Saw stabilized FSK oscillator circuit
First Claim
1. A digitally-controlled SAW stabilized FSK oscillator circuit comprising:
- an oscillator;
a single-port SAW resonator having a predetermined circuit resonant frequency and being coupled to the oscillator for establishing a first oscillator output frequency, FSAW ; and
a transistor having an ON and an OFF state, only said transistor being coupled in series with the single-port SAW resonator for establishing the first frequency, FSAW, when the transistor is in the ON state and causing said oscillator to shift its output frequency from the first frequency, FSAW, to a second frequency, F2, when said transistor is in its OFF state.
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Accused Products
Abstract
A digitally-controlled SAW stabilized FSK oscillator circuit having an oscillator and a single-port SAW resonator with a predetermined circuit resonant frequency and being coupled to the oscillator for establishing a first oscillator output frequency, FSAW. A bipolar transistor has at least one predetermined shunt capacitance value, C, that is placed in electrical series with the single-port SAW resonator when the transistor is in the OFF state and a closed switch that replaces the capacitance when the transistor is in the ON state to cause the first frequency, FSAW, to be generated by the oscillator when the transistor is ON and to cause a second frequency, F2, to be generated by the oscillator when the transistor is in the OFF state.
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Citations
12 Claims
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1. A digitally-controlled SAW stabilized FSK oscillator circuit comprising:
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an oscillator; a single-port SAW resonator having a predetermined circuit resonant frequency and being coupled to the oscillator for establishing a first oscillator output frequency, FSAW ; and a transistor having an ON and an OFF state, only said transistor being coupled in series with the single-port SAW resonator for establishing the first frequency, FSAW, when the transistor is in the ON state and causing said oscillator to shift its output frequency from the first frequency, FSAW, to a second frequency, F2, when said transistor is in its OFF state. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A SAW stabilized FSK oscillator for use in an FSK transmitter comprising:
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an oscillator; a single-port SAW resonator having a predetermined circuit resonant frequency and being coupled to the oscillator for establishing a first oscillator output frequency, FSAW ; a bipolar transistor in electrical series with said single-port SAW resonator, said bipolar transistor having at least one inherent internal shunt capacitance value, C; said transistor having a first conducting state forming a closed switch to cause said first frequency, FSAW, to be generated by said oscillator and a second non-conducting state in which said at least one inherent internal shunt capacitance replaces said closed switch and is coupled in electrical series with said SAW resonator to cause said second frequency, F2, to be generated by said oscillator; a digital data source being coupled to said bipolar transistor for causing said bipolar transistor to change between said first and second states; and an impedance-matching circuit coupled to said oscillator output for providing an FSK output to be transmitted at RF frequencies. - View Dependent Claims (11, 12)
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Specification