Abstract: A RFID system, according to one embodiment, includes: a plurality of radiating elements, a transmission line, and power dividers coupling the plurality of radiating elements to the transmission line. The power dividers are coupled along the transmission line, and are configured such that they provide an equal distribution of power between each of the plurality of radiating elements. Moreover, an input impedance of each of the power dividers is about equal to an impedance of the transmission line.

Abstract: A logic inverter with over-current protection, according to one embodiment, includes: a transistor, an input signal line coupled to a gate terminal of the transistor or a base region of the transistor, an output signal line coupled to a drain terminal of the transistor or a collector region of the transistor, a power supply line coupled to the drain terminal of the transistor or a collector region of the transistor, a pull up resistor between a power supply and one of: the drain terminal of the transistor and the collector region of the transistor, and a feedback resistor between ground and one of: a source terminal of the transistor and an emitter region of the transistor. Other systems, methods, and computer program products are described in additional embodiments.

Abstract: A device according to one embodiment includes a variable-capacitor-tuned isolation tuning circuit having a directional coupler having an input port, an output port, an isolation port, and a coupling port. The variable-capacitor-tuned isolation tuning circuit also has and a tunable capacitor coupled in shunt to the coupling port of the directional coupler.

Abstract: A Radio Frequency Identification (RFID) system according to one embodiment includes a chain of radiating elements; a transmission line; and power dividers coupled along the transmission line, the power dividers coupling the transmission line to each of the radiating elements, the power dividers being configured such that each radiating element receives about a same amount of power from the transmission line.

Abstract: A Radio Frequency Identification (RFID) tag according to one embodiment includes a radiating element lying primarily along a plane, a conductive loop lying along a plane oriented about perpendicular to the plane of the radiating element, and an integrated circuit coupled to the conductive loop.

Abstract: A logic inverter with over-current protection according to one embodiment includes a transistor, an input signal line coupled to a gate terminal or base region of the transistor, an output signal line coupled to a drain terminal or collector region of the transistor, a power supply line coupled to the drain terminal or collector region of the transistor, and a feedback resistor between a source terminal or emitter region of the transistor and ground.

Abstract: A logic inverter with over-current protection according to one embodiment includes a transistor, an input signal line coupled to a gate terminal or base region of the transistor, an output signal line coupled to a drain terminal or collector region of the transistor, a power supply line coupled to the drain terminal or collector region of the transistor, and a feedback resistor between a source terminal or emitter region of the transistor and ground.

Abstract: A Radio Frequency Identification (RFID) system according to one embodiment includes a chain of radiating elements; a transmission line; and power dividers coupled along the transmission line, the power dividers coupling the transmission line to each of the radiating elements, the power dividers being configured such that each radiating element receives about a same amount of power from the transmission line.

Abstract: A Radio Frequency Identification (RFID) tag according to one embodiment includes a radiating element lying primarily along a plane, a conductive loop lying along a plane oriented about perpendicular to the plane of the radiating element, and an integrated circuit coupled to the conductive loop.

Abstract: A device according to one embodiment includes a variable-capacitor-tuned isolation tuning circuit having a directional coupler having an input port, an output port, an isolation port, and a coupling port. The variable-capacitor-tuned isolation tuning circuit also has and a tunable capacitor coupled in shunt to the coupling port of the directional coupler.

Abstract: According to one embodiment, an antenna comprises a plurality of elongated side radiating elements having longitudinal axes oriented at angles of between about 10° and about 80° from a line perpendicular to an imaginary base plane extending across ends of the side radiating elements, and a cavity positioned between the side radiating elements defined by at least one non-radio frequency-transparent sidewall. In another embodiment, a system comprises a plurality of elongated side radiating elements each lying along a unique side plane and having longitudinal axes oriented at angles of between about 10° and about 80° from a line perpendicular to an imaginary base plane extending across ends of the side radiating elements, and a cavity being positioned between the side radiating elements defined by at least one non-radio frequency-transparent sidewall, wherein the at least one sidewall has sides each lying along a plane about parallel to the unique side plane.

Abstract: According to one embodiment, an antenna comprises a plurality of elongated side radiating elements having longitudinal axes oriented at angles of between about 10 and about 80 degrees from a line perpendicular to an imaginary base plane extending across ends of the side radiating elements. In another embodiment, an antenna comprises a plurality of elongated side radiating elements each lying along a unique side plane and having longitudinal axes oriented at angles of between about 10 and about 80 degrees from a line perpendicular to an imaginary base plane extending across ends of the side radiating elements and a plurality of top radiating elements each electrically coupled to an associated one of the side radiating elements and lying along a top plane. Of course, many other systems and antennas according to other embodiments are included in the invention.

Abstract: A memory system according to one embodiment includes a plurality of content addressable word decoders, and memory cells associated with each of the word decoders. A memory system according to another embodiment includes a word decoder storing an identifier which is a subset of a memory address, the word decoder being responsive to a match of the identifier and an incoming subset of the memory address. A memory system according to yet another embodiment includes a word decoder having more than sixteen address line inputs. A memory system according to a further embodiment includes a word decoder array having fewer word decoders than combinations of memory addresses. Methods are also provided.

Abstract: A circular polarized antenna having an electrically conductive element having a generally annular outer portion and first and second inner members coupled to the outer portion. A ground shield is spaced from the element, the ground shield providing an effective ground plane. A dielectric material is positioned between the element and at least a portion of the ground shield.

Abstract: An RFID transponder programming device uses a strip transmission line to generate a constrained electromagnetic field for programming RFID transponders is featured. The programmer minimizes electromagnetic fields outside of the programming device, and keeps other blank transponders from being wrongly programmed or erased. The transmission line may either be terminated or unterminated. The characteristic impedance of the strip transmission line may be 50 ohms or any other impedance. Since the strip transmission line is terminated in its own characteristic impedance, the programmer is inherently wideband and able to work with frequencies from 433 MHz to 869 MHz, 902 to 928 MHz, and 2400 to 2485 MHz, all in the same unit.

Abstract: The present invention features an RFID smart shelf reader capable of working with a wide range of antenna types and numbers. The smart shelf reader readily accommodates and accurately reads a diverse range of package shapes, sizes, and contents. Multiple tags in close proximity to one another are accurately read by the smart shelf reader. The reader includes features for optimizing its own interface by periodically recalibrating itself to the current antenna load characteristics caused by varying external conditions, primarily in the type, number, and position of merchandise items on the shelf proximate at least one of the antennas. An external I/O interface is provided for communication with a remote controller.

Abstract: There is provided an RFID transceiver, typically in the form of a prox-wafer. The transceiver is suitable for lamination or encapsulation into newly manufactured identification (ID) badges and similar articles. These ID badges are suitable for identifying and/or authenticating a person or object when used in conjunction with an RFID identification system. The proximity badges formed using the RFID transceivers are superior to conventional magnetic stripe, bar code, or “smart chip” badges because no direct contact with a badge reader is required and the element containing the identification code is not easily corrupted.

Abstract: There is provided an RF-powered, RFID transponder operable in either a high frequency or low frequency band. The transponder utilizes an EEPROM which may be programmed. The high voltage required for writing (i.e., programming) the EEPROM is provided by a unique circuit which eliminates the need for voltage multiplying circuits which typically use large, high value capacitors which usually occupy large amounts of chip real estate. It is estimated that the write voltage circuit reduces chip real estate requirements by approximately 13%.

Abstract: The present invention features an improved radio-frequency identification (RFID) reader which operates with a low power consumption and which may tolerate a wide fluctuation in input voltages. The RFID reader is housed so that the influence of its physical surroundings, especially metallic objects, on system performance is minimized. A pre-compensation metal plate is used to stabilize the self-resonant frequency of the reader, even in the presence of large metal masses. The pre-compensation plate may be formed from aluminum or another non-ferrous material or, for long-range RFID readers, from ferrite or another similar, high magnetically permeable material. In addition, the RFID reader features improved sensitivity so that the effective operating distance is maximized. Also, the operating frequency is dynamically controlled in discrete steps of 10 Hz or less so that the effects of component parameter drift, temperature change, or other external factors are minimized.

Abstract: The present invention features an improved radio frequency identification (RFID) reader which operates with a low power consumption and which may tolerate a wide fluctuation in input voltages. The RFID reader is housed so that the influence of its physical surroundings, especially metallic objects, on system performance is minimized. A pre-compensation metal plate is used to stabilize the self-resonant frequency of the reader, even in the presence of large metal masses. The pre-compensation plate may be formed from aluminum or another non-ferrous material or, for long-range RFID readers, from ferrite or another similar, high magnetically permeable material. In addition, the RFID reader features improved sensitivity so that the effective operating distance is maximized. Also, the operating frequency is dynamically controlled in discrete steps of 10 Hz or less so that the effects of component parameter drift, temperature change, or other external factors are minimized.