Super-Regenerative Receiver Frequency Correction During Quench Phase
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Solution Overview
Problem
The resonant frequency of a voltage-controlled oscillator (VCO) in a super-regenerative receiver is modified during the quench phase due to changes in bias current, leading to frequency drift and reduced selectivity.
Innovation Solution
A correction method using a Voltage Control Oscillator bias current dependent varactor, calibrated at various bias current points, to adjust the resonant frequency by digitally storing corrections in a lookup table and applying them to the VCO correction varactor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the bias current is increased to start oscillation during the quench phase, then the oscillation signal amplitude increases, but the resonant frequency drifts due to modified inductor equivalent value and tank capacitance variations
Solution Approach 1:
The patent applies preliminary action by pre-calibrating the relationship between bias current and resonant frequency drift before operation. A lookup table is constructed during calibration that stores the cumulative frequency drift values at different bias current levels. During actual operation, this pre-computed correction data is directly applied to compensate for the frequency drift caused by bias current changes, eliminating the need for real-time complex calculations.
Solution Approach 2:
The patent implements feedback by continuously monitoring the actual resonant frequency during the quench phase and comparing it with the reference frequency. The frequency drift is measured and fed back to adjust the oscillator frequency through a correction mechanism. This closed-loop feedback ensures that despite bias current variations, the oscillator maintains accurate frequency alignment with the reference.
2Adaptability or versatility
If the bias current varies during the quench phase, then the oscillation can be started and stopped, but the internal oscillator nodes experience bias voltage variations that modify the equivalent total tank capacitance and resonant frequency
Solution Approach 1:
The patent applies preliminary action by pre-calibrating the relationship between bias current and resonant frequency drift before operation. A lookup table is constructed during calibration that stores the cumulative frequency drift values at different bias current levels. During actual operation, this pre-computed correction data is directly applied to compensate for the frequency drift caused by bias current changes, eliminating the need for real-time complex calculations.
Solution Approach 2:
The patent applies parameter changes by dynamically adjusting the oscillator frequency parameter in response to bias current variations. Instead of maintaining a fixed frequency, the system changes the frequency parameter based on the current bias level, using pre-calibrated correction data to ensure the frequency remains accurate despite the changing operating conditions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method effectively corrects frequency drift during the quench phase, maintaining the resonant frequency within a 0.99 to 1.01 ratio of the oscillator frequency actual value to the oscillator resonant frequency reference value, thereby enhancing the receiver's selectivity.
Implementation Method 1
A correction method using a Voltage Control Oscillator bias current dependent varactor, calibrated at various bias current points, to adjust the resonant frequency
Implementation Method 2
A voltage-controlled oscillator, VCO for short, is an oscillator whose frequency is determined by a control voltage
Implementation Method 3
the inductor circuit equivalent model gets a serial resistor, which represents rolled into one its metal resistance, the skin effect and the Eddy currents losses within the substrate
Implementation Method 4
the inductor circuit equivalent model gets a serial resistor, which represents rolled into one its metal resistance, the skin effect and the Eddy currents losses within the substrate
Data Source
AI summary
A correction method for a super-regenerative receiver being configured to resonate at at least one oscillator resonant frequency reference value and comprising at least one control stage, at least one varactor, at least one reference system and, at least one oscillator. The method includes at least one setup of at least one reference signal value by the at least one reference system, at least one comparison of at least one oscillator frequency actual value of the at least one oscillator with the at least one reference signal value by the at least one reference system and at least one adjustment of at least one gain of the at least one control stage.