Variable Inductor With Switchable Secondary Conductors

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Solution Overview

Problem

Conventional variable inductors have limited adjustable inductance range, insufficient inductance resolution, lower Q value, durability issues, and bias concerns, which restrict their performance in integrated circuits.

Innovation Solution

A variable inductor design featuring a primary conductor and multiple secondary conductors with switches that form single-loop structures with changeable current paths, allowing for wider inductance adjustment and higher Q value by controlling the switches' states, integrated into a radio frequency integrated circuit using CMOS or PCB components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional variable inductor structures are used, then the device can be manufactured with existing technology, but the adjustable inductance range is limited and inductance resolution is insufficient

Engineering Contradiction:
Improveadjustable inductance rangeVSAvoidinductor structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The secondary conductor is divided into multiple segments with individual switches, allowing independent control of each segment. This segmentation enables fine-grained adjustment of the inductance by selectively connecting or disconnecting segments, thereby expanding the adjustable inductance range and improving resolution without requiring a completely new inductor architecture

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The inductor incorporates dynamically controllable switches that can change the circuit configuration in real-time. This dynamic switching capability allows the inductance value to be adjusted continuously or in discrete steps, transforming a static inductor into a variable one with expanded adjustment range while maintaining a relatively simple underlying structure

Inventive Principle:
Principle #15Dynamics

2Reliability

If conventional variable inductor designs are used, then the structure can be kept simple, but the Q value is lower and durability issues arise

Engineering Contradiction:
Improvedurability and Q valueVSAvoidinductor structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Switches are introduced as intermediary components between the conductors, allowing control of the inductance without directly modifying the conductor structure itself. This intermediary approach enables high Q values by keeping the conductor paths optimized for signal transmission while using the switches to control effective inductance, thereby improving reliability without significantly complicating the overall structure

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If conventional variable inductor structures are used, then manufacturing can proceed with standard processes, but bias concerns and durability issues persist

Engineering Contradiction:
Improveperformance capabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The design replaces mechanical adjustment mechanisms with electronic switching control. Instead of physically reconfiguring the inductor structure, solid-state switches electronically control the effective inductance, eliminating mechanical wear and bias issues while maintaining compatibility with standard integrated circuit manufacturing processes

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 design achieves a wider adjustable inductance range, improved inductance resolution, higher Q value, reduced durability issues, and eliminates bias concerns, enhancing the performance of the variable inductor in integrated circuits.

Implementation Method 1

The first secondary conductor magnetically couples to the primary conductor

Methodology Applied
Scientific EffectMagnetic coupling: Electromagnetic Induction

Data Source

PatentEP3503132B1Variable inductor and integrated circuit using the variable inductor
Publication Date: 2021.05.26 NAT CHUNG SHAN INST SCI & TECH
  • EP3503132B1 patent drawingFigure 1A~1B
  • EP3503132B1 patent drawingFigure 2
  • EP3503132B1 patent drawingFigure 3

AI summary

A variable inductor comprises a primary conductor, a first secondary conductor and one or more switch. The primary conductor has a first node and a second node, wherein the first node is used to connect a first external component and the second node is used to connect a second external component. The first secondary conductor magnetically couples to the primary conductor. The one or more switch has two sides connected to the first secondary conductor, respectively. The first secondary conductor is formed a single-loop structure with two or more changeable current paths which are operated by the states of the one or more switch. An integrated circuit using the variable inductor is also introduced.