Quadrature Oscillator Current-Control Cross-Coupling for Low Phase Noise
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Solution Overview
Problem
Existing quadrature oscillator circuitry suffers from increased power consumption and phase noise due to the addition of active Gm-cells, which deteriorate oscillator performance.
Innovation Solution
The implementation of a cross-coupling circuit with current-control devices and transistors that control current based on common-mode voltage signals to achieve antiphase common-mode voltage signals, reducing the need for additional active components and minimizing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If active Gm-cells are added to achieve quadrature oscillation, then quadrature signal generation is enabled, but power consumption increases and phase noise deteriorates
Solution Approach 1:
The patent extracts and removes the active Gm-cells from the quadrature oscillator circuit, replacing them with passive cross-coupling mechanisms. This extraction eliminates the harmful power consumption and phase noise introduced by active components while preserving the quadrature signal generation capability through alternative passive coupling methods.
Solution Approach 2:
The patent introduces passive cross-coupling circuits as intermediary elements between the differential oscillator circuits. These passive cross-coupling circuits mediate the interaction between oscillators to achieve quadrature relationships without requiring active Gm-cells, thereby reducing power consumption and phase noise while maintaining functionality.
2Adaptability or versatility
If active Gm-cells are added to achieve quadrature oscillation, then quadrature signal generation is enabled, but phase noise increases
Solution Approach 1:
The patent extracts and removes the active Gm-cells that generate phase noise, replacing them with passive cross-coupling mechanisms. This extraction eliminates the harmful phase noise while preserving the quadrature signal generation capability through alternative passive coupling methods.
Solution Approach 2:
The patent replaces complex active Gm-cells with simpler passive cross-coupling circuits that do not require continuous power supply or active regulation. These passive elements inherently generate less phase noise and can be implemented with simpler, more reliable components.
3Adaptability or versatility
If additional active components are added for cross-coupling, then quadrature control is achieved, but device complexity increases
Solution Approach 1:
The patent extracts and removes the complex active Gm-cells from the cross-coupling mechanism, replacing them with simpler passive cross-coupling circuits. This extraction reduces device complexity while maintaining quadrature control capability through alternative passive methods.
Solution Approach 2:
The patent introduces passive cross-coupling circuits as intermediary elements that simplify the overall circuit architecture. These passive intermediaries achieve quadrature control without requiring complex active components, thereby reducing device complexity while preserving functionality.
Data Source
AI summary
Quadrature oscillator circuitry, comprising: a first differential oscillator circuit having differential output nodes and configured to generate a first pair of differential oscillator signals at those output nodes, respectively; a second differential oscillator circuit having differential output nodes and configured to generate a second pair of differential oscillator signals at those output nodes, respectively; and a cross-coupling circuit connected to cross-couple the first and second differential oscillator circuits. The cross-coupling circuit may comprise a pair of cross-coupled transistors.