Abstract: An antenna method and apparatus includes a slot antenna configured within a ground plane and a conductive reflector backing the slot antenna and configured to reflect RF energy. The slot antenna, ground plane, and the reflector cooperatively form a reflector-backed slot antenna and a radial-mode waveguide providing an inverse, mirrored, substantially cosecant-squared radiation pattern.

Abstract: A distributed comb tapped multiband antenna structure includes a PIFA-like antenna radiator having tap structures, and a counterpoise to the antenna radiator, wherein the tap structures include shunt connections to the counterpoise. A second antenna radiator is collinear and opposing the antenna radiator while sharing the counterpoise in common with the antenna radiator, such that the antenna structure is configured as a balanced dipole. The antenna structure can be contained internally within a single device housing and can operate over multiple frequency bands. The antenna provides high performance over a considerable bandwidth within each of the multiple frequency bands of operation, even where the frequency bands are not harmonically related.

Abstract: A mobile wireless communication device includes a circulators coupled between a respective communications arrangement and their antennas. Each circulator includes a coupled tuning network, wherein the tuning networks are operable to tune their circulators for maximum isolation from cross coupling between the power amplifiers within an operating frequency band of the respective communications arrangement.

Abstract: An antenna apparatus and method includes an orthogonal slot antenna which overcomes the limitations associated with RF choke between the adjacent slots through various feed techniques. A cavity backed cross-slot antenna includes a horizontal slot antenna, a vertical slot antenna sharing a center portion with the horizontal slot antenna, a first feed for the horizontal slot antenna, and a second feed for the vertical slot antenna, the first feed and the second feed provided to the shared center portion. Another cavity backed cross-slot antenna includes a horizontal slot antenna, a vertical slot antenna, the horizontal slot antenna and the vertical slot antenna share a center portion therebetween, a first feed feeding both halves of the horizontal slot antenna, and a second feed feeding both halves of the vertical slot antenna.

Abstract: An antenna method and apparatus includes a slot antenna configured within a ground plane and a conductive reflector backing the slot antenna and configured to reflect RF energy. The slot antenna, ground plane, and the reflector cooperatively form a reflector-backed slot antenna and a radial-mode waveguide providing an inverse, mirrored, substantially cosecant-squared radiation pattern.

Abstract: The present invention is directed to systems that use frequency selective surfaces (FSS) to aid in the operation of radio frequency identification (RFID) devices and products. In one embodiment, a system for interrogating radio frequency identification (RFID) tags includes a conveyor belt and an RFID reader. The conveyor belt has a first surface and a second surface. The first surface is configured to receive an item to which an RFID tag is affixed and the second surface is configured to slide on a metal slide plate. The RFID reader is configured to transmit instructions embodied in a radio frequency (RF) signal to the RFID tag, wherein the metal slide plate is positioned between the RFID reader and the RFID tag and comprises a frequency selective surface that is substantially transparent to the RF signal.

Abstract: An antenna apparatus and method includes an orthogonal slot antenna which overcomes the limitations associated with RF choke between the adjacent slots through various feed techniques. A cavity backed cross-slot antenna includes a horizontal slot antenna, a vertical slot antenna sharing a center portion with the horizontal slot antenna, a first feed for the horizontal slot antenna, and a second feed for the vertical slot antenna, the first feed and the second feed provided to the shared center portion. Another cavity backed cross-slot antenna includes a horizontal slot antenna, a vertical slot antenna, the horizontal slot antenna and the vertical slot antenna share a center portion therebetween, a first feed feeding both halves of the horizontal slot antenna, and a second feed feeding both halves of the vertical slot antenna.

Abstract: A distributed comb tapped multiband antenna structure includes a PIFA-like antenna radiator having tap structures, and a counterpoise to the antenna radiator, wherein the tap structures include shunt connections to the counterpoise.

Abstract: A method and device enables improving a signal to noise ratio (SNR) of a backscatter signal received from a radio frequency identification (RFID) tag. The method includes generating a continuous wave (CW) carrier signal at the reader device (step 505). An amplitude modulation (AM) noise component of the CW carrier signal is then detected (step 510). The AM noise component is inverted to an inverted noise signal (step 515), and the inverted noise signal is summed with the CW carrier signal to provide an AM noise cancelled carrier signal (step 520). The AM noise cancelled carrier signal is then transmitted from an antenna of the reader device (step 525), and the backscatter signal is received at the reader device in response to transmission of the AM noise cancelled carrier signal (step 530).

Abstract: A method and apparatus for providing close proximity antenna measurement and tuning, includes a first receive-only antenna, a second antenna operable in a transmit mode, a tuning circuit coupled to the first antenna, a transmitter coupled to the second antenna, a receiver coupled to the first antenna, the receiver operable to measure a power into the first antenna delivered by a signal from the second antenna driven by the transmitter, and a processor coupled to the tuning circuit, transmitter, and receiver, the processor operable to step changes in the tuning circuit until a substantially maximum power of the signal is measured by the receiver.

Abstract: A mobile wireless communication device includes a circulators coupled between a respective communications arrangement and their antennas. Each circulator includes a coupled tuning network, wherein the tuning networks are operable to tune their circulators for maximum isolation from cross coupling between the power amplifiers within an operating frequency band of the respective communications arrangement.

Abstract: A method for improving RFID readers includes transmitting an outgoing RF signal to an antenna through a directional device, and generating a demodulated vector signal from an RF signal related to the RF signal received from the receiver. The method also includes setting the impedance of a controllable-variable-reflectance element with control-parameters from a memory circuit. The memory circuit includes a look up table having therein a corresponding relationship between the control-parameters and an error vector related to the demodulated vector signal.

Abstract: A method and apparatus for providing close proximity antenna measurement and tuning, includes a first receive-only antenna, a second antenna operable in a transmit mode, a tuning circuit coupled to the first antenna, a transmitter coupled to the second antenna, a receiver coupled to the first antenna, the receiver operable to measure a power into the first antenna delivered by a signal from the second antenna driven by the transmitter, and a processor coupled to the tuning circuit, transmitter, and receiver, the processor operable to step changes in the tuning circuit until a substantially maximum power of the signal is measured by the receiver.

Abstract: The present invention is directed to systems that use frequency selective surfaces (FSS) to aid in the operation of radio frequency identification (RFID) devices and products. In one embodiment, a system for interrogating radio frequency identification (RFID) tags includes a conveyor belt and an RFID reader. The conveyor belt has a first surface and a second surface. The first surface is configured to receive an item to which an RFID tag is affixed and the second surface is configured to slide on a metal slide plate. The RFID reader is configured to transmit instructions embodied in a radio frequency (RF) signal to the RFID tag, wherein the metal slide plate is positioned between the RFID reader and the RFID tag and comprises a frequency selective surface that is substantially transparent to the RF signal.

Abstract: An apparatus and method for augmenting an optical barcode scanner. The apparatus comprises an accessory module that includes an RFID reader, a body part attachable to the optical barcode scanner, and an interface connector for forming a communication link between the RFID reader and the optical barcode scanner when the interface connector is connected with the expansion port of the optical barcode scanner.

Abstract: A method and device enables improving a signal to noise ratio (SNR) of a backscatter signal received from a radio frequency identification (RFID) tag. The method includes generating a continuous wave (CW) carrier signal at the reader device (step 505). An amplitude modulation (AM) noise component of the CW carrier signal is then detected (step 510). The AM noise component is inverted to an inverted noise signal (step 515), and the inverted noise signal is summed with the CW carrier signal to provide an AM noise cancelled carrier signal (step 520). The AM noise cancelled carrier signal is then transmitted from an antenna of the reader device (step 525), and the backscatter signal is received at the reader device in response to transmission of the AM noise cancelled carrier signal (step 530).

Abstract: An apparatus and method for augmenting an optical barcode scanner. The apparatus comprises an accessory module that includes an RFID reader, a body part attachable to the optical barcode scanner, and an interface connector for forming a communication link between the RFID reader and the optical barcode scanner when the interface connector is connected with the expansion port of the optical barcode scanner.

Abstract: Methods, systems, and apparatuses for a reader transceiver circuit are described. The reader transceiver circuit incorporates a frequency generator, such as a surface acoustic wave (SAW) oscillator. A reader incorporating the reader transceiver circuit is configured to read a tag at very close range, including while being in contact with the tag. The transceiver can be coupled to various host devices in a variety of ways, including being located in a RFID reader (e.g., mobile or fixed position), a computing device, a barcode reader, etc. The transceiver can be located in an RFID module that is attachable to a host device, can be configured in the host device, or can be configured to communicate with the host device over a distance. The RFID module may include one or more antennas, such as a first antenna configured to receive a magnetic field component of an electromagnetic wave and a second antenna configured to receive an electric field component of an electromagnetic wave.

Abstract: The present invention is directed to systems that use frequency selective surfaces (FSS) to aid in the operation of radio frequency identification (RFID) devices and products. In one embodiment, a system for interrogating radio frequency identification (RFID) tags includes a conveyor belt and an RFID reader. The conveyor belt has a first surface and a second surface. The first surface is configured to receive an item to which an RFID tag is affixed and the second surface is configured to slide on a metal slide plate. The RFID reader is configured to transmit instructions embodied in a radio frequency (RF) signal to the RFID tag, wherein the metal slide plate is positioned between the RFID reader and the RFID tag and comprises a frequency selective surface that is substantially transparent to the RF signal.

Abstract: The present invention is directed to systems that use frequency selective surfaces (FSS) to aid in the operation of radio frequency identification (RFID) devices and products. In one embodiment, a system for interrogating radio frequency identification (RFID) tags includes a conveyor belt and an RFID reader. The conveyor belt has a first surface and a second surface. The first surface is configured to receive an item to which an RFID tag is affixed and the second surface is configured to slide on a metal slide plate. The RFID reader is configured to transmit instructions embodied in a radio frequency (RF) signal to the RFID tag, wherein the metal slide plate is positioned between the RFID reader and the RFID tag and comprises a frequency selective surface that is substantially transparent to the RF signal.