Fast switched pulsed radio frequency amplifiers
AssigneeWeather Detection Systems, Inc.
InventorRick Smeltzer
Life of this patent
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Abstract
A switching system is connected to the power amplifier of an RF system. The switching system can switch the DC supply voltage to the power amplifier while handling the high DC current and the nanosecond switching speed requirements that are mandatory for most RF systems. The embodiments can rapidly control DC voltages but not interfere with the optimized operation of the RF transistor. The embodiments provide a desired sharp turn-on leading edge for an RF pulse while eliminating the extremely long and undesirable ramp down that typically occurs beyond the desired RF pulse period.
Claims20
A radio frequency (RF) circuit, comprising:
- a voltage source that supplies gain voltage;
- a power amplifier;
- and
- a switch electrically coupled to the voltage source, ground, and the power amplifier, wherein the switch selectively applies the gain voltage to the power amplifier and/or selectively applies ground to the power amplifier.
A method for controlling a radio frequency (RF) circuit, comprising:
- receiving a trigger signal;
- based on the trigger signal, switching an on state GaNFET, electrically coupled to a RF power metal oxide fiend effect transistor (MOSFET) amplifier, to connect a drain of the RF power MOSFET power amplifier to a DC voltage source;
- amplifying an RF signal with the RF power MOSFET amplifier while the on state GaNFET is switched;
- ending an RF envelope;
- based on ending the RF envelop:
- switching again the on state GaNFET;
- switching an off state GaNFET, also electrically coupled to the RF power MOSFET amplifier, to drive the drain of the RF power MOSFET amplifier substantially to ground;
- and
- discontinuing amplification of the RF signal with the RF power MOSFET amplifier.
A RF circuit, comprising:
- a power amplification circuit comprising an RF power metal oxide fiend effect transistor (MOSFET) comprising at least a gate, a source, and a drain, wherein the power amplification circuit amplifies a received RF signal;
- a DC voltage source providing a gain voltage;
- a ground;
- a switching circuit electrically coupled to the drain of the RF power MOSFET, the switching circuit comprising:
- a Schmitt trigger to receive a trigger source and to convert the trigger source into a digital trigger signal;
- an IC gate electrically coupled to the Schmitt trigger to receive the digital trigger signal and supply a gate trigger signal;
- a gate driver electrically coupled to the IC gate to receive the gate trigger signal and to send a gate signal to a Hi gate signal and/or a Low gate signal;
- a first GaNFET electrically coupled to the gate driver, wherein, based on receiving the Hi gate signal, electrically coupling the DC voltage source to the drain of the RF power MOSFET to amplify the received RF signal, wherein the first GaNFET switches the drain to the gain voltage in less than 100 nanoseconds;
- and
- a second GaNFET electrically coupled to the gate driver and electrically coupled to the first GaNFET in an H-bridge configuration, wherein, based on receiving the Low gate signal, electrically coupling the ground to the drain of the RF power MOSFET to ceasing the amplification of the received RF signal, wherein the second GaNFET drive the drain to the ground in less than 10 nanoseconds.
Dependencies are inferred from the claim text.