Concurrent support for multiple frequency bands for satellite navigation signals

Patent metadata

Field	Value
Publication number	US-10177873-B1
Application number	US-201815971609-A
Country	US
Kind code	B1
Filing date	May 4, 2018
Priority date	May 4, 2018
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

A radio frequency (RF) receiver, for example a satellite positioning system receiver, can be configured to use a single phase locked loop for generating an oscillator signal to perform downconversion of signals in two different frequency bands using two or more local oscillators. A first RF signal portion includes a first signal band and undergoes double downconversion using a first mixer and a second mixer, while a second RF signal portion includes a second signal band and undergoes single downconversion using a single mixer. A controller is configured to determine a first oscillator divider value and a second oscillator divider value to avoid a jammer frequency and frequency dividers are used to generate the two or more local oscillators.

First claim

What is claimed is:

1. A method for processing a radio frequency (RF) signal received at one or more antennae, the method comprising:
receiving a first RF signal portion of the RF signal on a first signal path;
identifying a jammer frequency;
selecting a first oscillator divider value and a second oscillator divider value based on the identified jammer frequency;
dividing the frequency of an oscillator signal using the first oscillator divider value to generate a first local oscillator signal;
dividing the frequency of the oscillator signal using the second oscillator divider value to generate a second local oscillator signal;
performing a first downconversion of the first RF signal portion on the first signal path by mixing the first RF signal portion with the first local oscillator signal to generate a first downconversion output signal on the first signal path;
performing a second downconversion of the first downconversion output signal on the first signal path by mixing the first downconversion output signal with the second local oscillator signal to generate a second downconversion output signal on the first signal path; and
filtering the second downconversion output signal to isolate an in-band signal from a jammer signal.

2. The method of claim 1 , further comprising:
receiving a second RF signal portion of the RF signal on a second signal path; and
performing a single downconversion of the second RF signal portion on the second signal path by mixing the first RF signal portion with a single local oscillator signal.

3. The method of claim 2 , wherein the single local oscillator signal is generated by dividing a frequency of a main oscillator signal using a fixed divider value.

4. The method of claim 1 , further comprising amplifying the RF signal received at the one or more antennae using a wideband low noise amplifier.

5. The method of claim 4 , further comprising filtering the RF signal received at the one or more antennae using a dual-band bandpass filter before amplifying the RF signal.

6. The method of claim 1 , wherein receiving the RF signal at the one or more antennae comprises receiving a navigation signal from a same navigation satellite, wherein the same navigation satellite transmits signals in a first band and in a second band different from the first band.

7. The method of claim 6 wherein the first band is an L2 band or an L5 band and the second band is an L1 band.

8. A radio frequency (RF) receiver comprising:
a first signal path to receive a first RF signal portion;
a controller configured to determine a first oscillator divider value and a second oscillator divider value based on a jammer frequency;
a first frequency divider configured to output a first local oscillator signal by dividing a frequency of an oscillator signal by the first oscillator divider value;
a second frequency divider configured to output a second local oscillator signal by dividing the frequency of the oscillator signal by the second oscillator divider value;
a first mixer configured to downconvert the first RF signal portion on the first signal path by mixing the first RF signal portion with the first local oscillator signal to generate a first downconversion output signal on the first signal path;
a second mixer configured to downconvert the first downconversion output signal on the first path by mixing the first downconversion output signal with the second local oscillator signal to generate a second downconversion output signal on the first signal path; and
a filter configured to filter the second downconversion output signal on the first signal path to isolate an in-band signal from a jammer signal.

9. The RF receiver of claim 8 , further comprising:
a second signal path to receive a second RF signal portion; and
a diplexer configured to receive an input RF signal from a single antenna and to provide a first output and a second output, the first output comprising the first signal path for the first RF signal portion and the second output comprising the second signal path for the second RF signal portion.

10. The RF receiver of claim 9 , further comprising:
a single mixer configured to downconvert the second RF signal portion on the second signal path by mixing the first RF signal portion with a single local oscillator signal.

11. The RF receiver of claim 10 , further comprising:
a divider configured to divide a frequency of a main oscillator signal by a fixed oscillator divider value.

12. The RF receiver of claim 9 , further comprising:
a low noise amplifier disposed after the single antenna and the diplexer and before the first mixer; and
an other low noise amplifier disposed after the diplexer and before the single mixer.

13. The RF receiver of claim 8 , further comprising:
a second signal path to receive a second RF signal portion;
a dual-band bandpass filter disposed between the single antenna and a wideband low noise amplifier, the wideband low noise amplifier comprising an output connected to the first signal path and the second signal path.

14. The RF receiver of claim 8 , wherein the controller, the oscillator signal, the first frequency divider, and the second frequency divider are together configured such that the frequency of the first local oscillator frequency and the second local oscillator frequency are together appropriate for downconverting an L5 or an L2 band to an intermediate frequency (IF) that is one of zero intermediate frequency (ZIF), very low IF (VLIF), low IF (LIF), or an IF less than 50 MHz.

15. The RF receiver of claim 8 , wherein the RF receiver is disposed within a mobile device.

16. An apparatus for processing a radio frequency (RF) signal received at one or more antennae, the apparatus comprising:
a first signal path;
means for identifying a jammer frequency;
means for selecting a first oscillator divider value and a second oscillator divider value based on the identified jammer frequency;
means for dividing the frequency of an oscillator signal using the first oscillator divider value to generate a first local oscillator signal;
means for dividing the frequency of the oscillator signal using the second oscillator divider value to generate a second local oscillator signal;
means for performing a first downconversion of the first RF signal portion on the first signal path by mixing the first RF signal portion with the first local oscillator signal to generate a first downconversion output signal on the first signal path;
means for performing a second downconversion of the first downconversion output signal on the first signal path by mixing the first downconversion output signal with the second local oscillator signal to generate a second downconversion output signal on the first signal path; and
means for filtering the second downconversion output signal to isolate an in-band signal from a jammer signal.

17. The apparatus of claim 16 , further comprising:
a second signal path; and
means for performing a single downconversion of the second RF signal portion on the second signal path by mixing the first RF signal portion with a single local oscillator signal.

18. The apparatus of claim 17 , wherein the single local oscillator signal is generated by dividing a frequency of a main oscillator signal using a fixed divider value.

19. The apparatus of claim 16 , further comprising means for amplifying the RF signal received at the one or more antennae using a wideband low noise amplifier.

20. The apparatus of claim 19 , further comprising me

Assignees

• Qualcomm Inc

Inventors

• Zeng Yi
• Kim Hong Sun
• Wang Cheng-Han

Classifications

• H04K3/228

  Elimination in the received signal of jamming or of data corrupted by jamming (interference suppression in receivers H04B1/10) · CPC title

• H03H11/346

  particularly adapted as input circuit for receivers · CPC title

• H03F3/19

  with semiconductor devices only · CPC title

• H03D7/165

  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 title

• H03F2200/451

  the amplifier being a radio frequency amplifier · CPC title