Simplified high frequency tuner and tuning method

• US 20100184394A1
• Filed: 03/30/2010
• Published: 07/22/2010
• Est. Priority Date: 09/13/1996
• Status: Active Grant

• Current Assignee: Washington Research Foundation (University of Washington)
• Original Assignee: University of Washington
• Inventors: Suominen, Edwin A.
• Granted Patent: US 8,355,683 B2
• Time in Patent Office: Days
• US Class Current: 455/131
• 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

1-65. -65. (canceled)

66. A method for dynamically selecting high-side or low-side injection of local oscillator mixing signals to help reject images within a receiver, comprising:

providing a mixer configured to utilize a mixing signal to mix an input signal to a desired frequency;

receiving an RF signal spectrum including a plurality of channels;

identifying a channel within the RF signal spectrum to be tuned;

selecting high-side injection or low-side injection for the mixing signal;

generating a high-side local oscillation (LO) signal if high-side injection is selected, and generating a low-side local oscillation (LO) signal if low-side injection is selected;

and mixing the RF signal spectrum with the local oscillation signal that was selected and generated so as to mix the channel to be tuned down to the desired frequency;

low-IF conversion circuitry coupled to receive the low-IF signals from the mixer and configured to output digital signals, the low-IF conversion circuitry including first and second analog-to-digital converters coupled to the real and imaginary low-IF signals and configured to output real and imaginary digital signals;

a digital-signal-processor (DSP) coupled to receive the digital signal from the low-IF conversion circuitry and configured to demodulate the signal within the selected radio channel, to digitally tune the selected radio channel, and to output a digital signal, the DSP comprising an on-chip, general purpose, digital processor.

67. The method of claim 66, wherein the receiving, identifying, selecting, generating and mixing steps are performed within a single integrated circuit.

68. The method of claim 66, further comprising generating two phase shifted mixing signals for use by the mixer, the mixer operating to generate I and Q output signals.

69. The method of claim 66, wherein the desired frequency is a low-IF frequency.

70. The method of claim 69, wherein the receiving, identifying, selecting, generating and mixing steps are performed within a single integrated circuit.

71. The method of claim 66, wherein the RF signal spectrum comprises an RF terrestrial audio broadcast spectrum.

72. An integrated receiver, comprising:

a mixer coupled to receive an RF signal spectrum and a mixing signal as inputs and having a mixed signal as an output,

the RF signal spectrum comprising a plurality of channels;

local oscillator (LO) generation circuitry configured to provide an oscillation signal as an output,

the oscillation signal being used to generate the mixing signal for the mixer;

conversion circuitry coupled to receive the mixed signal from the mixer and configured to output a digital signal;

digital-signal-processor (DSP) circuitry coupled to receive the digital signal from the conversion circuitry and configured to output a tuned digital signal,

the DSP circuitry including tuning control coupled to the DSP and to the LO generation circuitry,

the tuning control being configured to select high-side or low-side injection of one or more frequencies within the RF signal spectrum,

and to control the LO generation circuitry to provide a high-side LO signal or a low-side LO signal depending upon the injection selection.

73. The integrated receiver of claim 72, further comprising quadrature generation circuitry configured to generate two phase shifted mixing signals for use by the mixer, the mixer operating to generate I and Q output signals.

74. The integrated receiver of claim 72, wherein the mixed signal is at low-IF frequency.

75. The integrated receiver of claim 72, wherein the RF signal spectrum comprises an RF terrestrial audio broadcast spectrum.

76. A mobile radio device having an integrated RF receiver, comprising:

a channel tuning interface;

a demodulated signal output interface, and

an integrated RF receiver coupled to the channel tuning interface and the demodulated signal interface, the RF receiver comprising;

a mixer coupled to receive a signal spectrum and a mixing signal as inputs and having a low-IF signal as an output, the signal spectrum comprising a radio broadcast signal comprising a plurality of radio channels from radio broadcasts, the mixer being configured to output real and imaginary low-IF signals;

local oscillator (LO) generation circuitry coupled to receive a radio channel tuning control as an input and configured to provide an oscillation signal, the oscillation signal being dependent upon the radio channel tuning control and being used to generate the mixing signal for the mixer;

quadrature generation circuitry configured to receive the mixing signal from the LO generation circuitry and to generate two phase shifted mixing signals for use by the mixer;

low-IF conversion circuitry coupled to receive the low-IF signals from the mixer and configured to output digital signals, the low-IF conversion circuitry including first and second analog-to-digital converters coupled to the real and imaginary low-IF signals and configured to output real and imaginary digital signals;

a digital-signal-processor (DSP) coupled to receive the digital signal from the low-IF conversion circuitry and configured to demodulate the signal modulation within the selected radio channel, to digitally tune the selected radio channel, and to output a digital signal, the DSP comprising an on-chip, general purpose, digital processor, and

circuitry coupled to receive the digital signal from the DSP and configured to output the demodulated signal;

wherein the mixer, the LO generation circuitry, the low-IF conversion circuitry, and the DSP including the frequency control circuitry are integrated within a single integrated circuit.

wherein the integrated circuit is made using a single-chip low-power implementation process.

77. An integrated radio receiver, comprising:

mixer circuitry coupled to receive an RF signal spectrum and phase shifted mixing signals as inputs and having a low-IF signal as an output, the RF input signal spectrum comprising a radio signal spectrum comprising a plurality of radio channels, the mixer circuitry being configured to output real and imaginary low-IF signals;

local oscillator (LO) generation circuitry configured to provide an oscillation signal, the oscillation signal being dependent upon the channel selection and being used to generate the phase shifted mixing signals for the mixer circuitry;

low-IF conversion circuitry coupled to receive the real and imaginary low-IF signals from the mixer circuitry and configured to output digital signals, the low-IF conversion circuitry including first and second analog-to-digital converters coupled to the real and imaginary low-IF signals and configured to output real and imaginary digital signals; and

digital-signal-processor (DSP) circuitry coupled to receive the digital signals from the low-IF conversion circuitry and configured to demodulate the selected radio channel, to digitally tune the selected radio channel, and to output demodulated signals; and

wherein the mixer circuitry, the LO generation circuitry, the low-IF conversion circuitry, and the DSP circuitry are integrated within a single integrated circuit.

78. A method for tuning terrestrial radio broadcasts in an integrated receiver, comprising:

generating an oscillation signal, the oscillation signal being dependent upon channel selection;

providing phase shifted mixing signals based upon the oscillation signal;

mixing an RF input signal spectrum with the phase shifted mixing signals to generate real and imaginary low-IF output signals, the RF input signal spectrum comprising a radio signal spectrum comprising a plurality of radio channels from radio broadcasts;

converting the low-IF output signals to real and imaginary digital signals; and

processing the digital signals utilizing digital signal processing (DSP) circuitry to demodulate a selected radio channel, to digitally tune the selected radio channel, and to output demodulated signals;

wherein the generating, providing, mixing, converting, processing and converting steps are performed within a single integrated circuit.

79. An integrated low intermediate frequency (low-IF) data receiver for radio broadcast channels, comprising:

analog receive path circuitry coupled to receive an RF (radio frequency) signal spectrum comprising a plurality of radio channels, the analog receive path circuitry being configured to mix the RF signal spectrum down to a low-IF frequency to produce down-converted signals and being further configured to use mixing signals having a frequency based upon a desired channel to be tuned;

digital conversion circuitry coupled to receive the down-converted signals and configured to produce digital output signals;

digital processing circuitry configured to receive the digital output signals, to digitally process the digital output signals to demodulate the signals associated with the desired channel, and to generate output signals associated with the desired channel; and

wherein the analog receive path circuitry, the digital conversion circuitry, and the digital processing circuitry are integrated within a single integrated circuit.

80. The method for receiving RF (radio frequency) data signals within radio broadcast channels, comprising:

receiving an RF (radio frequency) signal spectrum comprising a plurality of channels;

mixing the RF signal spectrum with mixing signals to mix the RF signal spectrum down to a low-IF frequency to produce down-converted signals, the mixing signals having a frequency based upon a desired channel to be tuned;

converting the down-converted signals to digital output signals;

digitally processing the digital output signals to demodulate signals associated with the desired channel and to generate output signals associated with the desired channel; and

wherein the receiving, mixing, converting, and digitally processing acts are performed within a single integrated circuit.