Digital Phase Shift Circuit With Variable Inductors Across Frequency Bands

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing digital phase shift circuits exhibit frequency dependence in phase shift amount, leading to inconsistent performance across different frequency bands used by telecommunications carriers.

Innovation Solution

Incorporation of variable inductors in the circuit design to adjust phase shift amounts optimally for each frequency band, utilizing electronic switches and control units to manage inductance modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a digital phase shift circuit uses fixed inductors and capacitors, then the circuit structure is simple, but the phase shift amount exhibits frequency dependence and cannot be optimized for different frequency bands

Engineering Contradiction:
Improvephase shift amount adjustment for each frequency bandVSAvoidcircuit structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by replacing fixed inductors with variable inductors that can change their inductance values based on control signals. The variable inductor includes switching elements that connect different inductor portions to the circuit, allowing the inductance to be dynamically adjusted according to the frequency band, thereby resolving the frequency dependence issue while maintaining a manageable circuit structure through controlled variability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies the parameter changes principle by modifying the inductance parameter of the inductor component. By using variable inductors with switchable inductance values, the circuit can change the inductance parameter to match different frequency bands, enabling optimal phase shift performance across multiple frequencies without requiring completely different circuit designs for each band.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If variable inductors are added to adjust phase shift for each frequency band, then phase shift optimization is achieved, but circuit complexity increases

Engineering Contradiction:
Improvephase shift amount precisionVSAvoidcircuit structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies the segmentation principle by dividing the variable inductor into multiple discrete inductor portions (e.g., L1, L2, L3) that can be independently switched into the circuit. This segmentation allows precise control over the total inductance value by selecting specific combinations of inductor portions, thereby achieving accurate phase shift adjustment while keeping each individual switching element simple and manageable.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies the dynamics principle by implementing switching elements that can dynamically reconfigure the inductor connections based on the desired frequency band. This dynamic reconfiguration enables the circuit to adapt its inductance value in real-time, achieving precise phase shift control for different frequencies without requiring manual circuit redesign.

Inventive Principle:
Principle #15Dynamics

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 phase shift amount can be precisely adjusted across various frequency bands, ensuring consistent performance and optimal phase shift in digital phase shift circuits.

Implementation Method 1

a second circuit (200, 200A, 200B) connected to the first circuit and a common return line (L0) and including a variable inductor (202, 212, 222, 241, ID1 to ID6) configured to adjust a phase shift amount for each frequency band

Methodology Applied
Scientific EffectInductance variation: Inductor

Data Source

PatentEP4641926A1Digital phase shifting circuit
Publication Date: 2025.10.29 FUJIKURA LTD
  • EP4641926A1 patent drawingFigure 1
  • EP4641926A1 patent drawingFigure 2
  • EP4641926A1 patent drawingFigure 3A~3B

AI summary

A digital phase shift circuit includes a first circuit connected between a first port and a second port, and a second circuit connected to the first circuit and a common return line and including a variable inductor configured to adjust a phase shift amount for each frequency band.