R. F. power amplifier
AssigneeU.S. Philips Corporation
InventorJeremy K. A. Everard
Life of this patent
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Abstract
An r.f. power amplifier, typically a high efficiency, class E amplifier in which a reactive load circuit (18) is connected to a semiconductor switching device (10), the load circuit being designed to have the required input load angle and loaded Q so that the voltage across the device (10) goes to zero with zero slope before it switches on and passes current, is provided with a step recovery diode (32) connected to the device (10) to limit the voltage swing across the device (10) with no significant loss of efficiency. This allows the voltage-handling capability required of the device to be reduced or the amplifier output power to be increased by increasing the supply voltage.
Claims5
An r.f. power amplifier comprising a switching device having a pair of main electrodes, and a load network capable of adjusting the relative phase of the voltages across and the currents flowing between said main electrodes, wherein the amplifier comprises semiconductor means for limiting the peak voltage swing across said main electrodes by storing charge in response to charging of capacitance in parallel with said main electrodes attempting to drive the voltage across said main electrodes to above a predetermined value and releasing the stored charge in response to discharging of said capacitance subsequently attempting to reduce said voltage once again.
An improved r.f. power amplifier of the type having a switching device and a load network capable of adjusting the relative phase of the voltages across and currents through the switching device, wherein the amplifier comprises semiconductor means for limiting the peak voltage swing across the switching device by storing charge during substantially the time period that the voltage is being limited and subsequently releasing the stored charge, and wherein the semiconductor means comprises a step recovery diode.
An improved r.f. power amplifier of the type having a switching device and a load network capable of adjusting the relative phase of the voltages across and currents through the switching device, wherein the amplifier comprises semiconductor means for limiting the peak voltage swing across the switching device by storing charge during substantially the time period that the voltage is being limited and subsequently releasing the stored charge, and wherein the semiconductor means comprises a Schottky diode coupled to a bias supply comprising a load network including a capacitor and inductor coupled in parallel.
Dependencies are inferred from the claim text.