PCB Spiral Antenna Assembly Without a Separate Cavity

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Solution Overview

Problem

Conventional spiral antenna configurations require a separate cavity housing with absorber material to eliminate back lobe radiation, increasing the size of electromagnetic energy emission and reception systems.

Innovation Solution

The antenna system incorporates a substrate with a dual arm, Archimedean spiral antenna element and a conductive ground plane within a PCB stackup, utilizing conductive vias and resistive material to suppress cavity field modes, eliminating the need for a separate cavity and allowing unidirectional operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a separate cavity housing with absorber material is used to eliminate back lobe radiation, then radiation pattern control is improved, but the size of the electromagnetic energy emission and reception system increases

Engineering Contradiction:

Improveback lobe radiationVSAvoidsystem size

Core Design Contradiction:

Object-affected harmful factorsVSVolume of stationary object

Solution Approach 1:

The patent merges the cavity housing and absorber material functions into the PCB substrate itself. The substrate integrates the ground plane, antenna element support, and absorber material in a single structure, eliminating the need for separate cavity housing while maintaining radiation pattern control and reducing overall system size.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The PCB substrate serves multiple functions simultaneously: it provides mechanical support for the antenna element, acts as the ground plane, and incorporates absorber material to control radiation patterns. This multi-functionality eliminates the need for separate dedicated cavity structures while achieving the same radiation control objectives.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Object-affected harmful factors

If conventional spiral antenna configurations are used with separate cavity housing, then radiation control is achieved, but device complexity increases

Engineering Contradiction:

Improveback lobe radiationVSAvoidstructural complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent combines multiple structural elements (cavity housing, absorber material, ground plane, and antenna support) into a single integrated PCB substrate structure. This merging reduces the number of separate components and assembly steps, thereby reducing device complexity while maintaining radiation control functionality.

Inventive Principle:

Principle #5Merging (Combining)

3Volume of stationary object

If a compact antenna design is implemented, then integration is improved, but radiation pattern control may be compromised

Engineering Contradiction:

Improveantenna sizeVSAvoidradiation pattern control

Core Design Contradiction:

Volume of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies absorber material specifically at strategic locations within the PCB substrate where it is most effective for controlling back lobe radiation. This localized application of absorber material provides effective radiation pattern control in a compact design, avoiding the need for extensive cavity structures while maintaining performance.

Inventive Principle:

Principle #3Local quality

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

This configuration results in a compact, wideband, and high-performance antenna array with circular polarization and reduced mutual coupling, enabling efficient electromagnetic energy emission and reception across a wide frequency range without the need for a separate cavity, thus enhancing broadband gain and polarization stability.

Implementation Method 1

utilizing conductive vias and resistive material to suppress cavity field modes, eliminating the need for a separate cavity and allowing unidirectional operation

Methodology Applied

Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Implementation Method 2

configured to emit and receive electromagnetic energy

Methodology Applied

Scientific EffectElectromagnetic radiation:

Implementation Method 3

a conductive ground plane within a PCB stackup

Methodology Applied

Scientific EffectElectromagnetic shielding:

Implementation Method 4

produces circular polarization over a wide beamwidth and a wide bandwidth

Methodology Applied

Scientific EffectCircular polarization: Polarisation

Data Source

PatentUS11843166B2Antenna assemblies and antenna systems

Publication Date: 2023.12.12 BATTELLE MEMORIAL INST

AI summary

Antenna assemblies and antenna systems are described. According to one aspect, a printed circuit board antenna system includes a dielectric substrate comprising first and second surfaces that are opposite to one another, first electrically conductive material of an antenna element adjacent to the first surface of the dielectric substrate, wherein the antenna element is configured to emit electromagnetic energy, and second electrically conductive material of a ground plane adjacent to the second surface of the dielectric substrate, wherein the ground plane is aligned with the antenna element and configured to reflect some of the electromagnetic energy in a direction towards the antenna element.