RF Switch with Magnetic Coupling for Linearity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Switches in microelectronics, particularly in radio communication devices, suffer from significant attenuation and non-linearity due to stray capacitance and diodes, which become more pronounced at high frequencies and in integrated circuits, affecting signal integrity and spectral purity.
Innovation Solution
A switch design featuring a terminal of one type and multiple terminals of another type, with magnetic coupling and reduced static switches to minimize non-linearity, eliminating the need for diodes and reducing stray capacitance, allowing for more linear behavior and improved high-frequency signal handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional static switches and diodes are used for switching and protection, then the switch can be configured and protected against electrostatic discharges, but significant attenuation and non-linearity occur at high frequencies due to stray capacitance
Solution Approach 1:
The patent removes the protective diodes from the high-frequency signal path entirely. Instead, protection is provided by a separate device with high impedance at operating frequencies, extracting the harmful diodes from the signal path while maintaining protection functionality through a different mechanism that doesn't introduce stray capacitance.
Solution Approach 2:
The patent introduces an intermediary protective device that presents high impedance at the operating frequency. This intermediary element provides electrostatic discharge protection without the stray capacitance problems of traditional diodes, acting as a mediator between protection requirements and high-frequency signal integrity.
2Adaptability or versatility
If traditional static switches are used for switching, then the switch can be configured to connect transmit and receive chains, but non-linearity increases due to stray capacitance in transistor junctions
Solution Approach 1:
The patent replaces traditional transistor-based static switches with a mechanical or electromagnetic relay structure. This substitution eliminates the junction capacitance inherent in transistors, providing linear switching without the non-linear effects that plague traditional semiconductor switches at high frequencies.
Solution Approach 2:
The patent changes the fundamental operating parameters of the switch by using a different switching mechanism with vastly different capacitance characteristics. The new switch design operates with negligible stray capacitance compared to traditional transistors, fundamentally altering the electrical parameters to achieve linearity.
3Device complexity
If the size of the circuit is reduced to integrate the switch in the amplifier's integrated circuit, then integration is achieved, but non-linearity becomes more considerable due to increased relative impact of stray capacitance
Solution Approach 1:
The patent replaces transistor-based switching with a relay or electromagnetic switch structure that can be integrated while maintaining low capacitance. This substitution allows integration into the amplifier circuit without the non-linearity problems that would be magnified in a compact integrated design.
4Power
If high power is handled by the switch located upstream from the transmit antenna, then the switch can handle high-power applications, but non-linearity and signal modification increase
Solution Approach 1:
The patent employs a relay or electromagnetic switch structure capable of handling high power without the junction capacitance effects that limit transistor performance at high power levels. This mechanical/electromagnetic approach maintains linearity even when handling significant power levels upstream from the antenna.
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 solution significantly reduces non-linear effects, enhances signal integrity, and minimizes radio frequency losses, making it suitable for high-power applications within integrated circuits and radio communication devices.
Implementation Method 1
Each of these second circuits comprises a portion that is magnetically coupled to the first circuit
Data Source
AI summary
Switch including a terminal of a first type and at least two terminals of a second type, and a number of circuits capable of ensuring exclusive connection of one of the terminals of the second type to the terminal of the first type as a function of a set of control orders wherein the terminal of the first type is connected to a common point by a first circuit; each terminal of the second type is connected to the common point by a second circuit, with each second circuit including a portion that is magnetically coupled to the first circuit, a static switch mounted in parallel with the portion and capable of being controlled in the “off” state in order to connect the terminal of the first type to the terminal of the second type associated with the second circuit in question.