Oscillator frequency offsets
First Claim
1. A method of producing an output signal having an output frequency related to a local oscillator frequency, the method comprising:
- a) feeding an input signal having an input frequency into a double quadrature mixer circuit;
b) feeding a local oscillator signal into the circuit, the local oscillator signal having the local oscillator frequency; and
c) receiving the output signal from an output of the circuit, the output signal having an output frequency substantially equal to a value chosen from a group consisting of;
a difference of the oscillator frequency subtracted from the input frequency; and
the sum of the local oscillator frequency and the input frequency.
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Accused Products
Abstract
Methods and devices relating to radio applications. An input signal with an input frequency is fed into a double quadrature mixer circuit along with a local oscillator signal with a local oscillator frequency. These two signals are multiplied by the mixer circuit and produces an output signal with a frequency substantially equal to either a sum of the local oscillator frequency and the input frequency or a difference of the local oscillator frequency and the input frequency. By using the quadrature mixer, the output signal consists mainly of only one sideband of the multiplication process. The carrier is mainly suppressed along with the other sideband. The output signal is particularly useful as a small frequency offset for a synthesized signal.
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Citations
14 Claims
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1. A method of producing an output signal having an output frequency related to a local oscillator frequency, the method comprising:
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a) feeding an input signal having an input frequency into a double quadrature mixer circuit;
b) feeding a local oscillator signal into the circuit, the local oscillator signal having the local oscillator frequency; and
c) receiving the output signal from an output of the circuit, the output signal having an output frequency substantially equal to a value chosen from a group consisting of;
a difference of the oscillator frequency subtracted from the input frequency; and
the sum of the local oscillator frequency and the input frequency. - View Dependent Claims (8, 10, 11, 12)
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2. A method of generating frequency offsets for a frequency synthesizer, the method comprising:
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a) feeding an input signal with an input frequency to an input of said frequency synthesizer;
b) generating a local oscillator signal having a local oscillator frequency;
c) feeding said local oscillator signal to a local oscillator input of said frequency synthesizer such that said local oscillator frequency is multiplied with said input frequency; and
d) producing an output signal at an output of said frequency synthesizer, said output signal having an output frequency substantially equal to a value chosen from a group consisting of;
a difference of the oscillator frequency subtracted from the input frequency; and
the sum of the local oscillator frequency and the input frequency wherein the frequency synthesizer is a double quadrature mixer. - View Dependent Claims (3, 7)
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4. A circuit for use in heterodyne applications, the circuit comprising:
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a double quadrature mixer block having an input, a local oscillator input, and at least one output;
a local oscillator for generating a local oscillator signal having a local oscillator frequency;
first circuit means for sending an input signal to the mixer block said first circuit means being coupled to said input of said mixer block and said input signal having an input frequency second circuit means for sending a local oscillator signal to said local oscillator input of said mixer block, said second circuit means being coupled to said local oscillator input;
output circuit means for receiving at least one output signal of said mixer block, said output circuit means being coupled to said at least one output of said mixer block, wherein said at least one output signal has an output frequency substantially equal to a value chosen from a group consisting of;
a difference of the oscillator frequency subtracted from the input frequency; and
the sum of the local oscillator frequency and the input frequency. - View Dependent Claims (5, 6, 9, 13, 14)
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Specification