Simplified high frequency tuner and tuning method

• US 9,172,416 B2
• Filed: 11/07/2014
• Issued: 10/27/2015
• Est. Priority Date: 09/13/1996
• Status: Expired due to Fees

• Current Assignee: University of Washington
• Original Assignee: University of Washington
• Inventors: Suominen, Edwin A.
• Primary Examiner(s): Jackson, Blane J
• Application Number:
  US14/536,246
• Publication Number:
  US 20150065074A1
• Time in Patent Office: 354 Days
• Field of Search: 455/255, 455/256, 455/257, 455/258, 455/260, 455/266, 455/296, 455/302, 455/323
• US Class Current: 1/1
• CPC Class Codes: H03D 3/007 by converting the oscillations into two quadrature related signals H03D3/245 takes precedence
• CPC Class Codes: H03D 3/009 Compensating quadrature phase or amplitude imbalances
• CPC Class Codes: H03D 7/165 at least two frequency changers being located in different paths, e.g. in two paths with carriers in quadrature combined with amplitude demodulation H03D1/2245, combined with angle demodulation H03D3/007; N-path filters H03H19/002
• CPC Class Codes: H04B 1/06 Receivers
• CPC Class Codes: H04B 1/10 Means associated with receiver for limiting or suppressing noise or interference
• CPC Class Codes: H04B 1/16 Circuits
• CPC Class Codes: H04B 1/26 for superheterodyne receivers multiple frequency-changing H03D7/16
• CPC Class Codes: H04B 1/30 for homodyne or synchrodyne receivers demodulator circuits H03D1/22
• CPC Class Codes: H04L 25/067 providing soft decisions, i.e. decisions together with an estimate of reliability H04L25/068 and H04L25/069 take precedence; sequence estimation techniques H04L25/03178

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.

Claims

1. A tuner comprising:

a local oscillator that provides a local oscillator signal having a frequency selected from a plurality of local oscillator frequencies and

a continuous-time mixer that mixes an incoming signal with the local oscillator signal so as to translate a lower high frequency spectrum of interest and an upper high frequency spectrum of interest, each spectrum carrying at least a different channel of information from the other spectra, to within a passband,

improved wherein the local oscillator frequencies of the plurality are spaced such that any high frequency spectral pair can be tuned from only one local oscillator frequency of the plurality and such that there is substantially no redundant spectral coverage between;

an upper and lower high frequency spectrum of interest desired to be recovered frequency-translated to the passband when the local oscillator signal has any first local oscillator frequency of the plurality

and an upper and lower high frequency spectrum of interest desired to be recovered frequency-translated to the passband when the local oscillator signal has any local oscillator frequency of the plurality other than the first local oscillator frequency of the plurality,

wherein the passband comprises a range of frequencies passed by a low pass filter and excluding DC and the −

3 dB frequency responses of the low pass filter is wider than the near-baseband passband.

2. The tuner of claim 1 wherein the continuous-time mixer comprises continuous-time quadrature mixers that provides I and Q signals in approximate quadrature relationship.

3. The tuner of claim 2 further comprising a digital signal processing device responsive to the I and Q signals to substantially reject either the translated lower high frequency spectrum of interest or the translated upper high frequency spectrum of interest.

4. The tuner of claim 3 wherein the digital signal processing device is structured and arranged to perform complex multiplication on the non-rejected translated spectrum of interest to effect frequency translation of a signal of interest from said spectrum of interest to baseband.

5. The tuner of claim 4 wherein the digital signal processing device is structured and arranged so as to be able to correct errors between the I and Q signals.

6. The tuner of claim 1 further comprising a digital signal processing portion including first and second analog-to-digital converters in the form of delta-sigma modulators each of which samples a signal mixed by the mixer, and wherein the delta-sigma modulators are each followed by a decimating filter.

7. A tuner comprising:

a local oscillator that provides a local oscillator signal having a frequency selected from a plurality of local oscillator frequencies and

a continuous-time mixer that mixes an incoming signal with the local oscillator signal so as to translate a lower high frequency spectrum of interest and an upper high frequency spectrum of interest to within a passband,

improved wherein the local oscillator frequencies of the plurality are spaced such that any high frequency spectral pair can be tuned from only one local oscillator frequency of the plurality and such that there is substantially no redundant spectral coverage between;

an upper and lower high frequency spectrum of interest translated to the passband when the local oscillator signal has any first local oscillator frequency of the plurality;

and an upper and lower high frequency spectrum of interest translated to the passband when the local oscillator signal has any local oscillator frequency of the plurality other than the first local oscillator frequency of the plurality,

wherein the passband comprises a range of frequencies passed by a low pass filter and excluding DC and the information contained in the upper high frequency spectrum differs from the information contained in the corresponding lower high frequency spectrum of interest.

8. The tuner of claim 7 wherein the continuous-time mixer comprises continuous-time quadrature mixers that provides I and Q signals in approximate quadrature relationship.

9. The tuner of claim 8 further comprising a digital signal processing device responsive to the I and Q signals to substantially reject either the translated lower high frequency spectrum of interest or the translated upper high frequency spectrum of interest.

10. The tuner of claim 9 wherein the digital signal processing device is structured and arranged to perform complex multiplication on the non-rejected translated spectrum of interest to effect frequency translation of a signal of interest from said spectrum of interest to baseband.

11. The tuner of claim 10 wherein the digital signal processing device is structured and arranged so as to be able to correct errors between the I and Q signals.

12. The tuner of claim 7 further comprising a digital signal processing portion including first and second analog-to-digital converters in the form of delta-sigma modulators each of which samples a signal mixed by the mixer, and wherein the delta-sigma modulators are each followed by a decimating filter.

13. A tuner comprising:

a local oscillator that provides a local oscillator signal having a frequency selected from a plurality of local oscillator frequencies and

a continuous-time mixer that mixes an incoming signal with the local oscillator signal so as to translate a lower high frequency spectrum of interest and an upper high frequency spectrum of interest to within a passband,

improved wherein the local oscillator frequencies of the plurality are spaced such that any high frequency spectral pair can be tuned from only one local oscillator frequency of the plurality and such that there is substantially no redundant spectral coverage between;

an upper and lower high frequency spectrum of interest translated to the passband when the local oscillator signal has any first local oscillator frequency of the plurality;

and an upper and lower high frequency spectrum of interest translated to the passband when the local oscillator signal has any local oscillator frequency of the plurality other than the first local oscillator frequency of the plurality,

wherein the passband comprises a range of frequencies passed by a low pass filter and excluding DC and wherein the upper and lower high frequency spectra of interest translated with one local oscillator frequency are image signals one with respect to other.

14. The tuner of claim 13 wherein the continuous-time mixer comprises continuous-time quadrature mixers that provides I and Q signals in approximate quadrature relationship.

15. The tuner of claim 14 further comprising a digital signal processing device responsive to the I and Q signals to substantially reject either the translated lower high frequency spectrum of interest or the translated upper high frequency spectrum of interest.

16. The tuner of claim 15 wherein the digital signal processing device is structured and arranged to perform complex multiplication on the non-rejected translated spectrum of interest to effect frequency translation of a signal of interest from said spectrum of interest to baseband.

17. The tuner of claim 16 wherein the digital signal processing device is structured and arranged so as to be able to correct errors between the I and Q signals.

18. The tuner of claim 13 further comprising a digital signal processing portion including first and second analog-to-digital converters in the form of delta-sigma modulators each of which samples a signal mixed by the mixer, and wherein the delta-sigma modulators are each followed by a decimating filter.

19. A tuner comprising:

a local oscillator that provides a local oscillator signal having a frequency selected from a plurality of local oscillator frequencies and

a continuous-time mixer that mixes an incoming signal with the local oscillator signal so as to translate a lower high frequency spectrum of interest and an upper high frequency spectrum of interest to within a passband,

improved wherein the local oscillator frequencies of the plurality are spaced such that any high frequency spectral pair can be tuned from only one local oscillator frequency of the plurality and such that there is substantially no redundant spectral coverage between;

an upper and lower high frequency spectrum of interest translated to the passband when the local oscillator signal has any first local oscillator frequency of the plurality;

and an upper and lower high frequency spectrum of interest translated to the passband when the local oscillator signal has any local oscillator frequency of the plurality other than the first local oscillator frequency of the plurality,

wherein the passband comprises a range of frequencies passed by a low pass filter and excluding DC thereby minimizing noise and interference.

20. The tuner of claim 19 wherein the continuous-time mixer comprises continuous-time quadrature mixers that provides I and Q signals in approximate quadrature relationship.

21. The tuner of claim 20 further comprising a digital signal processing device responsive to the I and Q signals to substantially reject either the translated lower high frequency spectrum of interest or the translated upper high frequency spectrum of interest.

22. The tuner of claim 21 wherein the digital signal processing device is structured and arranged to perform complex multiplication on the non-rejected translated spectrum of interest to effect frequency translation of a signal of interest from said spectrum of interest to baseband.

23. The tuner of claim 22 wherein the digital signal processing device is structured and arranged so as to be able to correct errors between the I and Q signals.

24. The tuner of claim 19 further comprising a digital signal processing portion including first and second analog-to-digital converters in the form of delta-sigma modulators each of which samples a signal mixed by the mixer, and wherein the delta-sigma modulators are each followed by a decimating filter.