Abstract: Described is an in-band full-duplex (IBFD) antenna having direction finding capability. The IBFD antenna includes a transmit antenna having an omnidirectional radiation pattern and a receive antenna configured to provide a plurality of difference beams. The IBFD antenna may be disposed on a moving platform to cover all angles around the moving platform.

Abstract: Described is a stacked patch antenna array scan-capable to 55 degrees and operable over an octave or greater frequency bandwidth.

Abstract: A compact shallow cavity-backed discone antenna array for conformal omnidirectional antenna applications is disclosed. The antenna array comprises a plurality of discone antennas arranged in a ring array within a circular contoured conical cavity. The cavity is covered with an electrically transparent radome. The individual discone antenna elements are fed with coaxial transmission lines. Good performance is demonstrated by simulation and by experiment in terms of reflection coefficient and omnidirectional gain radiation patterns from about 960 MHz to 1220 MHz. In one embodiment, the shallow cavity-backed discone antenna array may be used as a flush-mounted antenna that conforms to the outer mold line of an aircraft.

Abstract: A compact shallow cavity-backed discone antenna array for conformal omnidirectional antenna applications is disclosed. The antenna array comprises a plurality of discone antennas arranged in a ring array within a circular contoured conical cavity. The cavity is covered with an electrically transparent radome. The individual discone antenna elements are fed with coaxial transmission lines. Good performance is demonstrated by simulation and by experiment in terms of reflection coefficient and omnidirectional gain radiation patterns from about 960 MHz to 1220 MHz. In one embodiment, the shallow cavity-backed discone antenna array may be used as a flush-mounted antenna that conforms to the outer mold line of an aircraft.

Abstract: Described is a stacked patch antenna array scan-capable to 55 degrees and operable over an octave or greater frequency bandwidth.

Abstract: Described is a printed circuit antenna array including at least one castellated substrate. Also described is a stacked patch antenna array having at least one castellated substrate.

Abstract: Described is a printed circuit antenna array including at least one castellated substrate. Also described is a stacked patch antenna array having at least one castellated substrate.

Abstract: A surface acoustic wave (SAW) device comprising a piezoelectric substrate having a working surface with an active zone capable of propagating an acoustic wave on said working surface; at least one interdigital transducer on the working surface, having interdigital fingers aligned in the active zone for inducing or receiving surface acoustic waves in the active zone; and a heating element on the working surface; wherein the transducer, heating element and preferably a temperature sensor are monolithically formed on the substrate.

Abstract: A surface acoustic wave (SAW) device comprising at least one heating element formed on the substrate; at least one temperature sensor having a first electric component on the substrate whose resistance varies with the temperature of the substrate and a second electric component whose resistance does not vary; and a temperature controller including an operational amplifier bonded in thermally conductive relationship to the substrate. The operational amplifier is responsive to the output of the temperature sensor to apply power to the heating element and thereby maintain the temperature of the substrate within a predetermined temperature range. The transducer, heating element, and first component are monolithically formed on the substrate, and only three electrical connections are on the substrate at voltage to off-SAW die points.

Abstract: A surface acoustic wave (SAW) device comprising at least one heating element formed on the substrate; at least one temperature sensor having a first electric component on the substrate whose resistance varies with the temperature of the substrate and a second electric component whose resistance does not vary; and a temperature controller including an operational amplifier bonded in thermally conductive relationship to the substrate. The operational amplifier is responsive to the output of the temperature sensor to apply power to the heating element and thereby maintain the temperature of the substrate within a predetermined temperature range. The transducer, heating element, and first component are monolithically formed on the substrate, and only three electrical connections are on the substrate at voltage to off-SAW die points.

Abstract: A wideband biconical antenna arrangement is disclosed having a feed arrangement that services a second antenna positioned above the biconical antenna. The feed for the second antenna is configured as a helix that spirals around an outer periphery of the upper and lower cones of the biconical antenna along the biconical antenna's cylindrical radiating aperture. In one embodiment, the feed is a coaxial cable disposed within a hollow metal tube. This helix feed does not substantially degrade the performance of the wideband biconical antenna. The wideband biconical antenna has its feed disposed within a central conduit of the biconical antenna. The biconical antenna has at least one octave of bandwidth, and in one embodiment the second antenna also has at least one octave of bandwidth.

Abstract: A surface acoustic wave (SAW) device comprising a piezoelectric substrate having a working surface with an active zone capable of propagating an acoustic wave on said working surface; at least one interdigital transducer on the working surface, having interdigital fingers aligned in the active zone for inducing or receiving surface acoustic waves in the active zone; and a heating element on the working surface; wherein the transducer, heating element and preferably a temperature sensor are monolithically formed on the substrate.

Abstract: A surface acoustic wave filter includes first and second channels, each channel including at least one input transducer and one input transducer. The transfer functions of the first channel and of the second channel are in phase in the passband of the filter and in antiphase in the rejection band of the filter. The filter enables the use of frequency responses for each channel, with wide bands enabling high reduction of the size of the filter while at the same time reducing the rejection band of the total filter. Such a filter may find particular application to mobile telephony.

Abstract: The transducer according to the invention, driven in differential mode, consists of at least a first transducer (5) and a second transducer (6) which are connected in parallel so as to obtain the symmetry of the differential inputs, respectively forming a first and a second acoustic channel; the two transducers (5, 6) exhibiting a specified longitudinal offset with respect to one another. Applications: mobile radio filters.

Abstract: The disclosure relates to differential input/output surface acoustic wave devices with proximity coupling. The disclosed device comprises a whole number N of acoustic channels, where N is at least equal to two. The acoustic channels are coupled together by proximity. A first acoustic channel comprises at least one transducer separated into several parts electrically connected in parallel with one another to form a first differential port (E+) and a second differential port (E-). The polarities of the different parts of the transducer are chosen so that the first differential port (E+) and the second differential port (E-) are electrically symmetrical. Application in particular to surface acoustic wave filters for portable telephones.

Abstract: The invention concerns unidirectional ground-wave transducers using an alternating series of emitter cells (E) and reflector cells (R).The invention consists in using, in the emitter cells (E), fingers having a width of .lambda./3 spaced apart by a distance of 2 .lambda./3; and, in the reflector cells (R), fingers having a width of .lambda./4 spaced apart by a distance of .lambda./2.Using identical engraving precision, the invention makes it possible to increase by 50% the frequency at which the unidirectional transducer thus produced can be used.

Abstract: Ultrahigh-frequency surface acoustic wave filter has a two-channel structure with, preferably, a symmetric pair of input transducers (2, 6) and an associated pair of weighted output transducers (8, 9), and an associated pair of reflectors (14, 15). These reflectors (14, 15) are offset by a distance (d) equal to a quarter of the acoustic-wave wavelength (.lambda.), within an integral number of half wavelengths. The weightings of the output transducers are chosen in order to provide the desired impulse response.

Abstract: A low loss microwave surface acoustic wave filter, comprising input (2, 3) and output (4, 5) transducers, acoustically associated with coupling transducers (6, 7).The relative positions of the transducers 2 to 7) and of their O reflectors are chosen, having regard to the weightings of the coupling transducers (6, 7) in order to obtain the desired transfer function for this filter.

Abstract: In a transducer for surface waves, an alternating succession of transmitter cells and reflector cells is used. The transmitter cells transmit surface waves in phase opposition, leftwards and rightwards. The reflector cells have a reflection coefficient that is in phase opposition between the left-hand side and the right-hand side. The waves transmitted by the transmitter cells interfere with the waves reflected by the reflector cells, destructively in one direction and constructively in the other direction. This enables the making of transducers with spacings equal to .lambda./4 and .lambda./6 only.

Abstract: To reduce the frequency bandwidth of an interdigital transducer, acting as an image-impedance connected interdigital transducer in a surface acoustic wave filter with low insertion losses, at least the center-to-center spacing between a first electrode or finger of a first comb, central to the transducer, and a second finger of a second adjacent comb is equal to R.lambda..sub.0 /2, where .lambda..sub.0 is the central wavelength and R is a whole number strictly greater than 1. The center-to-center spacings between the other first and second fingers are at least equal to R.lambda..sub.0 /2. An increase in the optimal length of an image-impedance connected interdigital transistor is obtained by reducing the number of active fingers per unit of length. The greater the reduction factor chosen, the narrower will be the frequency band of the transducer.