Low-Loss MMIC to Waveguide Interface Using Step Launch

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Solution Overview

Problem

Current interfaces between monolithic microwave integrated circuits (MMICs) and waveguides experience significant signal loss due to impedance mismatches and the use of dielectric materials, leading to inefficiencies and increased costs, particularly at higher frequencies.

Innovation Solution

A low-loss interface using a step launch mechanism that directly connects MMICs to waveguides without dielectric materials, featuring a stepped transition to match impedance and wave mode propagation, constructed from conductive materials like gold or copper, and adjustable components to minimize signal loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If dielectric materials are used in the interface between MMIC and waveguide, then impedance matching is achieved, but signal loss increases due to dielectric losses and higher loss tangents at microwave frequencies

Engineering Contradiction:
Improvesignal lossVSAvoidinterface structure complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent removes dielectric materials from the interface structure between MMIC and waveguide. By extracting the harmful dielectric component, the interface achieves lower signal loss while maintaining impedance matching through a direct metal-to-metal stepped transition structure.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a stepped transition structure as an intermediary element between the MMIC transmission line and the waveguide. This stepped structure serves as a mediator that transforms impedance and wave mode without requiring dielectric materials, thereby reducing signal loss while achieving proper impedance matching.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If traditional interface structures with multiple components are used, then impedance matching is achieved, but manufacturing cost and production complexity increase

Engineering Contradiction:
Improveproduction costVSAvoidsignal loss
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The patent combines multiple functions (impedance matching, wave mode transformation, and mechanical support) into a single integrated stepped transition structure. This merging eliminates the need for separate dielectric materials and multiple components, reducing both manufacturing cost and signal loss while maintaining impedance matching capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The stepped transition structure serves multiple functions simultaneously: it provides impedance transformation, guides wave mode propagation, and acts as a mechanical support structure. This multi-functionality reduces the number of components needed, lowering production cost while maintaining low signal loss performance.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Quantity of substance

If impedance matching interfaces with multiple components are used, then impedance transformation is achieved, but the number of parts and materials increases

Engineering Contradiction:
Improvenumber of partsVSAvoidsignal loss
Core Design Contradiction:
Quantity of substanceVSLoss of energy

Solution Approach 1:

The patent extracts and removes dielectric materials from the interface structure, reducing the quantity of parts to only essential conductive elements. This extraction eliminates sources of dielectric loss while maintaining impedance matching through the stepped geometric transition.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the functions of multiple components (impedance matching elements, wave guides, and support structures) into a single integrated stepped transition structure, reducing the total number of parts while maintaining low signal loss performance.

Inventive Principle:
Principle #5Merging (Combining)

4Ease of manufacture

If dielectric materials are used for impedance matching, then impedance transformation is achieved, but production cost and material requirements increase

Engineering Contradiction:
Improveproduction costVSAvoidinterface structure complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent removes dielectric materials from the interface structure, eliminating the need to source, handle, and assemble dielectric components. This extraction simplifies the interface structure while reducing production cost associated with dielectric materials.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the geometric parameters of the transition structure (creating stepped sections with specific dimensions and angles) to achieve impedance matching without dielectric materials. This parameter-based approach simplifies manufacturing by using only conductive materials with standard geometric variations.

Inventive Principle:
Principle #35Parameter changes

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 signal loss and ripple, enabling more efficient energy transmission with minimal components and lower production costs, while maintaining thermal efficiency and compactness, even at higher frequencies.

Implementation Method 1

the impedance of the MMIC, for example fifty ohms, may not match the impedance of the connected waveguide, which is much higher, typically several hundred ohms higher than the impendence of the MMIC

Methodology Applied
Scientific EffectImpedance matching:

Implementation Method 2

The present invention generally relates to an interface for use, for example, between an integrated circuit and a waveguide. More particularly, the present invention relates to an impedance matching interface such as a step launch that transports or transforms energy from an integrated circuit

Methodology Applied
Scientific EffectElectromagnetic wave propagation:

Data Source

PatentEP2201679B1Low-loss interface
Publication Date: 2019.02.20 VIASAT INC
  • EP2201679B1 patent drawingFigure 1
  • EP2201679B1 patent drawingFigure 2
  • EP2201679B1 patent drawingFigure 3A

AI summary

In general, and in accordance with various exemplary embodiments of the present invention, a low-loss interface for connecting an integrated circuit such as a monolithic microwave integrated circuit to an energy transmission device such as a waveguide is disclosed. In one exemplary embodiment, an interface comprises a step launch. In another exemplary embodiment, the interface is adjustable. In yet another exemplary embodiment, an electrical system further comprises an isolation wall. In still yet another embodiment, numerous electrical circuits are combined with interfaces for increased power output.