenna assembly includes a first antenna operating in the 432-435 MHz range that employs a meander-line slot that provides increased antenna cross-polarization so that the sensor can be interrogated regardless of the antenna orientation and polarization. The antenna assembly also includes two RFID antennas that operate in the 902-928 MHz range that are planar antenna that make the antenna bi-directional, polarization free and a wide enough bandwidth for the RFID interrogation.

Abstract: A radar system is disclosed, which comprises an orthogonal frequency division multiplexing (OFDM) modem and a frequency scanning antenna. In transmit, the OFDM modem modulates radar waveforms and the frequency scanning antenna radiates the OFDM modulated radio frequency (RF) energy. In receive mode, the frequency scanning antenna captures the echoes and the OFDM modem demodulates the echoes. Directionality of the frequency scanning antenna is dependent upon RF carrier frequency. In other features, the radar system further comprises a transmit/receive (T/R) module that up-converts and amplifies the OFDM modulation, and outputs the amplified signal to the frequency scanning antenna. The T/R module amplifies and down-converts a received RF echo from the frequency scanning antenna and outputs the down-converted echo to the OFDM modem. A plurality of scanning angles are measured simultaneously.

Abstract: An antenna assembly that has particular application for a hand held reader that interrogates sensors embedded within a vehicle tire, such as RFID sensors and tire pressure sensors. In one embodiment, the antenna assembly includes a first antenna operating in the 432-435 MHz range that employs a meander-line slot that provides increased antenna cross-polarization so that the sensor can be interrogated regardless of the antenna orientation and polarization. The antenna assembly also includes two RFID antennas that operate in the 902-928 MHz range that are planar antenna that make the antenna bi-directional, polarization free and a wide enough bandwidth for the RFID interrogation.

Abstract: A speed measuring device that employs a Fresnel zone plate lens antenna. The Fresnel lens antenna is mounted to one end of a low profile collection housing, typically cylindrical in configuration. An opposite end of the collection housing includes a back plate having an opening. A transceiver unit is mounted to the outside surface of the back plate so that a transmitter and a detector within the transceiver are in communication with the opening. A signal is transmitted from the transceiver unit through the opening, and is directed by the lens antenna. A reflected signal is received and focused by the lens antenna, and collected by the housing to be directed through the opening to the transceiver.

Abstract: A two-sided overlapping coupled sectorial loop antenna (CSLA). The CSLA includes a ground plane and a dielectric substrate mounted substantially perpendicular thereto. A first metalized trace is deposited on one side of the substrate and a second metalized trace is deposited on the other side of the substrate, where the metalized traces overlap at a center area and are coupled to a common feed at the center area. In one embodiment, the size of the CSLA is further reduced by adding inductors to the traces.