Oscillators having arbitrary frequencies and related systems and methods

• US 9,013,245 B2
• Filed: 06/18/2012
• Issued: 04/21/2015
• Est. Priority Date: 12/23/2009
• Status: Active Grant

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Sand 9, Inc. (Analog Devices, Inc.)
• Inventors: Rebel, Reimund, Schoepf, Klaus Juergen, Kuypers, Jan H.
• Primary Examiner(s): KINKEAD, ARNOLD M
• Application Number:
  US13/525,715
• Publication Number:
  US 20120315866A1
• Time in Patent Office: 1,037 Days
• Field of Search: 455/260, 375/219, 332/127, 327/105, 327/115
• US Class Current: 332/127
• CPC Class Codes: H03B 19/00 Generation of oscillations by non-regenerative frequency multiplication or division of a signal from a separate source transference of modulation from one carrier to another H03D7/00
• CPC Class Codes: H03B 5/30 with frequency-determining element being electromechanical resonator
• CPC Class Codes: H03B 5/32 being a piezoelectric resonator selection of piezoelectric material H10N30/00
• CPC Class Codes: H03C 3/095 applying frequency modulation to the loop in front of the voltage controlled oscillator
• CPC Class Codes: H03J 7/065 the counter or frequency divider being used in a phase locked loop
• CPC Class Codes: H03L 7/0991 the oscillator being a digital oscillator, e.g. composed of a fixed oscillator followed by a variable frequency divider H03L7/0995 takes precedence; fixed oscillators with means for selecting among various phases H03L7/0814
• CPC Class Codes: H03L 7/18 using a frequency divider or counter in the loop H03L7/20, H03L7/22 take precedence
• CPC Class Codes: H03L 7/197 a time difference being used for locking the loop, the counter counting between numbers which are variable in time or the frequency divider dividing by a factor variable in time, e.g. for obtaining fractional frequency division H03L7/1806 takes precedence
• CPC Class Codes: H04B 1/40 Circuits

Abstract

Systems and methods for operating with oscillators configured to produce an oscillating signal having an arbitrary frequency are described. The frequency of the oscillating signal may be shifted to remove its arbitrary nature by application of multiple tuning signals or values to the oscillator. Alternatively, the arbitrary frequency may be accommodated by adjusting operation one or more components of a circuit receiving the oscillating signal.

Claims

1. A method comprising:

downconverting a cellular telephone signal, the cellular telephone signal modulated with data, using an oscillating reference signal having an arbitrary frequency to generate a downconverted signal including the data; and

sampling the downconverted signal with an analog-to-digital converter (ADC) using a sampling rate selected to induce a shift of the data of the downconverted signal in a frequency domain,

wherein the arbitrary frequency differs from a standard oscillator frequency by between approximately 5,000 parts per million (ppm) and approximately 10,000 ppm.

2. The method of claim 1, further comprising receiving, from an oscillator having a mechanical resonator, the oscillating reference signal having an arbitrary frequency.

3. The method of claim 1, further comprising generating the oscillating reference signal from an oscillator output signal, wherein generating the oscillating reference signal comprises receiving, from an oscillator having a mechanical resonator, the oscillator output signal at a frequency synthesizer and synthesizing the oscillating reference signal, wherein the oscillating reference signal differs in frequency from a frequency of the oscillator output signal.

4. The method of claim 3, wherein the frequency synthesizer is a phase-locked loop (PLL).

5. The method of claim 1, further comprising receiving a value of the arbitrary frequency separate from the oscillating reference signal and selecting the sampling rate of the ADC in response to receiving the value.

6. A method comprising:

downconverting a first signal, the first signal modulated with data, using an oscillating reference signal having an arbitrary frequency to generate a downconverted signal including the data;

sampling the downconverted signal with an analog-to-digital converter (ADC) to produce a digital signal including digital data corresponding to the data; and

shifting, using a digital signal processor (DSP), the digital data in a frequency domain,

wherein the arbitrary frequency differs from a standard oscillator frequency by between approximately 500 parts per million (ppm) and 2,000 ppm, and wherein sampling the downconverted signal with an ADC comprises using a sampling rate corresponding to the standard oscillator frequency.

7. The method of claim 6, further comprising receiving the first signal modulated with data.

8. The method of claim 6, further comprising receiving, from an oscillator having a mechanical resonator, the oscillating reference signal having an arbitrary frequency.

9. The method of claim 6, further comprising generating the oscillating reference signal from an oscillator output signal.

10. The method of claim 9, wherein generating the oscillating reference signal comprises receiving, from an oscillator having a mechanical resonator, the oscillator output signal at a frequency synthesizer and synthesizing the oscillating reference signal, wherein the oscillating reference signal differs in frequency from a frequency of the oscillator output signal.

11. The method of claim 10, wherein the frequency synthesizer is a phase-locked loop (PLL).

12. The method of claim 6, wherein the first signal is a cellular telephone signal.