Harmonic boost technique for direct conversion receiver
OwnerChing-Lang Lininventor
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Abstract
The present invention describes an Improved Harmonic Boosting Technique (IHBT) for achieving zero DC-offset in a direct conversion receiver (DCR). The technique may be applied to devices such as down converter, combiner, synthesizer, and voltage control oscillator. The present invention utilizes a voltage control oscillator (VCO) to generate lower even-order frequencies based on the receiver's carrier frequency (RF). A synthesizer, having a digital synthesizing circuit or a frequency multiplier circuit, produces odd order harmonic frequencies from the output of the VCO. A combiner combines odd order harmonic frequencies from the synthesizer to create a local oscillator (LO) signal. A down converter mixes an input signal with the LO output from the combiner.
Claims22
A harmonic boosting technique that produces zero DC offsets and reduces LO frequency and power, comprising the steps of:
- generating an output with a voltage controlled oscillator (VCO), wherein the VCO generates output LOe1, and wherein the outputs are received by a digital synthesizer or frequency multiplier device;
- producing a set of n odd harmonic frequencies, LOe1, LOe3 . . . LOeoddn of LOe1 with said digital synthesizer or frequency multiplier device as inputs for a combiner or adder circuit;
- combining in said combiner or adder circuit these n odd frequencies together to become LOr, an input to a down converter;
- and
- mixing a received RF signal with the LOr input to produce a zero intermediate frequency signal in said down converter.
An apparatus to harmonically boost signals that produces zero DC offsets and reduces LO frequency and power, comprising the steps of:
- a voltage controlled oscillator (VCO), wherein the VCO generates output LOe1;
- a digital synthesizer or frequency multiplier device that receives said output LOe1 and produces a set of n odd harmonic frequencies, LOe1, LOe3 . . . LOeoddn of LOe1;
- a combiner or adder circuit that mixes said n odd frequencies together to become LOr;
- a down converter which mixes a received RF signal with LOr to produce a zero intermediate frequency signal.
A harmonic boosting technique that produces zero DC offsets and reduces LO frequency and power, comprising the steps of:
- generating an output with a voltage controlled oscillator (VCO), wherein the VCO generates output LOe1, and wherein the outputs are received by a digital synthesizer or frequency multiplier device;
- producing a set of n odd harmonic frequencies, LOe1, LOe3 . . . LOeoddn of LOe1 with said digital synthesizer or frequency multiplier device as inputs for a combiner or adder circuit;
- combining in said combiner or adder circuit these n odd frequencies together to become LOr, an input to an up converter;
- and
- mixing a transmitted RF signal with the LOr input to produce a zero intermediate frequency signal in said up converter.
An apparatus to harmonically boost signals that produces zero DC offsets and reduces LO frequency and power, comprising the steps of:
- a voltage controlled oscillator (VCO), wherein the VCO generates output LOe1;
- a digital synthesizer or frequency multiplier device that receives said output LOe1 and produces a set of n odd harmonic frequencies, LOe1, LOe3 . . . LOeoddn of LOe1;
- a combiner or adder circuit that mixes said n odd frequencies together to become LOr;
- a up converter which mixes a transmitted RF signal with LOr to produce a zero intermediate frequency signal.
Dependencies are inferred from the claim text.