System and method for modulating a frequency signal
First Claim
1. A radio frequency transmitter circuit comprising:
- a user input switch for producing an input signal;
an oscillator for producing a frequency signal having a first frequency;
an antenna connected to said oscillator for broadcasting said frequency signal;
a coupling signal disposed a predetermined distance from said antenna; and
a microprocessor for enabling said oscillator and activating said coupling circuit in response to said input signal;
said coupling circuit arranged to produce a reflected impedance when activated to alter an inductance of said antenna, thereby shifting said frequency signal to a second frequency upon activation of said coupling circuit.
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Accused Products
Abstract
A radio frequency transmitter circuit including a user input switch for producing an input signal, an oscillator for producing a frequency signal having a first frequency, an antenna connected to the oscillator for broadcasting the frequency signal, a coupling circuit disposed a predetermined distance from the antenna, and a microprocessor for enabling the oscillator and activating the coupling circuit in response to the input signal. When the coupling circuit is activated, a reflected impedance, derived from a change in inductance, is reflected from the coupling circuit upon the antenna thereby shifting the frequency signal to a second frequency. Sequentially activating and deactivating the coupling circuit modulates the frequency signal.
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Citations
7 Claims
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1. A radio frequency transmitter circuit comprising:
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a user input switch for producing an input signal;
an oscillator for producing a frequency signal having a first frequency;
an antenna connected to said oscillator for broadcasting said frequency signal;
a coupling signal disposed a predetermined distance from said antenna; and
a microprocessor for enabling said oscillator and activating said coupling circuit in response to said input signal;
said coupling circuit arranged to produce a reflected impedance when activated to alter an inductance of said antenna, thereby shifting said frequency signal to a second frequency upon activation of said coupling circuit. - View Dependent Claims (2, 3, 4)
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5. A method of modulating a signal comprising:
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a) generating a signal having a first frequency from an oscillator circuit; and
b) producing a reflected impedance to selectively alter an inductance of an antenna in the oscillator circuit to shift the signal to a second frequency. - View Dependent Claims (6, 7)
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Specification