Differential Oscillator Circuit With Fine Resonant Frequency Tuning
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Solution Overview
Problem
Conventional RF modulation systems suffer from poor precision, limited frequency adjusting rate, and low noise resistance due to their complexity, making them inadequate for high-resolution frequency modulation required in modern wireless communications.
Innovation Solution
The proposed solution involves an oscillator circuit with a passive network that includes multiple subnetworks connected to an active network, using variable capacitors and fixed capacitors in series to adjust resonant frequencies, allowing for coarse and fine adjustments, thereby increasing frequency-modulation resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional VCOs with variable capacitors and high precision DACs are used for frequency modulation, then frequency modulation capability is provided, but system complexity increases and precision deteriorates
Solution Approach 1:
The oscillator circuit is divided into multiple independent subnetworks (first subnetwork, second subnetwork, third subnetwork) each with specific capacitance adjustment functions. This segmentation allows precise frequency control through coordinated operation of simpler modular units rather than a single complex VCO system.
Solution Approach 2:
The patent implements a nested capacitor array structure where capacitor arrays are organized in multiple levels (first capacitor array, second capacitor array, third capacitor array) with varying bit weights. Each nested level contributes to the overall precision, with finer resolution at deeper levels, achieving high precision through hierarchical nesting rather than a single complex structure.
2Speed
If analog circuits are used for frequency control, then frequency modulation is achieved, but linearity deteriorates and frequency adjusting rate is limited
Solution Approach 1:
The patent replaces traditional analog voltage-controlled frequency adjustment with a digital control system. Digital control signals directly switch capacitor arrays on and off, eliminating the need for analog VCO circuits. This substitution provides superior linearity and faster adjustment rates since digital switching is instantaneous and highly linear, unlike analog continuous control.
3Object-affected harmful factors
If conventional RF modulation systems are used, then data transmission is enabled, but noise resistance performance deteriorates
Solution Approach 1:
The patent employs a differential oscillator architecture with complementary positive and negative oscillation paths. Each path has matching capacitor arrays and control circuits that generate differential output signals. This copying approach with differential signaling inherently rejects common-mode noise and interference, improving noise resistance while maintaining precise frequency modulation through the matched differential structure.
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
This approach significantly enhances frequency-modulation resolution by 20 times compared to conventional VCOs, improving precision and reducing system errors, enabling more accurate data transmission in wireless communications.
Implementation Method 1
adjust a central value of a resonant frequency of the oscillation
Implementation Method 2
The first subnetwork includes a first capacitor array, including a plurality of first capacitors having different bit weights
Data Source
AI summary
Embodiments of oscillator circuits for wireless transmission of data are disclosed herein. In one example, an oscillator circuit includes an active network and a passive differential network coupled to the active network is disclosed. The active network is configured to generate an active signal for sustaining oscillation of the oscillator circuit. The passive network includes a first subnetwork, a second subnetwork, a first inductor and a second inductor. The first subnetwork is configured to adjust a central value of a resonant frequency of the oscillation. The passive network further includes a second subnetwork configured to further adjust the resonant frequency of the oscillation.