Parallel Figure-8 Inductor Layout for VCO Phase Noise Reduction

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Solution Overview

Problem

Voltage-controlled oscillators (VCOs) in mobile communication devices generate phase noise, which affects the performance and quality of wireless signals, and existing inductor designs face a trade-off between reducing phase noise and maintaining a high quality factor due to the relationship between inductance and power consumption.

Innovation Solution

A parallel figure-8 inductor configuration is introduced, where two coils are placed in parallel, resulting in a total inductance approximately half that of each coil, allowing for larger inductance and inner diameter, thereby increasing the quality factor and reducing phase noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If series inductor configuration is used, then inductance is increased, but quality factor decreases due to increased power consumption

Engineering Contradiction:
ImproveinductanceVSAvoidpower consumption
Core Design Contradiction:
Area of stationary objectVSLoss of energy

Solution Approach 1:

The inductor is divided into two separate coils instead of using a single series configuration. This segmentation allows the coils to be arranged in parallel, which changes the overall inductance calculation and reduces power consumption while maintaining adequate inductance for VCO operation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of connecting the coils in series to increase inductance, the patent inverts the connection topology to parallel. This inversion achieves the opposite electrical characteristic (lower equivalent inductance) but with the beneficial side effect of reduced power consumption and improved quality factor

Inventive Principle:
Principle #13The other way round (Inversion)

2Object-generated harmful factors

If larger inductance is used, then phase noise is reduced, but quality factor decreases

Engineering Contradiction:
Improvephase noiseVSAvoidquality factor
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The patent inverts the conventional approach by using parallel coil configuration instead of series. This inversion achieves lower equivalent inductance with reduced power consumption, which improves quality factor while still providing sufficient inductance to reduce phase noise in the VCO

Inventive Principle:
Principle #13The other way round (Inversion)

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 effectively reduces phase noise while maintaining a higher quality factor compared to series configurations, improving the overall performance of VCOs in mobile communication devices.

Implementation Method 1

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

Methodology Applied
Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Data Source

PatentEP4152604A1Inductor topology for phase noise reduction
Publication Date: 2023.03.22 APPLE INC
  • EP4152604A1 patent drawingFigure 1~2
  • EP4152604A1 patent drawingFigure 3~4
  • EP4152604A1 patent drawingFigure 5

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.