Abstract: An octave bandwidth conformal cavity-backed slot antenna includes a ground plane with a number of different length slits that come together at the central feedpoint. The slit length varies from one-half a wavelength at the highest frequency at which the antenna is to operate for the short side to one wavelength at the highest frequency for the long side, with the proximal ends of the slits having a common feedpoint. Such slot antennas may be arrayed in a quad configuration. Because the trapezoidal envelope of the antenna induces the phase-center to shift with frequency, when two are arrayed with short sides adjacent, the spacing between them results in a phase center from one antenna to the next that is effectively within half a wavelength at all frequencies.

Abstract: A Radio Frequency Identification (RFID) device antenna has a feed region of interdigitated fingers. The interdigitated fingers have parallel centerlines and are spaced one from another. A chip having opposing ends overlays opposing interdigitated fingers. A coupling is established between the chip and the antenna at the interdigitated fingers.

Abstract: An octave bandwidth conformal cavity-backed slot antenna includes a ground plane with a number of different length slits that come together at the central feedpoint. The slit length varies from one-half a wavelength at the highest frequency at which the antenna is to operate for the short side to one wavelength at the highest frequency for the long side, with the proximal ends of the slits having a common feedpoint. Such slot antennas may be arrayed in a quad configuration. Because the trapezoidal envelope of the antenna induces the phase-center to shift with frequency, when two are arrayed with short sides adjacent, the spacing between them results in a phase center from one antenna to the next that is effectively within half a wavelength at all frequencies.

Abstract: Antennas (50) for RFID tags are made to exhibit circular polarization to give the tag an omnidirectional characteristic. The antennas are crossed dipoles (52,54) with respective feed points (56,58). The signal source (60) is coupled to a splitter (62) having output leads (64) directly coupled to the feed point (56) of dipole (52). The other output leads (66) from splitter (62) are coupled to a delay line (68) with the delayed output coupled to a feed point (58) of dipole (54).

Abstract: A method for mounting multiple small RFID chips onto larger antenna. The chips are mechanically aligned with an interdigitated gap at the feed point of the antenna by electrostatic or magnetic techniques. In an alternate embodiment RF field coupling between the chips and the antenna is employed.

Abstract: A method for mounting multiple small RFID chips onto larger antenna. The chips are mechanically aligned with an interdigitated gap at the feed point of the antenna by electrostatic or magnetic techniques. In an alternate embodiment RF field coupling between the chips and the antenna is employed.

Abstract: An antenna comprising a crossed pair of center-fed end-loaded bent-dipole radiators which are structurally embedded into a properly loaded cavity. Broadband, dual independent polarized, and hemisphere field-of-view coverage with low RCS characteristics is provided with this antenna.

Abstract: Antennas (50) for RFID tags are made to exhibit circular polarization to give the tag an omnidirectional characteristic. The antennas are crossed dipoles (52,54) with respective feed points (56,58). The signal source (60) is coupled to a splitter (62) having output leads (64) directly coupled to the feed point (56) of dipole (52). The other output leads (66) from splitter (62) are coupled to a delay line (68) with the delayed output coupled to a feed point (58) of dipole (54).

Abstract: An antenna formed with a number of notch antennas forming an sectional inner ring and a sectional outer ring. Each of the notch antennas having a pair of leaves with a throat end proximate the inner ring and a leaf tip end proximate the outer ring, wherein the leaves are separated by a notch area. There is a lagoon interiorly disposed about the inner ring. At least one feed is coupled to at least one throat end. A lower horizontal loop couples each leaf tip and forms the outer ring. In addition, a plurality of slots separates each of the notch antennas.

Abstract: An antenna comprising a crossed pair of center-fed end-loaded bent-dipole radiators which are structurally embedded into a properly loaded cavity. Broadband, dual independent polarized, and hemisphere field-of-view coverage with low RCS characteristics is provided with this antenna.

Abstract: A cavity-backed wideband slimline flat panel antenna array for providing a steerable beam includes an array of slot antennas, each of which fed by its own individual dipole radiator, with the wide bandwidth being due to the matching impedances of the slot antenna and dipole radiator across the entire frequency band. In one embodiment, an upstanding printed circuit balun feed is connected to each dipole. The dipole elements are located to either side of a slot, and are arrayed on the underneath side of a dielectric layer under the substrate into which the slots are formed, with the dipole elements directly fed by individual upstanding printed circuit baluns which are arrayed beneath the individual slots antennas. The use of the dipole elements, in addition to providing a wider operational bandwidth, also permits feeding each of the slots without having to use striplines which would have to cross each other and therefore not work.

Abstract: A cavity-backed wideband slimline flat panel antenna array for providing a steerable beam includes an array of slot antennas, each of which fed by its own individual dipole radiator, with the wide bandwidth being due to the matching impedances of the slot antenna and dipole radiator across the entire frequency band. In one embodiment an upstanding printed circuit balun feed is connected to each dipole. The dipole elements are located to either side of a slot and are arrayed on the underneath side of a dielectric layer under the substrate into which the slots are formed, with the dipole elements directly fed by individual upstanding printed circuit baluns which are arrayed beneath the individual slots antennas. The use of the dipole elements, in addition to providing a wider operational bandwidth, also permits feeding each of the slots without having to use striplines which would have to cross each other and therefore not work.

Abstract: The present invention features a stacked, multi-band, antenna system consisting of a low-frequency, forward portion and a gridded, rear portion designed for operation at a higher frequency. Both front and rear radiating elements may share a common ground plane or the rear element may form a ground plane for the front element. Typically, the front antenna is a relatively narrow-band, gridded, bow-tie dipole or a similar radiating structure and the rear antenna is a wide-band dipole or slot element. Additional frequency bands may be designed into the inventive system by adding additional dipole or similar antenna elements above, below, or between the front and rear antennas. By properly choosing element sizes and spacings, and orienting the various antennas, a frequency band ratio of as little as 4:1 may be obtained.

Abstract: The present invention provides a compact slotline balun implemented on a 10-mil thick printed circuit card. The balun utilizes a transition region configuration of a six-port network to achieve a good impedance match and low insertion loss across a wide operating band. The balun is typically manufactured using standard printed circuit techniques which yield a thin, flexible, dimensionally stable device.

Abstract: The present invention features a reconfigurable resonant cavity specifically for use with a slot radiator. A series of internal planes with frequency-selective materials disposed on their top surfaces, in conjunction with switchable shorting pins, is used to reconfigure the cavity's resonant frequency. PIN diodes, MEMS or other photonically or electrical activated switching devices may be used to selectively “activate” shorting pins. A single resonant cavity may be electrically reconfigured to operate at two, three, or even more different frequency bands.

Abstract: The present invention provides a compact slotline balun implemented on a 10-mil thick printed circuit card. The balun utilizes a transition region configuration of a six-port network to achieve a good impedance match and low insertion loss across a wide operating band. The balun is typically manufactured using standard printed circuit techniques which yield a thin, flexible, dimensionally stable device.

Abstract: The present invention features a reconfigurable resonant cavity specifically for use with a slot radiator. A series of internal planes with frequency-selective materials disposed on their top surfaces, in conjunction with switchable shorting pins, is used to reconfigure the cavity's resonant frequency. PIN diodes, MEMS or other photonically or electrical activated switching devices may be used to selectively “activate” shorting pins. A single resonant cavity may be electrically reconfigured to operate at two, three, or even more different frequency bands.