Abstract: Various methods and apparatus for operating an outphasing amplifier comprising first and second amplifiers to achieve wider bandwidth and higher efficiency of operation of the outphasing amplifier are disclosed.

Abstract: An outphasing amplifier apparatus and method is disclosed that controls pulse width modulation and/or pulse height modulation to improve power-added-efficiency performance and/or compensate for errors caused by quantized pulse position settings is provided herein.

Abstract: Circuits and techniques to linearize the operation of an RF power amplifier are described. A linearizer circuit may include a non-amplification signal path which includes a delay line and an amplification signal path which includes at least one amplifier stage. In some embodiments, the amplification signal path may include an odd number of amplification stages. The linearizer may be used to precondition an input signal of an RF power amplifier in a manner that improves the overall linearity of operation.

Abstract: A pulse width modulated/pulse modulated PWM/PPM power amplification circuit includes a load modulation circuit coupled between an output of the amplification circuit and a load. In one embodiment, the load modulation circuit comprises a plurality of capacitor elements switchably coupled such that in response to a control signal provided the load modulation circuit presents one of a plurality of different capacitance values at a terminal thereof. By changing capacitance values associated with the plurality of capacitor elements in accordance with the output of the amplification circuit and the load, improved (and “optimum”) power levels that exhibit a desired (and best) efficiency can be selected. Such results in an amplification circuit having an efficiency level which is relatively high compare with efficiency levels of conventional amplifier circuits over a wide dynamic range of output power.

Abstract: An RF circuit includes a balun circuit comprised of a coaxial cable having a desired characteristic impedance and having a first port coupled to a first port of said RF circuit and a second port and a transformer circuit having a first port coupled to the second port of the balun. The transformer circuit is comprised of a pair of coaxial cables, each having a desired characteristic impedance and each having a ferrite coupled thereto. The interconnects between center conductors and outer conductors in the transformer are made symmetrical such that a resonance with a frequency determined by the inductance and capacitance of the coaxial cables does not occur, preventing any nulls in an insertion loss characteristic of the RF circuit. The ferrite is selected to act as a circuit element having an impedance characteristic which is higher than the impedance characteristic of the coaxial cable.

Abstract: Circuits and techniques to linearize the operation of an RF power amplifier are described. A linearizer circuit may include a non-amplification signal path which includes a delay line and an amplification signal path which includes at least one amplifier stage. In some embodiments, the amplification signal path may include an odd number of amplification stages. The linearizer may be used to precondition an input signal of an RF power amplifier in a manner that improves the overall linearity of operation.

Abstract: A power amplification system includes a linearizer circuit feeding a power amplifier to linearize the operation of the power amplifier. The linearizer circuit may shape the input signal of the power amplifier in a manner that complements the output power versus input power characteristic of the power amplifier. In some embodiments, the linearizer may increase the relative magnitude of higher power portions of the input signal while decreasing the relative magnitude of lower power portions of the input signal to provide an overall increase in the linearity of the power amplification system. The power amplifier may include a Doherty amplifier in some implementations.

Abstract: An RF circuit includes a balun circuit comprised of a coaxial cable having a desired characteristic impedance and having a first port coupled to a first port of said RF circuit and a second port and a transformer circuit having a first port coupled to the second port of the balun. The transformer circuit is comprised of a pair of coaxial cables, each having a desired characteristic impedance and each having a ferrite coupled thereto. The interconnects between center conductors and outer conductors in the transformer are made symmetrical such that a resonance with a frequency determined by the inductance and capacitance of the coaxial cables does not occur, preventing any nulls in an insertion loss characteristic of the RF circuit. The ferrite is selected to act as a circuit element having an impedance characteristic which is higher than the impedance characteristic of the coaxial cable.

Abstract: An amplifier circuit includes a pair of amplifying devices, a first balun coupled between an input port of the amplifier circuit and RF input ports of the pair of amplifying devices and a second balun coupled between RF output ports of the pair of amplifying devices and an output port of the amplifier circuit wherein the first and second baluns are configured such that the amplifier circuit operates under open condition for signals at a second harmonic frequency even when the second harmonic frequency is within an operating frequency band of a fundamental frequency of the amplifier circuit. In one embodiment, the amplifier circuit includes a bypass circuit which selectively couples balun ports to ground such that in response to a first control signal, the amplifier circuit operates in an amplifying mode and in response to a second control signal, the amplifier circuit operates in a bypass mode.

Abstract: An amplifier circuit includes a pair of amplifying devices, a first balun coupled between an input port of the amplifier circuit and RF input ports of the pair of amplifying devices and a second balun coupled between RF output ports of the pair of amplifying devices and an output port of the amplifier circuit wherein the first and second baluns are configured such that the amplifier circuit operates under open condition for signals at a second harmonic frequency even when the second harmonic frequency is within an operating frequency band of a fundamental frequency of the amplifier circuit. In one embodiment, the amplifier circuit includes a bypass circuit which selectively couples balun ports to ground such that in response to a first control signal, the amplifier circuit operates in an amplifying mode and in response to a second control signal, the amplifier circuit operates in a bypass mode.

Abstract: A vehicle operation assembly comprising: stairs including a step; and a vehicle operation system positioned behind the stairs such that the step of the stairs is exposed for use in front of the vehicle operation system, the stairs being adapted to permit access to the vehicle operation system. The vehicle operation system may include a sleeper cab heater, a hydraulic system, a diesel generator, or a fuel supplement system such as a hydrogen generating system.

Abstract: The invention provides compositions and methods for more thoroughly cleaning internal combustion engines, fuel systems and emission systems and that operate with reduced toxic emissions. The invention provides an apparatus that contains at least one vessel for receiving a cleaning fluid and an electrode in a cleaning fluid flow path configured to apply a charge to a cleaning fluid. The cleaning fluids are unique fuel derived products which do not contain detergents. The apparatus is unique in that it can provide any of several cleaning processes including a pre-combustion cleaning process, a post-combustion cleaning process or a combined pre-combustion and post-combustion cleaning process. The method is particularly effective at cleaning oxygen sensors in exhaust systems.

Abstract: A novel filtration media employing polymeric absorbents comprising a material selected from the group consisting of styrene, pentadiene, cyclopentadiene, butylene, ethylene, isoprene, butadiene, propylene and mixtures thereof; and a filtration enabler intimately mixed with the polymeric absorbent. Upon contact with a hydrocarbon containing liquid, the liquid partially dissolves the polymeric absorbent forming a partial filtration barrier prior to the filtration media substantially absorbing the hydrocarbons, and allowing hydrocarbon-free liquid to flow through the filtration media. In situations of a leak or spill wherein an excess of hydrocarbons are present, the filtration media forms a plug to seal and prevent further discharge of the hydrocarbons. The filtration media may be placed inside a portable container for insertion into an existing drain such that hydrocarbon containing liquid is filtered through the device allowing hydrocarbon-free liquid to flow from the device.

Abstract: A novel filtration media employing polymeric absorbents comprising a material selected from the group consisting of styrene, pentadiene, cyclopentadiene, butylene, ethylene, isoprene, butadiene, propylene and mixtures thereof; and a filtration enabler intimately mixed with the polymeric absorbent. Preferably, the filtration enabler comprises clay, ground glass, talc, mica, recycled rubber, sand, gravel, vermiculite, recycled plastic chips, an inert, non-absorbent material, or mixtures thereof. Preferably, the polymeric absorbent may be further compounded to incorporate about 10 to 50% recycled or waste plastic scrap, scrap polyolefins, inorganic fillers, or other inexpensive, relatively inert solids. Other compounding materials may include clay, talc, mica, ground glass, silica, and mixtures thereof.

Abstract: A novel filtration media employing polymeric absorbents comprising a material selected from the group consisting of styrene, pentadiene, cyclopentadiene, butylene, ethylene, isoprene, butadiene, propylene and mixtures thereof; and a filtration enabler intimately mixed with the polymeric absorbent. Preferably, the filtration enabler comprises clay, ground glass, talc, mica, recycled rubber, sand, gravel, vermiculite, recycled plastic chips, an inert, non-absorbent material, or mixtures thereof. Preferably, the polymeric absorbent may be further compounded to incorporate about 10 to 50% recycled or waste plastic scrap, scrap polyolefins, inorganic fillers, or other inexpensive, relatively inert solids. Other compounding materials may include clay, talc, mica, ground glass, silica, and mixtures thereof.