Abstract: A microstrip coupler is provided which includes an controlled capacitance bridge for improved directivity as compared to prior art controlled capacitance bridges. The novel controlled capacitance bridge provides the functionality of prior art wire or ribbon controlled capacitance bridges and also provides the necessary capacitance to compensate for the different phase velocities of odd and even modes in the transmission lines. Both the dimensions of the controlled capacitance bridge and the dimensions of an input microstrip conductor may be adjusted to provide the appropriate level of capacitance. In some embodiments, the controlled capacitance bridge connects segments of an input microstrip conductor. In other embodiments, the controlled capacitance bridge connects microstrip conductors which are configured to couple an input signal from an input microstrip conductor.

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 system and method of pilot tone reuse.

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: A system and method for reducing or eliminating signal amplitudes near or crossing zero is disclosed. Communication systems and methods employing a single carrier or multiple carriers and employing reduction of signal amplitudes near or crossing zero are also disclosed. Communication systems and methods using envelope elimination and restoration amplification and reduction of amplitudes near or crossing zero are also disclosed.

Abstract: A group delay adjusting circuit. The group delay adjusting circuit comprises an electronically adjustable variable capacitance, and an electronically variable virtual inductor coupled in parallel to the electronically variable capacitance at a node.

Abstract: A feed forward amplifier employing high efficiency main and/or error amplifiers with amplifier devices biased in a lower bias class. Small signal nonlinearities in the gain response of the amplifier devices are compensated by a small signal gain adjustment circuit. The resulting gain response is substantially linear over the entire usable range of RF input power.

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 allowing for the inexpensive automated construction of interconnections between circuit boards is provided. According to the present invention, printed circuit pins are inserted in a circuit board from the top (component side). Provided the heads of the pins are thin enough to lie beneath a solder stencil, the pins may be pre-installed on the circuit board and solder applied to the pins at the same time solder is applied to other regions of the board. Thus, known surface mount techniques may be employed to form solder connections between the pins and conductive traces on the circuit board, which facilitates the automation of the previously manual operation of soldering the printed circuit pins separately.

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 microstrip coupler is provided which includes an controlled capacitance bridge for improved directivity as compared to prior art controlled capacitance bridges. The novel controlled capacitance bridge provides the functionality of prior art wire or ribbon controlled capacitance bridges and also provides the necessary capacitance to compensate for the different phase velocities of odd and even modes in the transmission lines. Both the dimensions of the controlled capacitance bridge and the dimensions of an input microstrip conductor may be adjusted to provide the appropriate level of capacitance. In some embodiments, the controlled capacitance bridge connects segments of an input microstrip conductor. In other embodiments, the controlled capacitance bridge connects microstrip conductors which are configured to couple an input signal from an input microstrip conductor.

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.