X-cyte, Inc.

Crystal Technology, Inc.

Other

Siemens Components, Inc.

Crystal Technologies, Inc.

Halvor Skeie

Paul A Nysen

Donald Armstrong

An acoustic wave identification transponder device, having a substrate, an electroacoustic transfer generating an acoustic wave in said substrate and a set of encoding elements disposed in a path of the acoustic wave for modifying the acoustic wave, having elements which reflect portions of the acoustic wave having a component orthogonal to the incident wave. The reflectors may be, for example, trackchangers or reflective arrays compressors (RAC). The wave may be phase-amplitude modulated for increased efficiency expressed in bits per tap. Such phase amplitude modulation is preferably imposed by partial beam width phase delay elements disposed within an acoustic beam path.

Surface acoustic wave modulator

A backscatter transponder interrogator, comprising a transmitter, emitting an interrogation signal for interacting with a backscatter transponder within an interrogation field, a plurality of antennas, each having a different and complementary property, such that a backscatter response from a backscatter transponder is likely to be preferentially received by at least one of said at least two antennas, a receiver, selecting an output from a selected antenna, and demodulating the backscatter response to produce an information signal, and a digitally controlled oscillator, producing an output controlling said transmitter and employed by said receiver to demodulate the backscatter response. The interrogator may have a plurality of transmit antennas. The antennas may have respectively different polarization properties, e.g., horizontal and vertical polarization. The interrogator may implement null steered polarization cancellation to distinguish between backscatter transponders within the interrogation field.

Backscatter transponder interrogation device

An acoustic wave identification transponder device, having a substrate, an electroacoustic transducer generating an acoustic wave in said substrate and a set of encoding elements disposed in a path of the acoustic wave for modifying the acoustic wave, having elements which reflect portions of the acoustic wave having a component orthogonal to the incident wave. The reflectors may be, for example, trackchangers or reflective arrays compressors (RAC). The wave may be phase-amplitude modulated for increased efficiency expressed in bits per tap. Such phase amplitude modulation is preferably imposed by partial beam width phase delay elements disposed within an acoustic beam path.

Surface acoustic wave transponder configuration

A plurality of optic modulators implemented using segmented electrodes and nonparallel waveguide structures are cascaded using optical couplers to provide a linearization of the overall electro-optic transfer function. Each of the optical modulators which are coupled in cascade have an electrode structure which is divided into a plurality of relatively small segments. The segments are connected via bond wires and transmission lines on an adjoining microwave circuit board. Each of the optical modulators includes a pair of waveguides which are sloped so as to result in a nonparallel waveguide structure which reduces acoustic effects, e.g., ripple. By using a plurality of small segments to implement the electrode structure a high degree of sensitivity is achieved as compared to when a single lengthy electrode structure is used. The combination of the non-parallel waveguides and a segmented electrode provides for a relatively large flat frequency response, e.g., in excess of 1 GHz. The electrode structure is also designed to minimize the effective capacitance of the electrode structure to thereby broaden the bandwidth of the optic modulator of the present invention as compared to devices using solid center electrodes.

Linearized optic modulator with segmented electrodes

An optic modulator implemented on a substrate that is conductive to light and which includes a pair of light waveguides formed on the substrate is described. The waveguides extend substantially coextensively with one another and are separated from one another by a transverse distance that gradually varies along the courses of the waveguides. The waveguides are arranged to pass between an outer electrode assembly and a center electrode assembly. The outer electrode assembly substantially surrounds the center electrode assembly in such a manner as to create an electric field between the center electrode assembly and the outer electrode assembly when a voltage is applied across the outer and center electrode assemblies. In order to minimize the effective capacitance resulting from the interaction of the outer electrode assembly and the center electrode assembly, the center electrode assembly is implemented using a plurality of individual electrode segments arranged to maximize the electric field strength generated in the area though which the waveguides pass while minimizing the overall effective capacitance. By using such a center electrode configuration, the capacitance is decreased and thus the overall bandwidth of the modulator of the present invention is increased as compared to modulators using a single solid center electrode.

Integrated optic modulator with reduced capacitance electrode

An optical modulator having an electrode structure which is divided into a plurality of relatively small segments is described. The segments are connected via bond wires and transmission lines on an adjoining microwave circuit board. The optical modulator includes a pair of waveguides which are sloped so as to result in a nonparallel waveguide structure which reduces acoustic effects, e.g., ripple. By using a plurality of small segments to implement the electrode structure a high degree of sensitivity is achieved as compared to when a single lengthy electrode structure is used. The combination of the non-parallel waveguides and a segmented electrode provides for a relatively large flat frequency response, e.g., in excess of 1 GHz. The electrode structure is also designed to minimize the effective capacitance of the electrode structure to thereby broaden the bandwidth of the optic modulator of the present invention as compared to devices using solid electrodes.

Integrated optic modulator with segmented electrodes and sloped

An integrated cascaded optical phase modulator for providing linearized complementary modulated light output signals consists of the successive cascade of a first phase modulator stage, first fixed optical coupler, second phase modulator stage, and second fixed optical coupler Rf modulating signals applied to each phase modulator stage are adjusted in amplitude, for compensating for errors in the coupling angles of the first and second optical couplers. The levels of DC bias voltages applied to each phase modulator stage are adjusted for compensating for asymmetric phase modulation.

Apparatus and method for cascade coupled integrated optical phase

A Y-branch type first interferometric modulator, and a coupler structure type second interferometric modulator are connected in cascade. The levels of DC bias voltages applied to the first and second interferometric modulators, respectively, are adjusted for maximizing the linearity of a modulated output light signal. The configuration of input and output coupler structures of the second interferometric modulator are predetermined for also contributing to maximizing the linearity of the output signal.

Apparatus and method for linearized cascade coupled integrated optical

A 'passive interrogator label system' (PILS) is disclosed with passive, SAW transponders which are capable of receiving an interrogation signal, processing this signal and transmitting a reply signal that is derived from the interrogation signal and contains encoded information. The SAW transducers employed in the transponders are operated at their third harmonic and comprise split fingers which reduce SAW reflections. These transducers are also shaped to increase their bandwidth and to reduce their capacitance. The bus bars connecting the transducers are formed of double thickness to reduce ohmic resistance losses and these bus bars as well as the transponder phase delay pads have two levels of serrations on their edges to substantially cancel reflections. SAW reflectors in the transponder are provided with shorts between successive fingers to reduce ohmic resistance losses and to render them less susceptible to fabrication errors.

Passive interrogator label system with a surface acoustic wave

A 'passive interrogator label system' (PILS) comprises an interrogator for transmitting an interrogation signal, one or more 'labels' or passive transponders which produce a reply signal containing coded information in response to the interrogation signal, and a receiver and decoder for receiving the reply signal and decoding the information contained in it. The frequency of the interrogation signal assumes a plurality of frequency values within a prescribed frequency range. The decoder includes a mixer (4 quadrant multiplexer) for mixing together the interrogation and reply signals (or signals derived therefrom) to produce a further signal containing frequencies which are the sum and difference of the interrogation and reply signals. A signal processor, responsive to this further signal produced by the mixer, detects at least some of the frequencies contained in this further signal and determines the informational code associted with the transponder.

System for interrogating a passive transponder carrying phase-encoded

A SAW device using a first reflector (13) and a second reflector (14) is arranged to provide compensation for temperature effects. The temperature effects are due to the anisotropic characteristics of piezoelectric material commonly used as the substrate and wave medium for the acoustic waves in the SAW devices. These materials typically exhibit a temperature dependent, preferential direction of transmission which if not compensated results in a temperature dependent signal attenuation. An additional technique using a non-reflective portion 22 offsets non-uniformity which occurs in the amplitude distribution of the reflected acoustic wave. Each reflector (13 and 14) may include its respective non-reflective portion (A.sub.1 and A.sub.2).

Compensation techniques for temperature effects and non-uniform

A passive transponder for use in an interrogation/transponder system comprises a substrate having a substrate surface defining a path of travel for surface acoustic waves; at least one transducer element arranged on the surface for converting between electrical energy and surface acoustic wave energy which propagates along the path of travel; and a circuit, connected to the transducer element(s), for supplying interrogating signals to the transducer element(s) and for receiving reply signals therefrom. In order to minimize insertion losses in the substrate, acoustic wave reflectors are provided to reflect the surface acoustic waves back towards the transducer element(s).

Surface acoustic wave passive transponder having acoustic wave reflectors

A passive transponder for use in an interrogation/transponder system comprises a substrate having a substrate surface defining a path of travel for surface acoustic waves; a launch transducer element arranged on the surface for converting interrogating signals into surface acoustic waves which propagate along the path of travel; a plurality of tap transducer elements arranged on the surface at spaced intervals along the path of travel for converting surface acoustic waves into respective output signals; and a circuit, connected to the tap transducer elements, for combining the output signals of these transducer elements to form reply signals. In order to control the delay time from transducer element to transducer element, one or more 'delay pads' are provided on the substrate surface between these transducer elements.

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San Jose, CA, United States of America

Halvor Skeie