Abstract: A patch antenna in accordance with the present invention comprises a patch optionally surrounded by a top ground plane, a feed line disposed beneath the patch and separated therefrom by a thin substrate, a middle ground plane separated from the feed line by another thin substrate, and a bottom ground plane disposed beneath the middle ground plane and preferably separated therefrom by foam or another lightweight dielectric layer. Conductive vias run between the top ground plane and the middle ground plane as well as from the middle ground plane to the bottom ground plane. The middle ground plane is essentially annular, defining an opening in the middle thereof, such that there is a dielectric cavity beneath the patch and the feed line in the space defined by the bottom ground plane, the middle ground plane and the vias that run between the middle ground plane and the bottom ground plane. This cavity can be filled with low cost, low weight foam, rather than the heavier, more costly conventional substrates.

Abstract: An antenna system for a radio frequency identification system comprising: (a) a base; (b) a first patch antenna disposed on the base and having a circular polarization and adapted to convert between electrical signals and electromagnetic fields; and (c) a second patch antenna disposed on the base and having a circular polarization and adapted to convert between electrical signals and electromagnetic fields, the second antenna being disposed at a distance from the first antenna to define a region between the first and the antenna, the second patch antenna being positioned relative to the first patch antenna such that the electromagnetic fields of the two antennas are substantially opposing in the region.

Abstract: A phase locked loop includes a buffer that synchronizes the transmission of the new count value to the completion of the previous count to avoid errors caused by dithering. The buffer is connected to a count input of the counter and transmits the new count upon receipt of the carryout signal from the counter. Alternatively, the transmission of the new value of N from the buffer is delayed after receipt by the buffer of a carryout signal from the counter. In another embodiment, a delayed version of the carryout signal is used to trigger the buffer to transmit the new count value to the counter. In another feature, a buffer synchronizes phase data to a reference signal before inputting it to a digital modulator of the phase locked loop.

Abstract: A security system for a digital trunked radio system having a digital control channel and a plurality of working channels, wherein said working channels are assigned for temporary use of individual radio units by digital control signals transmitted over said control channel, said control channel carrying digital control signals between a base site and said radio units, comprising a digital key, said key used to limit access to the system equipment and system control channel transmissions.

Abstract: An apparatus and method for transmitting signal, the apparatus comprising a front end telecommunications module including a power amplifier, a matching circuit coupled to the power amplifier, and a filter coupled to the matching circuit, such that a signal received by the power amplifier is transmitted to the filter through the matching circuit. The telecommunications module provides quad-band capability in a compact design.

Abstract: A method and apparatus for generating short electronic pulses using a modified differential trigger that is partly an analogue sinusoidal voltage and partly a selectable, DC voltage. The differential trigger is applied to a differential base band pulse generator having a NAND gate and AND gate. The trigger is applied to both NAND inputs and to one AND input. The NAND output is applied the other AND input. Such a circuit is an OFF state for all input states. However, as the input switches state, the NAND gate delay causes the AND gate to be ON briefly, generating a short pulse. The timing of this pulse can be controlled by varying the constant DC voltage. By using fast switching SiGe CML gates, short pulses with a controllable time off-set can be generated that are suitable for use in automotive radar applications, using only sub-GHz clocks.

Abstract: A pulsed radar that uses a single sideband pulsed signal for determining a distance to a target. The radar has twice the target resolution of a conventional pulsed radar using the same bandwidth signal. The single sideband pulsed signal may be produced by mixing a base-band pulsed signal with a radio frequency (RF) carrier frequency and then filtering the resultant amplitude modulated signal to suppress either the upper or the lower sideband signal. Because only one sideband is used, the pulse occupies half the bandwidth that it would in a conventional pulsed radar. For a given bandwidth, the single sideband radar, therefore, has twice the target resolution of a conventional pulsed radar system. The single sideband signal's shape must, however, be preserved during amplification to avoid reintroduction of the suppressed sideband, so highly linear power amplifiers must be used to boost the strength of the signal before transmission.

Abstract: A multi-layer cross connect having high isolation between signal channels, the multi-layer cross connect comprising: (a) a multi-layer circuit board having a top and bottom orientation and comprising at least a bottom layer and one or more upper layers; (b) a plurality of microstrip launches along the perimeter of the bottom layer; (c) a plurality of striplines on the bottom layer, each stripline being connected to one and only one microstrip launch and comprising a transformer for lowering its impedance and thereby increasing its width, the striplines comprising first striplines and second striplines; (d) a plurality of transition vias, each transition via conductively coupling each of the second striplines to a stripline on an upper layer; and (e) a combiner on each layer for combining signals from multiple striplines to a common stripline.

Abstract: An apparatus and method for biasing at least one transistor of a Radio Frequency Digital to Analog Converter (RFDAC). The apparatus including a direct base current injection circuit for injecting a DC current waveform directly into a base terminal of the transistor.

Abstract: Apparatus, methods and articles of manufacture for multiband transmitter power amplification are provided wherein one or more amplifying devices, of which at least one may be one or more current sources, have impedances matched for different input and output frequencies by way of various impedance matching circuits.

Abstract: An apparatus and method for amplifying a radiofrequency signal using a main Digital to Analog Converter (RFDAC) and a subordinate Digital to Analog Converter (Sub-DAC). The main RFDAC provides a first portion of a N-bit digital output, which specifies the amplification level of the radiofrequency signal, and the sub-DAC provides a second portion of the N-bit digital word. Together, the main RFDAC and the Sub-DAC convert a complete N-bit digital word, where N specifies the resolution of the output radiofrequency signal.

Abstract: A cross-coupled dielectric resonator circuit. Resonator circuits in accordance with the invention may be used to build low-loss compact filters, oscillators, and other circuits, particularly microwave circuits. The resonators are arranged relatively to each other within an enclosure in a very efficient and compact design that enhances adjustability and coupling between adjacent resonators and the cross-coupling of alternate resonators.

Abstract: A ferrite circulator having integrated alignment members and a method for aligning a ferrite element within a ferrite circulator are provided. The ferrite circulator includes a ferrite circulator housing having a body for receiving at least one ferrite element therein. The ferrite circulator housing further includes a plurality of alignment members positioned and configured to maintain the alignment of the at least one ferrite element in an alignment region defined by the plurality of alignment members.

Abstract: A system and method to wirelessly communicate information between traffic control signs and vehicles are provided. The method includes wirelessly communicating traffic control information from a traffic control sign to a vehicle and wirelessly communicating vehicle information from the vehicle to the traffic control sign.

Abstract: A package for a light emitting diode (LED) including an electrically insulating substrate layer, a non-conductive layer disposed on the electrically insulating substrate layer, and a reflector layer disposed on the non-conductive layer. The electrically insulating layer includes metallized portions for coupling a light emitting diode thereto.

Abstract: An amplifier circuit includes a calibration circuit with a controllable circuit element such as a digital resistor. One or more properties of the controllable circuit element (e.g., the resistance in a digital resistor) is varied by a digital calibration word such that the voltage drop across the resistor matches a reference voltage. The calibration word is also used to control the resistance of a transistor that forms a part of a power amplifier to compensate for temperature and process variations. The amplifier may be a switching power amplifier, and the transistor may be a segmented transistor with the width (and hence the channel resistance) controlled by the digital calibration word.

Abstract: A radar system having a beamless emission signature is described. In one implementation, the radar system includes a transmission system and a receiver system. The transmission system is configured to transmit a pattern comprising a plurality of radar signals having different frequencies simultaneously. The receiver system is configured to receive a reflection of the pattern and combine the plurality of radar signals into a composite waveform forming an image of a target.

Abstract: The invention relates to a system for electromagnetic processing of an input wave involving receiving a modified signal derived from two or more signals that represent the input wave when combined; and regulating the modified signal using at least one characteristic of the two or more signals. Embodiments of the invention may utilize in-phase and quadrature phase signals, where the magnitude portion of the signals may be used for regulating the modified signal. The modified signal may be created by modulating a characteristic of the I, Q signals, such as their sign, with an RF or other frequency carrier wave.

Abstract: An apparatus and method for transmitting signal, the apparatus comprising a front end telecommunications module including a power amplifier, a matching circuit coupled to the power amplifier, and a filter coupled to the matching circuit, such that a signal received by the power amplifier is transmitted to the filter through the matching circuit. The telecommunications module provides quad-band capability in a compact design.

Abstract: A receiver circuit including a differential amplifier and at least one common mode feedback circuit coupled to the differential amplifier for providing a control current to the differential amplifier for regulating a common mode voltage of the differential amplifier. The receiver circuit provides integration and sampling on an input signal, and may be used as a portion of a sensor circuit.