RF Switch With Slot Line Pattern Unit For High Isolation

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Solution Overview

Problem

Existing RF switches for TDD systems face challenges in securing high isolation between transmission and reception paths, handling high-power signals, and maintaining stability due to heat generation, leading to system failures and quality deterioration.

Innovation Solution

A radio frequency (RF) switch incorporating a circulator with a slot line pattern unit and switching circuit, which uses microstrip and slot lines on a printed circuit board to achieve high isolation and efficient signal transmission or interception, allowing for external control and heat management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a semiconductor switch (PIN diode or FET) is used for high-speed switching, then switching speed is improved, but the switch cannot handle high power due to heat generation

Engineering Contradiction:
Improveswitching speedVSAvoidpower handling capability
Core Design Contradiction:
SpeedVSPower

Solution Approach 1:

The system is divided into two separate switches: a semiconductor switch (PIN diode or FET) optimized for high-speed switching, and a mechanical switch optimized for high-power handling. This segmentation allows each component to operate within its optimal performance range, with the semiconductor switch providing fast switching and the mechanical switch handling high power without excessive heat generation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The mechanical switch acts as an intermediary between the high-power transmission signal and the semiconductor switch. It isolates the semiconductor switch from direct exposure to high-power signals, allowing the semiconductor device to perform fast switching operations without being damaged by heat from high-power handling.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Power

If a mechanical switch is used for high power handling, then power handling capability is improved, but switching speed becomes slow

Engineering Contradiction:
Improvepower handling capabilityVSAvoidswitching speed
Core Design Contradiction:
PowerVSSpeed

Solution Approach 1:

The system divides the switching function between two specialized components: the mechanical switch handles power-intensive operations slowly but reliably, while the semiconductor switch handles speed-critical operations quickly but at lower power. This segmentation resolves the speed-power tradeoff by assigning tasks based on each component's strengths.

Inventive Principle:
Principle #1Segmentation

3Power

If an RF switch is designed for high power with separate cooling radiator, then power handling capability is improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvepower handling capabilityVSAvoiddevice complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The mechanical switch and semiconductor switch are integrated into a single unified RF switch device with shared housing and control mechanisms. This merging allows high power handling capability to be achieved through the mechanical switch component without requiring a separate cooling radiator system, thereby reducing overall device complexity and manufacturing difficulty while maintaining high-power performance.

Inventive Principle:
Principle #5Merging (Combining)

4Adaptability or versatility

If a circulator is used to separate transmission and reception signals, then signal separation is achieved, but isolation between transmission and reception paths is insufficient

Engineering Contradiction:
Improvesignal separation capabilityVSAvoidisolation between transmission and reception
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The dual-switch configuration acts as an intermediary mechanism that enhances the isolation capability of the circulator. By strategically placing switches in the signal path, the system achieves superior isolation between transmission and reception paths compared to the circulator alone, preventing transmission signals from leaking into the reception path during transmission sections.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 RF switch ensures high isolation, protects reception terminals from high-power signals, and enables stable operation even at high frequencies, improving communication quality and capacity while being easily manufacturable for microwave integrated circuits.

Implementation Method 1

a slot line pattern unit installed in a connection line between a third node of the circulator and a third port so as to carry out signal transmission or interception

Methodology Applied
Scientific EffectSlot line resonance:

Data Source

PatentEP2738947B1Radio frequency switch
Publication Date: 2019.01.30 KMW INC
  • EP2738947B1 patent drawingFigure 1~2
  • EP2738947B1 patent drawingFigure 3
  • EP2738947B1 patent drawingFigure 4

AI summary

Disclosed is a radio frequency (RF) switch including: a circulator having first to third nodes, which are connected to first to third ports, respectively; and a slot line pattern unit installed in a connection line between the third node of the circulator and the third port so as to carry out signal transmission or interception, wherein the slot line pattern unit includes a switching circuit, which is installed at a predetermined location so as to transmit or intercept a signal by maintaining or short-circuiting a gap of a slot line corresponding to the installed location according to an external switching control signal.