Semiconductor Waveguide Assembly for Photoconductive RF Impedance Control

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Solution Overview

Problem

Existing waveguide switches for RF signals at mm-wave frequencies are large, heavy, and difficult to integrate with planar microwave technology, and existing optical control methods face reliability and stiction issues for high power applications.

Innovation Solution

A waveguide assembly integrated with a semiconductor wafer, featuring a waveguide channel with metallic-lined internal walls and semiconductor obstacle members that respond to electromagnetic radiation to vary impedance, allowing for switching, attenuating, and routing RF signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional metal-machined waveguides are used for waveguide switches, then low insertion loss and high power handling are achieved, but the devices become large, heavy, and difficult to integrate with planar microwave technology

Engineering Contradiction:

Improveinsertion loss and power handlingVSAvoidintegration difficulty and size

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the waveguide structure with planar microwave technology by integrating a waveguide switch into a substrate that supports both waveguide components and planar circuit elements. This allows the system to maintain the low insertion loss and high power handling of waveguides while achieving the compact size and integration capabilities of planar technology.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent implements nesting by placing the waveguide switch structure within a larger substrate that contains both waveguide and planar components. The waveguide channel is formed within the substrate, with metallic layers and semiconductor elements nested within the waveguide structure, allowing multiple functions to be integrated in a compact form factor.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Device complexity

If RF MEMS waveguide switches are used, then integration with planar technology is improved, but self-actuation, reliability, and stiction issues limit use for high power applications

Engineering Contradiction:

Improveintegration capabilityVSAvoidstiction and high power handling

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent replaces the mechanical RF MEMS actuation system with an electromagnetic field-based control mechanism. Instead of using mechanical moving parts that suffer from stiction and reliability issues, the invention uses a semiconductor obstacle member whose electrical properties are modulated by electromagnetic radiation, eliminating mechanical contact and associated problems while maintaining integration capabilities.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Speed

If optical control methods are used for waveguide switching, then high power handling and fast switching times are achieved, but bias network isolation and plasma element reliability remain challenges

Engineering Contradiction:

Improveswitching timeVSAvoidbias network isolation and plasma stability

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The patent introduces an intermediary semiconductor obstacle member that is controlled by electromagnetic radiation but does not require direct optical-bias network coupling. The semiconductor material acts as a mediator that converts optical control signals into electrical property changes, providing isolation between the optical control path and the RF signal path while maintaining fast switching response.

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 system provides low insertion loss, high power handling, and fast switching times, enabling efficient control of RF signals in the mm-wave range with improved integration and reliability.

Implementation Method 1

the semiconductor obstacle member is responsive to applied electromagnetic radiation to vary electrical conductance of the obstacle member

Methodology Applied

Scientific EffectPhotoconductivity: Photoconductivity

Data Source

PatentUS12426383B2Semiconductor system with waveguide assembly with RF signal impedance controllable by applied electromagnetic radiation

Publication Date: 2025.09.23 PURDUE RES FOUND

AI summary

A waveguide assembly integrated with a semiconductor wafer is provided. The waveguide assembly includes a waveguide channel defined by internal walls of the wafer lined with a metallic layer, and having at least one port for transmission of the RF signal into or out of the waveguide channel. The waveguide assembly also includes a semiconductor obstacle member disposed in the waveguide channel. The waveguide assembly may be fabricated using etching and deposition processes for semiconductor devices. In use, selectively varying either one or both of frequency or power level of electromagnetic radiation applied to the obstacle member varies electrical conductance of the obstacle member, and thereby varies the electrical impedance of the obstacle member to transmission of the RF signal through the waveguide channel. The waveguide assembly may be used for switching, attenuating, routing, filtering, and transforming the RF signal.