Abstract: Apparatus, methods and articles of manufacture are shown for modifying electromagnetic waves. Through using various wave characteristics such as amplitude to regulate a current source, a current is output that may be used in any number of ways, such as driving an antenna or other load.

Abstract: A power amplifier having a first stage amplifier and a second stage amplifier, each stage of the power amplifier being configured in one of at least two power states based on a desired power output. When the first and second stages are configured in a first state, the power amplifier delivers efficient amplification in a first output power range and, when the first and second stages are configured in a second state, the power amplifier delivers efficient amplification in a second output power range. By configuring each stage in one of at least two states, a high level of power efficiency can be achieved for a broad range of power levels.