Abstract: A feed forward RF power amplifier which provides both high efficiency and minimal distortion in broad bandwidth RF applications. The feed forward power amplifier includes a main amplifier biased to provide high efficiency and an error amplifier biased to provide highly linear operation through substantially the entire operating range. Signal peaks which introduce distortion components at the main amplifier output are cancelled by the linear operation of the error amplifier.

Abstract: A dynamic bias switching circuit is provided that includes a switching unit for switching between a first signal level and a second signal level based on a signal envelope of an input signal to an amplifier.

Abstract: An RF power amplifier with amplifier stage failure detection comprises an amplifier input for receiving an RF signal to be amplified, an amplifier output for outputting an amplified RF signal, a plurality of separate amplifier stages coupled between the amplifier input and amplifier output so as to cumulatively provide a desired amplifier gain to the input RF signal, and means for detecting amplifier stage failure by providing a pilot tone separately to the amplifier stages based on a separate timing for each stage and detecting pilot tones output from the stages based on the timing.

Abstract: A surface mount technology (“SMT”) apparatus for use in routing radio frequencies (“RF”) between cavities that require a high level of isolation on a single printed circuit board (“PCB”). The SMT part is attached to the PCB over a stripline-ready trace which transitions to microstrip before and after the SMT stripline part to maintain consistent characteristic impedance. When presented with a high isolation need between two cavities using microstrip transmission lines, the proposed stripline SMT apparatus under the isolation wall will tend to provide the necessary isolation. The present invention provides a repeatable and reliable interconnect while improving the electrical match between the two cavities. Furthermore, the invention removes the costs associated with manually forming and soldering cables between PCBs.

Abstract: A printed circuit board (PCB) assembly comprising a PCB having a top circuitry layer and a bottom layer with a hole through the PCB, a component, and a pallet. The printed circuit board manufactured by a method including forming a hole through the top circuitry layer and the bottom layer, attaching the bottom layer to a pallet, placing the component in the hole, and soldering the component to the top circuitry layer and to the pallet.

Abstract: A method for supporting a wall-like structure by forming a serpentine shaped slot on a substantially planar surface. The serpentine slot includes an area of central clearance such that a wall-like structure having a width narrower than the width of the serpentine slot can be inserted into the area of central clearance and be supported by the inner sides of the serpentine slot.

Abstract: An RF power amplifier with amplifier stage failure detection comprises an amplifier input for receiving an RF signal to be amplified, an amplifier output for outputting an amplified RF signal, a plurality of separate amplifier stages coupled between the amplifier input and amplifier output so as to cumulatively provide a desired amplifier gain to the input RF signal, and means for detecting amplifier stage failure by providing a pilot tone to the amplifier stages, duty cycling the amplifier stages based on a separate timing for each stage and detecting the pilot tone output from the stages based on the timing.

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 A/B 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 delayed version of the input signal, through a fixed gain-phase circuity, at a point whereby the resulting signal is amplified by the error amplifier of the second loop. 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.

Abstract: An apparatus and method reduce out-of-band frequency components of an amplified, multichannel RF signal able to have at least two frequency bandwidth limited signal channels, each channel having a respective carrier frequency which is not known in advance. The channels can, for example, be dedicated to CDMA signals. Each channel of the amplified RF signal has both in-band frequency components and out-of-band frequency components. The apparatus and method feature a network for amplifying an input signal for producing the amplified RF signal, the network having adjustable electrical characteristics, and a control system connected to the network for locating a frequency within the bandwidth of one of the channels of the amplified RF signal and for detecting energy in the out-of-band frequency components for the one located channel for producing control signals relating to the energy in that one channel.

Abstract: A low cost radio frequency interference filter assembly comprises a multiple layer structure including a middle trace layer disposed between an upper ground layer and lower ground layer. Non-conductive insulation layers are disposed between the middle trace layer and the upper and lower ground layers. The upper layer includes input contacts, signal contacts, and capacitors which are coupled to the signal contacts and an upper grounded substrate. The middle trace layer includes a grounded substrate and trace lines which are coupled to the signal contacts of the upper layer by signal vias. The lower layer includes a grounded substrate. Ground vias are formed through the insulation layers to couple the middle grounded substrate to the upper and lower grounded substrates. The filter assembly may be formed as an integral projection of a printed circuit board assembly.

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.