1. Field of the Invention
The present invention relates to circuitry, and in particular relates to a power combiner and a power distributor in a signal processing apparatus.
2. Description of the Related Art
Power amplifiers (PAs) are electronic devices that amplify power of RF signals by converting DC power into RF power in various RF transceiving devices and systems. Many amplifiers used in a transceiver system tend to occupy a large chip or board area, require high DC power, and need to dissipate heat generated during operation. When required power output level for the amplifier exceeds the capabilities of a signal power amplifier cell, multiple amplifier cells can be combined to produce the required output. Power combiners are closely related to wideband transformers in design and construction. A power distributor is a lower powered version of a power combiner and is used in reverse. The power distributor divides a source signal into multiple equal-amplitude driving signals to drive multiple PAs in the transceiving system or feed multiple phase shifters in a phased array system. Increased efficiency and linearity of the power combiners/distributors are demanded in wireless communications and other RF applications.