Parallel CMOS RF Switches with Matching Network

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Solution Overview

Problem

Current RF switching devices for portable radio communication sets face challenges in minimizing size, electrical consumption, and cost, with pin diode solutions being bulky and energy-intensive, and CMOS technology switches limited to four outputs.

Innovation Solution

Implementing CMOS technology switches in parallel configuration with a common matching network, allowing for multiple outputs without the need for high voltage power supplies, and using open-circuit channels to adapt to a wide frequency band.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If pin diodes are used for RF switching, then the number of outputs can be greater than four, but the device occupies large surface area and consumes high electrical power

Engineering Contradiction:
Improvenumber of outputsVSAvoidoccupied surface
Core Design Contradiction:
Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent divides the RF switching function into multiple independent CMOS switches (first switch and second switch) that operate in parallel. Each switch handles a subset of the total outputs, allowing the system to achieve more than four outputs while maintaining the compact size and low power consumption characteristics of individual CMOS switches.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If pin diodes are used for RF switching, then the number of outputs can be greater than four, but the electrical consumption increases significantly

Engineering Contradiction:
Improvenumber of outputsVSAvoidelectrical consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by stationary object

Solution Approach 1:

The patent divides the RF switching function into multiple independent CMOS switches (first switch and second switch) that operate in parallel. Each switch handles a subset of the total outputs, allowing the system to achieve more than four outputs while maintaining the compact size and low power consumption characteristics of individual CMOS switches.

Inventive Principle:
Principle #1Segmentation

3Area of stationary object

If CMOS technology switches are used, then size and power consumption are reduced, but the number of outputs is limited to four

Engineering Contradiction:
Improveoccupied surfaceVSAvoidnumber of outputs
Core Design Contradiction:
Area of stationary objectVSAdaptability or versatility

Solution Approach 1:

The patent combines multiple CMOS switches (first switch with four outputs and second switch with four outputs) in a parallel configuration where their output terminals are connected together. This merging allows the composite switching device to provide more than four outputs while maintaining the size and power consumption advantages of CMOS technology.

Inventive Principle:
Principle #5Merging (Combining)

4Use of energy by stationary object

If CMOS technology switches are used, then power consumption is reduced, but the number of outputs is limited to four

Engineering Contradiction:
Improveelectrical consumptionVSAvoidnumber of outputs
Core Design Contradiction:
Use of energy by stationary objectVSAdaptability or versatility

Solution Approach 1:

The patent combines multiple CMOS switches (first switch with four outputs and second switch with four outputs) in a parallel configuration where their output terminals are connected together. This merging allows the composite switching device to provide more than four outputs while maintaining the size and power consumption advantages of CMOS technology.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3182602B1Broadband RF switching device with multiple outputs and RF station using such a switch
Publication Date: 2021.07.28 THALES SA
  • EP3182602B1 patent drawingFigure 1
  • EP3182602B1 patent drawingFigure 2
  • EP3182602B1 patent drawingFigure 3~4

AI summary

The solution proposed by the invention consists of connecting several switches (31, 32) in parallel on the same RF channel, with each switch having one open-circuit output (311, 321). A matching network (33) is implemented between the "1-channel" inputs (310, 320) of the switches to adapt the operation over a wide frequency band, for example, in the VHF and UHF ranges. This matching network compensates, in particular, for disturbances caused by the open-circuit outputs. On each of the switches (31, 32), at least one channel (311, 321) is left open-circuit, the other outputs being intended to be connected to other RF functions. The open-circuit channel (321) is activated on the switches (32) whose channels are not in use; "activated" meaning that the switch input is routed to this open circuit. The switch (31) which contains the passing channel is programmed and used in a conventional manner.