Parallel Figure-8 Inductor Topology for Lower VCO Phase Noise
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Solution Overview
Problem
Voltage-controlled oscillators (VCOs) in mobile communication devices generate phase noise, affecting the performance and quality of wireless signals, and existing inductor topologies face challenges in balancing inductance and quality factor to effectively reduce this noise.
Innovation Solution
A parallel figure-8 inductor configuration is introduced, where two coils are placed in parallel, resulting in a total inductance approximately half of each coil's inductance, allowing for larger inductance and inner diameter, thereby increasing the quality factor and reducing phase noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a series inductor configuration is used, then the total inductance is increased, but the quality factor decreases and phase noise increases
Solution Approach 1:
The inductor is segmented into two separate coils instead of using a single continuous winding. These two coils are arranged in parallel configuration, which fundamentally changes the inductance calculation and allows for larger individual coil dimensions while maintaining lower total inductance. This segmentation enables the achievement of both high quality factor and controlled inductance values.
Solution Approach 2:
Instead of connecting coils in series to increase inductance (conventional approach), the patent inverts the connection topology by using parallel configuration. This inversion allows the inductor to achieve larger physical dimensions with larger inner diameters, which improves the quality factor while the parallel connection naturally reduces the total inductance to approximately half of each individual coil's inductance.
2Area of stationary object
If the inductor inner diameter is decreased to reduce inductance, then the quality factor decreases, but phase noise reduction is needed
Solution Approach 1:
The patent inverts the conventional approach by increasing the inner diameter instead of decreasing it. The parallel configuration of two coils with larger inner diameters achieves the desired lower inductance value while simultaneously improving the quality factor, as larger diameters reduce resistive losses and improve magnetic field distribution.
Solution Approach 2:
The patent changes the fundamental parameters of the inductor design by using parallel connection topology and larger coil dimensions. This parameter change transforms the relationship between inductance and quality factor, allowing both parameters to be optimized simultaneously rather than requiring a trade-off between them.
3Speed
If larger inductance is used in VCO, then the oscillation frequency can be controlled, but phase noise is generated that affects signal quality
Solution Approach 1:
The patent inverts the conventional inductor design approach by using parallel coil configuration with larger dimensions. This inversion reduces the total inductance to approximately half of each coil's inductance while improving the quality factor, thereby reducing phase noise generation in the VCO while maintaining frequency control capability.
Solution Approach 2:
The patent creates a composite inductor structure using two separate coils in parallel configuration. This composite structure combines the advantages of larger coil dimensions (higher quality factor) with the benefits of parallel connection (lower total inductance), resulting in reduced phase noise while maintaining VCO frequency control.
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 parallel figure-8 inductor configuration achieves lower phase noise and higher quality factor compared to series configurations, improving the efficiency of VCOs by decreasing inductance while maintaining flux cancellation.
Implementation Method 1
The inductor may include a first coil coupled to the first terminal that extends in a counter-clockwise direction from the first terminal to the shared branch. The inductor may further include a second coil coupled to the first terminal that extends in a clockwise direction from the first terminal to the shared branch
Data Source
AI summary
A voltage-controlled oscillator may include an inductor. The inductor may include a first coil coupled to an electronic component. The inductor may include a first coil coupled to the first circuit component, a second coil coupled to the first circuit component via a junction and being in parallel with the first coil, and a shared circuit path coupled to the second circuit component, the first coil, and the second coil, the shared circuit path overlapping the junction. The inductor may be configured to reduce phase noise generated by the electronic component.