Abstract: A system and method for signal peak reduction in a multiple carrier communication system where the individual carriers are produced from input symbols that are filtered to reduce individual carrier bandwidths, offset in frequency, and combined into an output signal. A multiple carrier peak reduction unit is provided which modifies the input carrier symbols so that the combined output signal does not exceed a predetermined peak limit value. The multiple carrier peak reduction unit includes filter predictors that predict the effect of each channel filter on that carriers input symbols by using filter coefficient values corresponding to the impulse response function of each filter. The filter predictor outputs are then phase shifted, in correspondence to frequency offsets provided for in multiple carrier signal generation, and combined to produce a prediction of the combined signal output which is then processed to determine the corrections required to the individual channel symbol inputs.

Abstract: A system and method for signal peak reduction in a spread spectrum communication system of the type including a filter for limiting signal bandwidth of symbols transmitted from the system. A signal peak reduction unit is provided before the filter that includes a filter predictor that predicts the effect of the filter on input symbols by using filter coefficient values corresponding to the filter impulse response function. Input symbols that are predicted to cause the output signal to exceed a predetermined peak limit value are adjusted. Several examples of suitable algorithms for calculating the necessary peak reduction to be applied to the input symbols are disclosed. The peak reduction unit provides adjusted symbols to the filter for processing and communication system output.

Abstract: A apparatus and a method of isolating two cavities within an electrical equipment by using a S-shaped plate having fingers on opposite sides such that the S-shaped plate may be installed between two open ended inner walls.

Abstract: A delamination resistant electronics module assembly includes a printed circuit board layer coupled to a pallet via a cured epoxy preform. The preform may include conductive epoxy, or non-conductive epoxy with conductive traces. Component wells are collectively formed by the preform and PCB layer for placement of heat generating components, such as RF components. Methods of manufacturing module assemblies include curing the epoxy preform by applying a predetermined elevated pressure and heat to a sub-assembly of the pallet, preform layer, and PCB layer.

Abstract: An electronics assembly incorporating an interconnect includes a conductive gasket disposed between a first printed circuit board and a second printed circuit board. The gasket surrounds, and thereby shields, the interconnect while providing an RF ground connection between the two boards with a controlled RF impedance. The second printed circuit board may serve as a connector board for a plurality of modules, or other printed circuit boards, to be coupled thereto. Each module is individually covered with a separate lid. Methods for manufacturing and assembling structures according to the invention are also provided.

Abstract: A heat sink assembly for an electronics assembly, such as an RF power amplifier, includes a pallet, a fin structure, and a hollow base separate from the fin structure. The fin structure may be an integral curved sheet or a modular apparatus comprising a plurality of inverted U-shaped fin modules. Top horizontal walls of the fin structure directly contact a bottom surface of the pallet. Vertical fins of the fin structure are inserted through the slots of the base. The pallet, fin structure and base are coupled together such that the upper surface of the base applies load to the contact portions of the fin structure sandwiched between the base and the pallet. Methods for assembling a power amplifier and manufacturing a heat sink assembly are also provided.

Abstract: An amplifier assembly having a grounded mode wall is disclosed. The mode wall is supported in a substantially serpentine slot in an amplifier substrate. The serpentine slot supports and grounds the mode wall at a plurality of points of contact. The points of contact are spaced apart at roughly ¼ the wavelength or less of EMI emissions of the amplifier circuitry.

Abstract: An RF pallet ground comprises overhangs disposed at opposite ends. Each overhang includes a downwardly protruding ledge and a notch defined in a bottom surface of the pallet. The ledges and notches extend from one side of the pallet to the other. The ledge provides a positive connection directly to ground. The ledge has a length shorter than the length of the main body of the pallet. Fasteners are positioned on either side of an RF trace on the pallet, allowing positive pressure to be applied to the ground through the ledge.

Abstract: A heat sink assembly for an electronics assembly, such as an RF power amplifier, includes a pallet, a fin structure, and a hollow base separate from the fin structure. The fin structure may be an integral curved sheet or a modular apparatus comprising a plurality of inverted U-shaped fin modules. Top horizontal walls of the fin structure directly contact a bottom surface of the pallet. Vertical fins of the fin structure are inserted through the slots of the base. The pallet, fin structure and base are coupled together such that the upper surface of the base applies load to the contact portions of the fin structure sandwiched between the base and the pallet. Methods for assembling a power amplifier and manufacturing a heat sink assembly are also provided.

Abstract: An apparatus for either combining a plurality of high frequency RF signal inputs or splitting a single RF frequency input into a plurality of RF signal outputs employs a switchable combining/splitting section and a switchable matching section. The switchable combining/splitting section operates to either combine the RF signal inputs to a common summed output or to take a matched input and to split it into a plurality of outputs. The matching section operates to switchably match the impedance presented by the combining/splitting section to achieve a minimum or zero insertion loss through the apparatus.

Abstract: Systems and methods are taught whereby amplification of narrowband signals may be accomplished by linear power amplifiers requiring the presence of a communicated broadband signal in order to make internal adjustments necessary for linear operation. A preferred embodiment is described utilizing an input of a distributed amplifier assembly unused by the signals of interest in order to inject an emulated CDMA tone operable as a pilot tone for use by the linear power amplifiers.

Abstract: The invention relates to an amplifier arrangement for amplifying an input using a distorting main power amplifier such as one operating as a class AB amplifier. The method and apparatus add to the input signal to the main amplifier a predistortion signal intended to compensate for the distortion added by the main power amplifier. In accordance with the invention, the input to the predistortion circuit is modified by measuring peak-to-peak signal values of the distortion in the output of the main power amplifier. The peak-to-peak values are measured in a signal derived by comparing an output derived from the main amplifier with an output derived from the input signal. A digitally controlled processor iteratively modifies various phase and gain controls to adjust the output of the amplifier.

Abstract: The invention relates to a method and apparatus for reducing the distortion output of an amplifier used with an RF signal. The method and apparatus typically modify the distortion of the amplifier to reduce it, by detecting cross-modulation components modulated onto a continuous wave, low level, pilot signal injected at the input of the amplifier system. The circuitry detects the cross-modulation components and provides correction signals in response thereto.

Abstract: The invention relates to a low cost feed forward RF power amplifier arrangement for amplifying an RF input signal using a main power amplifier operating as a Class AB amplifier. The method and apparatus modify the input signal to the main amplifier to compensate for the distortion added by the main power amplifier. The circuit provides for injecting a pilot signal prior to the Class AB amplifier and adjusting the correction circuitry of the amplifier based on a quadrature modulated, chopped derivative of the injected pilot signal.

Abstract: A method and apparatus reduce the out-of-band frequency components of an RF amplified signal, preferably a CDMA signal, which has a carrier frequency which is not known in advance. The apparatus and method feature locating the frequency of the incoming signal by examining an RF output signal having both in-band frequency components and out-of-band frequency components. Typically the output signal is generated using a high-power, Class A/B amplifier. Once the frequency of the carrier has been determined, the out-of-band components are used to generate control signals which, in, for example, a feedback or feedforward circuitry, reduce the energy of the out-of-band signals and thereby provide a more linear amplifier transfer function.

Abstract: A method and apparatus for reducing out-of-band frequency components of an RF amplified input signal, the amplified signal having both in-band frequency components and out-of-band frequency components, employ a feedforward network in which a microprocessor can sweep a frequency generator output connected to a mixer, the other input of the mixer being the amplified output, to find the carrier frequency of the input signal, and thereafter modify or control the feedforward circuit to reduce out-of-band frequency component energies in a particular manner. For example, gain and phase of a variable gain-phase network in a feedforward circuit structure can be modified for reducing the out-of-band frequency component energy.

Abstract: A method and apparatus for reducing out-of-band frequency components of an RF signal having a carrier frequency which is not known in advance employ a control signal to vary adjustable bias parameters of the circuit. In particular embodiments, the RF signal is generated from a MOSFET power amplifier, which introduces distortion components into its output signal. Bias parameters of the MOSFET amplifier can be varied to reduce out-of-band frequency components, that is, out-of-band distortion. In addition, other elements of the network can be controlled by varying bias parameters, for example, a predistorter.

Abstract: An apparatus and method measure the energy in frequency bands of an amplified signal, the amplified signal being an amplified version of an RF received input signal, where the received signal has an allocated frequency bandwidth and carrier frequency. The carrier frequency, however, is not known in advance of receipt; and therefore, the apparatus and method provide structure and methodology for finding the carrier and then reducing the out-of-band frequency components of the amplified signal. The apparatus features a mixer configured as a four quadrant multiplier biased into a linear operating region. The mixer receives both the received signal and the amplified signal, and produces as its output a baseband signal. Various detection mechanisms can be used to determine the distortion correction control signals based upon the energy in portions of the amplified signal offset from the carrier signal. In a preferred embodiment, the mixer is a Gilbert Cell mixer and the received signal is a CDMA signal.

Abstract: For use with RF circuitry in which a DC bias circuit provides bias voltage is provided to impedance-matched circuitry, a structure is provided, in which a dielectric member, having a high dielectric constant, is selectively placed adjacent to a bias feed line coupled between the DC bias circuit and the remainder of the circuitry, to maintain high RF impedance while reducing impedance at lower frequencies. The invention has particular applicability to RF amplifiers, to be used for amplifying modulated carriers, such as video signals made up of an RF carrier and a lower-frequency modulation. Where the carrier has a predetermined wavelength, the physical length of the bias feed line and the dielectric constant of the dielectric member are chosen such that an effective length of the bias feed line is a quarter of the wavelength of the carrier.

Abstract: The invention relates to an amplifier arrangement for amplifying an input using a distorting main power amplifier such as one operating as a class AB amplifier. The method and apparatus add to the input signal to the main amplifier a predistortion signal intended to compensate for the distortion added by the main power amplifier. In accordance with the invention, the predistortion signals can be dynamically modified to improve, substantially, at least the third order intermodulation components in the output of the power amplifier. A digitally controlled processor iteratively modifies various phase and gain controls to adjust the output of the amplifier. Different gain and phase control lines are iteratively updated at different rates.