Abstract: A high efficiency, multiple power output power amplifier uses a pair of amplifiers having similar characteristics coupled to a pair of radio frequency RF couplers. When both amplifiers are operating, the power output is the sum of the outputs of the two amplifiers. When lower power operation is desired, one of the amplifiers is turned off and a high impedance is presented to the isolated port of the output RF coupler, thereby ensuring that all of the power output of the remaining power amplifier is available for output.

Abstract: The bias control selectively provides for bias of a power amplifier based upon a bandgap voltage generated by the bias control, or by a bias voltage external to the bias control. A controller controls the selection of either the bandgap voltage or external bias voltage. The bias control is fabricated in a first semiconductor material capable of operating at low voltage supply levels, such as complementary metal oxide semiconductor (CMOS) material and may be fabricated on an integrated circuit common with a power amplifier.

Abstract: A valve assembly comprises a valve stem, an annular bonnet configured to receive the valve stem, a valve disk coupled to one end of the valve stem, a seal, and an insert. The seal is disposed adjacent the valve disk and has a top surface and a bottom surface. The top surface includes a first pair of sealing ridges extending upwardly therefrom and the bottom surface includes a second pair of sealing ridges extending downwardly therefrom. The insert includes a recess configured to receive the seal that performs a sealing function and a biasing function. The valve assembly can easily be configured to open in either a clockwise or counterclockwise direction without resort to adapters or other additional pieces by rotating the bonnet/valve stem sub-assembly 90° relative to the insert.