FREQUENCY-MODULATED CARRIER RECEIVER USING INJECTION-LOCKED OSCILLATOR

• US 20160365994A1
• Filed: 06/10/2015
• Published: 12/15/2016
• Est. Priority Date: 06/10/2015
• Status: Abandoned Application

• Current Assignee: Richtek Technology Corporation (MediaTek, Inc.)
• Original Assignee: Richtek Technology Corporation (MediaTek, Inc.)
• Inventors: CHEN, Sheng-Tsung, HUANG, Yen-Yin, YU, Ming-Shih
• Application Number:
  US14/735,672
• Publication Number:
  US 20160365994A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H03D 3/24 Modifications of demodulators to reject or remove amplitude variations by means of locked-in oscillator circuits
• CPC Class Codes: H04L 27/14 Demodulator circuits; Receiver circuits
• CPC Class Codes: H04L 27/16 Frequency regulation arrangements

Abstract

A frequency-modulated carrier receiver includes a signal extractor and an injection-locked oscillator. The signal extractor is configured to operably receive a frequency-modulated carrier and generate an injection signal based on the frequency-modulated carrier, so that the injection signal has a relatively smaller frequency variation than the frequency-modulated carrier. The injection-locked oscillator is coupled with the signal extractor and configured to operably filter out noise components in the injection signal to generate an output signal.

Claims

1. A frequency-modulated carrier receiver (100), comprising:

a signal extractor (110), configured to operably receive a frequency-modulated carrier (Fin) and generate an injection signal (Sin) based on the frequency-modulated carrier (Fin), so that the injection signal (Sin) has a relatively smaller frequency variation than the frequency-modulated carrier (Fin); and

an injection-locked oscillator (120), coupled with the signal extractor (110), configured to operably conduct a band-pass filtering operation on the injection signal (Sin) to filter out noise components from the injection signal (Sin) to generate an output signal (Fout) having same frequency of a target frequency signal (Ft) in the frequency-modulated carrier (Fin).

2. The frequency-modulated carrier receiver (100) of claim 1, wherein the signal extractor (110) comprises:

a differentiator (212), configured to operably generate a differentiation signal (Fin′

) based on the frequency-modulated carrier (Fin); and

a comparison circuit (214), coupled with the differentiator (212), configured to operably compare the differentiation signal (Fin′

) with a reference signal (REF) to generate the injection signal (Sin).

3. The frequency-modulated carrier receiver (100) of claim 2, wherein the reference signal (REF) corresponds to a DC output of the differentiator (212).

4. The frequency modulated carrier receiver (100) of claim 1, A frequency-modulated carrier receiver (100), comprising:

a signal extractor (110), configured to operably receive a frequency-modulated carrier (Fin) and generate an injection signal (Sin) based on the frequency-modulated carrier (Fin), so that the injection signal (Sin) has a relatively smaller frequency variation than the frequency-modulated carrier (Fin); and

an injection-locked oscillator (120), coupled with the signal extractor (110), configured to operably filter out noise components from the injection signal (Sin) to generate an output signal (Fout) having same frequency of a target frequency signal (Ft) in the frequency-modulated carrier (Fin);

wherein the signal extractor (110) comprises;

a delay circuit (312), configured to operably generate a delayed signal (Fd) based on the frequency-modulated carrier (Fin); and

a subtraction circuit (314), coupled with the delay circuit (312), configured to operably generate the injection signal (Sin) based on the frequency-modulated carrier (Fin) and the delayed signal (Fd).

5. The frequency-modulated carrier receiver (100) of claim 4, wherein the delay circuit (312) delays the frequency-modulated carrier (Fin) by a half signal period of the frequency-modulated carrier (Fin) to generate the delayed signal (Fd).

6. A frequency-modulated carrier receiver (100), comprising:

a signal extractor (110), configured to operably receive a frequency-modulated carrier (Fin) and generate an injection signal (Sin) based on the frequency-modulated carrier (Fin), so that the injection signal (Sin) has a relatively smaller frequency variation than the frequency-modulated carrier (Fin); and

an injection-locked oscillator (120), coupled with the signal extractor (110), configured to operably filter out noise components from the injection signal (Sin) to generate an output signal (Fout) having same frequency of a target frequency signal (Ft) in the frequency-modulated carrier (Fin);

wherein the signal extractor (110) comprises;

an analog-to-digital converter (412), configured to operably convert the frequency-modulated carrier (Fin) into a digital signal (DS);

a value detecting circuit (414), coupled with the analog-to-digital converter (412), configured to operably detect signal values of the digital signal (DS) to generate a control signal (CTL) for representing peak positions or valley positions of the frequency-modulated carrier (Fin); and

a signal generating circuit (416), coupled with the value detecting circuit (414), configured to operably generate the injection signal (Sin) according to the control signal (CTL).

7. The frequency-modulated carrier receiver (100) of claim 6, wherein when the value detecting circuit (414) detects that a signal value of the digital signal (DS) is greater than a peak threshold, the value detecting circuit (414) generates an active pulse in the control signal (CTL) to represent a peak position of the frequency-modulated carrier (Fin).

8. The frequency-modulated carrier receiver (100) of claim 6, wherein when the value detecting circuit (414) detects that a signal value of the digital signal (DS) is lower than a valley threshold, the value detecting circuit (414) generates an active pulse in the control signal (CTL) to represent a valley position of the frequency-modulated carrier (Fin).

9. A frequency-modulated carrier receiver (500), comprising:

an injection-locked oscillator (120), configured to operably receive a frequency-modulated carrier (Fin) and to operably conduct a band-pass filtering operation on the frequency-modulated carrier (Fin) to filter out noise components from the frequency-modulated carrier (Fin) to generate an output signal (Fout) having same frequency as a target frequency signal (Ft) in the frequency-modulated carrier (Fin).