Voltage controlled oscillator pulling reduction
AssigneeShenzhen Goodix Technology Co., Ltd.
InventorsAhmed Emira, Faisal Hussein
Life of this patent
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Abstract
Techniques are described for reducing frequency pulling in voltage-controlled oscillator (VCO) circuits. Some embodiments operate in context of a transmitter having a VCO and a power amplifier (PA), where resonant components of the VCO are impacted by magnetically coupled feedback from resonant components of the PA. The VCO and PA are coupled via a set of signal path components that cause signal path delay, such that the feedback signal is phase-delayed with respect to the signal generated by the VCO. A coupling delay matching system is used to introduce additional delay, thereby further phase-shifting the feedback signal to an integer multiple of the oscillation period of the VCO signal; thereby reducing frequency pulling of the VCO.
Claims20
A coupling delay matching (CDM) system comprising:
- a delay detector configured to detect a phase delay between a power amplifier (PA) signal and a voltage-controlled oscillator (VCO) signal, the delay detector comprising:
- a first output node coupled configured to couple with a signal path to inject a test signal into the signal path to generate an injected instance of the test signal, the signal path coupling the PA with the VCO, such that the injected instance of the test signal manifests on the PA signal;
- a first input node configured to couple with the signal path to detect a received instance of the test signal on the signal path as received from the VCO after magnetic coupling of the PA with the VCO causes the received instance of the test signal to manifest on the VCO signal;
- and
- a second output node configured to couple with a variable delay component to configure the variable delay component to introduce a signal delay onto the signal path that compensates for the detected phase delay, the phase delay detected as the phase delay between the injected instance of the test signal and the received instance of the test signal.
A method for coupling delay matching responsive to a phase delay between a power amplifier (PA) signal and a voltage-controlled oscillator (VCO) signal, the method comprising:
- injecting a test signal into a signal path to generate an injected instance of the test signal, the signal path coupling the PA with the VCO, such that the injected instance of the test signal manifests on the PA signal;
- detecting a received instance of the test signal on the signal path as received from the VCO after magnetic coupling of the PA with the VCO causes the received instance of the test signal to manifest on the VCO signal;
- and
- configuring a variable delay component to introduce a signal delay onto the signal path that compensates for the detected phase delay, the phase delay detected as the phase delay between the injected instance of the test signal and the received instance of the test signal.
Dependencies are inferred from the claim text.