Adjustable radio frequency power amplifier and transmitter
First Claim
1. A radio frequency power amplifier and transmitter for driving an antenna to radiate radio frequency energy, the radio frequency power amplifier and transmitter comprising:
- a first plurality of buffers coupled together in parallel, the first plurality of buffers receiving a waveform signal as input and providing a driving signal to the antenna;
a first inverter receiving the waveform signal as an input, the first inverter generating an out-of-phase waveform signal;
a second plurality of buffers coupled together in parallel, the second plurality of buffers receiving the out-of-phase waveform signal from the first inverter as input and providing an out-of-phase driving signal to the antenna; and
wherein the first plurality of buffers and the second plurality of buffers are pushing or pulling responsive to the waveform signal and the out-of-phase waveform signal such that radio frequency energy is radiated by the antenna.
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Accused Products
Abstract
A modulator (104) varies the duty cycle of a waveform to amplitude modulate information for transmission. A push-pull amplifier (106) in accordance with the invention, preferably constructed of CMOS devices, receives the waveform with a varying duty cycle in order to drive an antenna (108) such that a wireless transceiver can become excited by the oscillating waveform and receive the amplitude modulated signal and demodulate it to obtain the transmitted information. The power generated by the push-pull power amplifier (106) is simply increased or decreased by varying the voltage of the power supplied to the power amplifier or by varying the number of devices driving the antenna (108) in parallel.
85 Citations
16 Claims
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1. A radio frequency power amplifier and transmitter for driving an antenna to radiate radio frequency energy, the radio frequency power amplifier and transmitter comprising:
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a first plurality of buffers coupled together in parallel, the first plurality of buffers receiving a waveform signal as input and providing a driving signal to the antenna; a first inverter receiving the waveform signal as an input, the first inverter generating an out-of-phase waveform signal; a second plurality of buffers coupled together in parallel, the second plurality of buffers receiving the out-of-phase waveform signal from the first inverter as input and providing an out-of-phase driving signal to the antenna; and wherein the first plurality of buffers and the second plurality of buffers are pushing or pulling responsive to the waveform signal and the out-of-phase waveform signal such that radio frequency energy is radiated by the antenna. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A radio frequency exciter for exciting and transmitting information to a wireless transceiver, the radio frequency exciter comprising:
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an antenna having a first connection at one end and a second connection at an opposite end; a modulator that generates a carrier signal and varies a duty cycle of the carrier signal in response to the information; a power amplifier coupled to the modulator and the first and second connection of the antenna, the power amplifier receiving and amplifying the carrier signal responsive to the duty cycle, the power amplifier comprising; a first plurality of buffers coupled together in parallel, the first plurality of buffers receiving the carrier signal responsive to duty cycle as input and providing a driving signal to the first connection to the antenna; a first inverter that receives the carrier signal as an input, the first inverter generating an out-of-phase waveform signal; a second plurality of buffers coupled together in parallel, the second plurality of buffers receiving as input the out-of-phase waveform signal from the first inverter and providing an out-of-phase driving signal to the second connection to the antenna; and wherein the first plurality of buffers and the second plurality of buffers are pushing or pulling responsive to the carrier signal and the out-of-phase waveform signal such that radio frequency energy is radiated by the antenna. - View Dependent Claims (11, 12, 13)
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14. A method for amplifying and modulating an oscillating waveform of a carrier signal in order to transmit information to a wireless transceiver, the method comprising the steps of:
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(a) generating the oscillating waveform with a duty cycle of approximately fifty percent; (b) filtering out undesirable harmonics from the oscillating waveform; (c) varying the duty cycle of the oscillating waveform responsive to information to generate a variable duty cycle oscillating waveform; (d) amplifying the variable duty cycle oscillating waveform with a CMOS power amplifier to generate an amplified variable duty cycle oscillating waveform; and (e) driving an antenna with the amplified variable duty cycle oscillating waveform to transmit information to the wireless transceiver. - View Dependent Claims (15, 16)
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Specification