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.

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.

Abstract: A tuned switching power amplifier having a switch for receiving an AC input signal. The switch controls the application of DC power to a load through a load network. The load network develops a parallel inductance and a parallel capacitance across the switch that minimizes power losses associated with the switch by creating a transient response across the switch that insures that, when the switch transitions from on to off, the voltage across the switch remains low until the current trough the switch reaches zero, and that, when the switch transitions from off to on, the voltage across the switch is zero and has a substantially zero time derivative prior to when the switch transitions from off to on. The parallel inductance is developed by a transmission line of a determined electrical length.