Array Antenna Waveguide Layout for Higher Gain in Compact Modules

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Solution Overview

Problem

There is a contradiction between improving the gain of an array antenna and reducing the size of the antenna module, as increasing the area of the array antenna for gain enhancement contradicts the need for size reduction.

Innovation Solution

An antenna device is designed with a housing, an array antenna, and a waveguide where the waveguide is coupled to the antenna elements, with the housing-side end face of the waveguide having a greater length than the antenna-side end face, expanding the effective area for secondary waves and improving gain without increasing the module's size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the area of the array antenna is increased to improve gain, then the antenna gain is improved, but the size of the antenna module increases

Engineering Contradiction:

Improveantenna gainVSAvoidsize of antenna module

Core Design Contradiction:

PowerVSArea of stationary object

Solution Approach 1:

The waveguide extends in the depth direction (third dimension) from the antenna element toward the inside surface of the housing. By utilizing the depth dimension rather than expanding the antenna area in the plane, the effective radiating area is increased without increasing the footprint of the antenna module, thus resolving the contradiction between gain improvement and size reduction.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The waveguide acts as an intermediary structure between the antenna element and the housing. It couples to the antenna element and extends toward the housing, serving as a mediator that transforms the compact antenna structure into an extended effective radiating structure, thereby improving gain without increasing the overall module size.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Power

If the waveguide extends longer toward the housing to expand effective area, then antenna gain is improved, but the waveguide may interfere with other components in the housing

Engineering Contradiction:

Improveantenna gainVSAvoidspatial arrangement complexity

Core Design Contradiction:

PowerVSDevice complexity

Solution Approach 1:

The waveguide is positioned and dimensioned to have different end face lengths at different locations. The housing-side end face has a greater length in the first direction than the antenna-side end face, creating a tapered or asymmetric structure that optimizes the secondary wave source distribution while accommodating spatial constraints within the housing.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The waveguide exhibits asymmetric geometry with the housing-side end face being longer than the antenna-side end face in the first direction. This asymmetric design allows the waveguide to maximize its effective area for gain improvement while adapting to the asymmetric spatial constraints imposed by the housing and other components.

Inventive Principle:

Principle #4Asymmetry

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 expanded area of the waveguide's end face serves as a source of secondary waves, enhancing antenna gain while maintaining the module's dimensions, and the use of dielectric materials reduces impedance mismatch and improves heat dissipation.

Implementation Method 1

The end face of the waveguide that faces the inside surface of the housing serves as a source of secondary waves

Methodology Applied

Scientific EffectSecondary waves:

Implementation Method 2

the use of dielectric materials reduces impedance mismatch

Methodology Applied

Scientific EffectImpedance mismatch reduction: Dielectric

Implementation Method 3

the use of dielectric materials reduces impedance mismatch and improves heat dissipation

Methodology Applied

Scientific EffectHeat dissipation: Conduction (thermal)

Data Source

PatentUS12586928B2Antenna device and communication device

Publication Date: 2026.03.24 MURATA MFG CO LTD

AI summary

An array accommodated in a housing includes multiple antenna elements. The antenna elements face an inside surface of the housing and are arrayed in a first direction at least one-dimensionally. A waveguide is coupled to the antenna elements of the array antenna and extends from the array antenna toward the inside surface of the housing. The waveguide has a housing-side end face facing the inside surface of the housing and an antenna-side end face facing the array antenna. A length from one end to an opposite end of the housing-side end face in the first direction is greater than a length from one end to an opposite end of the antenna-side end face in the first direction. An antenna device that can improve antenna gain without increasing the size of the antenna module is provided.