Stacked Microstrip Waveguide Power Combiner for Low-Loss Size Reduction

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Solution Overview

Problem

Bracket-shaped power combiners used in radar and communication systems become large due to the size of the hollow waveguide, leading to increased loss and inefficiency in combining output powers from transistors.

Innovation Solution

A power combiner design featuring a first and second substrate with microstrip lines and a hollow waveguide with a metal film on its inner wall, where the microstrip lines overlap to reduce size and enhance power combination efficiency, utilizing a protrusion portion for low-loss electromagnetic wave conversion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a bracket-shaped power combiner with a large hollow waveguide is used, then the power combining function is achieved, but the device size becomes large

Engineering Contradiction:

Improvepower combining functionVSAvoiddevice size

Core Design Contradiction:

PowerVSArea of stationary object

Solution Approach 1:

The patent transitions from a planar microstrip line configuration to a three-dimensional stacked substrate configuration. Multiple substrates are stacked with microstrip lines on different layers, allowing power combining in a compact vertical arrangement rather than requiring a large horizontal waveguide structure. This dimensional change enables the same power combining function with significantly reduced device footprint.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent embeds multiple functional elements within a compact stacked structure. Microstrip lines, grounding conductors, and dielectric layers are nested across multiple substrate layers, with through-holes penetrating through the stacked substrates to connect corresponding conductive patterns. This nesting approach consolidates what would traditionally require a large planar waveguide into a compact multi-layer configuration.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Power

If a large hollow waveguide is used for power combining, then the power combining function is achieved, but energy loss increases

Engineering Contradiction:

Improvepower combining functionVSAvoidenergy loss

Core Design Contradiction:

PowerVSLoss of energy

Solution Approach 1:

The patent replaces the traditional large hollow waveguide structure with a microstrip line-based power combining mechanism. Instead of relying on a large metallic waveguide for electromagnetic wave propagation and power combining, the invention uses controlled impedance microstrip lines on stacked substrates with through-hole connections, achieving the same function with reduced energy loss.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the structural parameters of the power combining system by transitioning from a single-layer large-waveguide configuration to a multi-layer stacked microstrip configuration. This parameter change includes modifying the geometry, material distribution, and connectivity approach, resulting in reduced energy loss while maintaining the power combining function.

Inventive Principle:

Principle #35Parameter changes

3Quantity of substance

If microstrip lines are provided on both faces of a substrate for high density, then line density is improved, but electromagnetic wave guidance becomes complex

Engineering Contradiction:

Improvemicrostrip line densityVSAvoidelectromagnetic wave guidance complexity

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent divides the high-density microstrip line configuration into separate substrate layers. Instead of placing microstrip lines on both faces of a single substrate which creates complex electromagnetic coupling, the invention segments the structure into multiple substrates stacked vertically, with each substrate containing microstrip lines on one face. Through-holes provide controlled connections between layers, simplifying the electromagnetic wave guidance while maintaining high line density.

Inventive Principle:

Principle #1Segmentation

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 design reduces the size of the power combiner, minimizing loss and efficiently combining electric powers from transistors while maintaining low loss and compact dimensions.

Implementation Method 1

a hollow waveguide having a metal film on an inner wall of a hollow and coupled to the first microstrip line and the second microstrip line, the hollow waveguide combining a first electric power transmitted through the first microstrip line and a second electric power transmitted through the second microstrip line and transmitting a combined electric power

Methodology Applied

Scientific EffectWaveguide: Waveguide

Data Source

PatentUS11757167B2Waveguide power combiner formed with microstrip lines on first and second substrates, where aligned openings in the substrates are stacked to form the waveguide power combiner

Publication Date: 2023.09.12 FUJITSU LTD

AI summary

A power combiner includes a first substrate provided with a first microstrip line, a second substrate provided with a second microstrip line, and a hollow waveguide having a metal film on an inner wall of a hollow and coupled to the first microstrip line and the second microstrip line, the hollow waveguide combining a first electric power transmitted through the first microstrip line and a second electric power transmitted through the second microstrip line and transmitting a combined electric power.