Oscillators having arbitrary frequencies and related systems and methods

• US 8,704,604 B2
• Filed: 12/06/2011
• Issued: 04/22/2014
• Est. Priority Date: 12/23/2009
• Status: Active Grant

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Sand 9, Inc. (Analog Devices, Inc.)
• Inventors: Schoepf, Klaus Juergen, Rebel, Reimund, Kuypers, Jan H.
• Primary Examiner(s): Gannon, Levi
• Application Number:
  US13/312,220
• Publication Number:
  US 20120139647A1
• Time in Patent Office: 868 Days
• Field of Search: 331/2, 331 16- 18, 331/34, 331/44, 331 46- 48, 331/74, 331/154, 331/158, 455/164.1, 455/182.1, 455/192.1, 455/192.2, 455/125
• US Class Current: 331/158
• CPC Class Codes: H03B 5/32 being a piezoelectric resonator selection of piezoelectric material H10N30/00
• CPC Class Codes: H03J 7/065 the counter or frequency divider being used in a phase locked loop
• 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

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:

measuring a frequency of an oscillating transmitter output signal of a transmitter, the transmitter forming at least part of a transceiver comprising a local oscillator, the local oscillator having a mechanical resonating structure and being configured to produce an oscillating signal having a frequency exhibiting a fractional deviation from a nominal oscillator frequency;

calculating a scaling factor based on the nominal oscillator frequency of the local oscillator, the frequency of the transmitter output signal and a target frequency of the transmitter output signal; and

reducing a fractional deviation of the frequency of the transmitter output signal from the target frequency of the transmitter output signal by adjusting a setting of one or more components of the transmitter based on the scaling factor, independent of adjusting the fractional deviation of the frequency of the oscillating signal from the nominal oscillator frequency.

2. The method of claim 1, wherein the mechanical resonating structure comprises a quartz crystal resonator.

3. The method of claim 1, wherein a tuning signal is not applied to the local oscillator.

4. The method of claim 1, wherein adjusting a setting of one or more components of the transmitter comprises adjusting a sampling rate of a digital-to-analog converter.

5. The method of claim 1, wherein adjusting a setting of one or more components of the transmitter comprises adjusting a setting of a frequency synthesizer of the transmitter.

6. The method of claim 5, wherein the frequency synthesizer is a phase-locked loop (PLL) or a direct digital synthesizer (DDS).

7. The method of claim 6, wherein the frequency synthesizer is a direct digital synthesizer (DDS).

8. The method of claim 1, wherein said reducing results in a fractional deviation of the frequency of the oscillating transmitter output signal from the target frequency of less than 30 parts per million, and wherein the fractional deviation of the frequency of the oscillating signal of the local oscillator from the nominal oscillator frequency is greater than 100 parts per million.

9. The method of claim 8, wherein the fractional deviation of the frequency of the oscillating signal of the local oscillator from the nominal oscillator frequency is between 100 parts per million and 10,000 parts per million.

10. The method of claim 1, further comprising applying a tuning signal to the local oscillator.