Simplified high frequency tuner and tuning method
AssigneeUniversity of Washington
InventorEdwin A. Suominen
Life of this patent
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Abstract
A disclosed method tunes a signal from a channelized spectrum having a predetermined channel spacing. A signal of interest having a predetermined maximum bandwidth is mixed with a local oscillator signal, which has a frequency that is an integer multiple of the channel spacing or one-half of a channel spacing displaced from an integer multiple of the channel spacing. The local oscillator signal is selected to frequency translate the signal of interest to within a near-baseband passband whose lower edge is spaced from DC by at least about the maximum bandwidth of the signal of interest. Problems associated with 1/f noise, DC offsets, and self-mixing products are avoided or substantially diminished. Other methods and systems are also disclosed.
Claims67
A tuning method comprising:
- (a) receiving a channel of interest from a channelized spectrum having a predetermined channel spacing;
- (b) frequency translating the channel of interest, by mixing with a local oscillator signal having a frequency that is one of a set of local oscillator frequencies, to within a near-baseband passband that has a maximum bandwidth that is about the channel spacing;
- and
- (c) dynamically varying the passband bandwidth.
A tuning method comprising:
- (a) receiving a channel of interest from a channelized spectrum having a predetermined channel spacing;
- (b) frequency translating the channel of interest, by mixing it with a local oscillator signal having a frequency that is one of a set of local oscillator frequencies, to within a passband that is near baseband and the lower edge of which is spaced from DC by at least about the channel spacing and that has a bandwidth that is about the channel spacing plus a fine tuning adjustment;
- and
- (c) fine tuning the channel of interest by passing a selected range of bandpass frequencies.
A tuning method comprising:
- (a) receiving a channel of interest from a channelized spectrum having predetermined channel spacing;
- (b) frequency translating the channel of interest by mixing it with a local oscillator signal having a frequency that is one of a set of local oscillator frequencies, to within a near-baseband passband that has a bandwidth that is about the channel spacing plus a fine tuning adjustment;
- and
- (c) fine tuning the channel of interest by digitally controlled variable bandpass filtering to pass a selected range of passband frequencies.
An apparatus for tuning, from a channelized spectrum having a predetermined channel spacing, a channel of interest, the apparatus comprising:
- (a) a local oscillator configured to generate a local oscillator signal;
- (b) a mixer responsive to the local oscillator signal and the channel of interest, wherein the mixer frequency-translates the channel of interest;
- (c) a filter configured to define a near-baseband passband;
- and
- (d) a variable bandpass filter responsive to control inputs and configured to fine-tune the channel of interest by passing a range of frequencies within the near-baseband passband;
- (e) wherein the frequency-translated channel of interest falls within the near-baseband passband.
A tuning method comprising:
- (a) receiving a channel of interest from a channelized spectrum having a predetermined channel spacing;
- (b) frequency translating the channel of interest by mixing with a first local oscillator signal having a frequency that is one of a set of local oscillator frequencies, to within a near-baseband passband that has a bandwidth that is about the channel spacing;
- and
- (c) further translating the frequency-translated channel of interest by mixing the frequency-translated channel of interest with a second local oscillator signal.
Apparatus for tuning, from a channelized spectrum having a predetermined channel spacing, a channel of interest, the apparatus comprising:
- (a) a first local oscillator configured to generate a first local oscillator signal;
- (b) a filter configured to define a near-baseband passband;
- (c) a first mixer, responsive to the first local oscillator signal and the channel of interest, that frequency-translates the channel of interest to within the near-baseband passband;
- (d) a variable bandpass filter responsive to control inputs and configured to vary the width of the near-baseband passband;
- and
- (e) a baseband translator configured to translate the frequency-translated channel of interest to baseband.
A tuning method comprising:
- (a) mixing a signal of interest from a channelized spectrum having a predetermined channel spacing with a first local oscillator signal that is coarse-tunable across the channelized spectrum with a step size that is an integer multiple of the channel spacing, having a first frequency that is selected to frequency translate the channel of interest to within a passband defined with reference to a lower frequency Fl and an upper frequency F2, wherein F1=F2−F1 and F1 is at least about the maximum bandwidth of the signal of interest;
- and
- (b) mixing the signal of interest with a second local oscillator signal having the first frequency and being approximately in quadrature with the first local oscillator signal;
- (c) wherein the signal of interest lies within one of an upper high frequency spectrum of interest and a lower high frequency spectrum of interest and the method further comprises providing spectrum coverage within one of the high frequency spectra of interest and not the other.
Apparatus for tuning, from a channelized spectrum having a predetermined channel spacing, a signal of interest, the apparatus comprising:
- (a) a local oscillator configured to generate an approximately quadrature local oscillator signal that is coarse-tunable across the channelized spectrum with a step size that is an integer multiple of the channel spacing;
- and
- (b) a quadrature mixer responsive to the local oscillator signal and the signal of interest, wherein the mixer frequency translates the signal of interest to within a passband defined with reference to a lower frequency Fl and an upper frequency F2, wherein F1=F2−F1 and F1 is at least about the maximum bandwidth of the signal of interest;
- (c) wherein the signal of interest lies within one of an upper high frequency spectrum of interest and a lower high frequency spectrum of interest, and the apparatus provides spectrum coverage within one of the high frequency spectra of interest and not the other.
Apparatus for tuning, from a channelized spectrum having a predetermined channel spacing, a signal of interest, the apparatus comprising:
- (a) a local oscillator configured to generate approximately quadrature local oscillator signals;
- and
- (b) mixers responsive to the local oscillator signals and the signal of interest, wherein the mixers frequency translate the signal of interest to within a near-baseband passband that is spaced from DC by about the passband width;
- (c) wherein the local oscillator signals have a frequency that dynamically tracks frequency movement of the signal of interest;
- (d) the signal of interest lies within one of an upper high frequency spectrum of interest and a lower high frequency spectrum of interest and spectrum coverage is provided within one of the high frequency spectra of interest and not the other.
Dependencies are inferred from the claim text.