Abstract: An RF power amplifier including a splitter, two branch circuits, and a combiner. The splitter has an input line receiving an RF signal, a first output line carrying a first output signal derived from the RF signal, and a second output line carrying a second output signal derived from the RF signal. A first branch circuit receives the first output signal and generates therefrom a first derived signal. A second branch circuit receives the second output signal and generates therefrom a second derived signal therefrom. The first branch circuit includes a first power amplifier and a phase shifting element. The second branch circuit includes a second power amplifier. The combiner, which has a first input receiving the first derived signal and a second input receiving the second derived signal, combines the first and second derived signals to produce a power output signal therefrom.

Abstract: An RF plasma power monitor that monitor voltage, current and DC bias adjacent the plasma load and processes the sensed data in a digital data processor to provide true power at the load. Provision is also made for the control of an RF power source to maintain power at the load at a preset level irrespective on impedance fluctuations and reflections.

Abstract: In a processing system comprising a plurality of modules, the presence of one or more modules is sensed at a control unit through the use of an analog encoder and an A/D converter. The modules terminate selected resistors in a binary resistance network in the analog encoder to produce a unique signal via the A/D converter for each combination of modules in the system. The encoder requires a minimal number of signal lines and no multiplexing of signals.