Waveguide Antenna PCB with Transmission Line Band Gaps

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional waveguide structures for suppressing electromagnetic wave propagation in specific frequency bands are limited by large size and high manufacturing costs, particularly in designing small-size antennas for low-frequency operation, and require chip components that increase complexity and cost.

Innovation Solution

A waveguide structure comprising conductive planes and unit structures with transmission lines and conductive vias, where the transmission lines have different lengths and are arranged to create band gaps in frequency bands, allowing for reduced size and cost without using chip components, by controlling the length of the transmission lines and using dielectric materials to adjust effective dielectric constants.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional EBG structures use adequate capacitances and inductances by increasing areas of conductive patches or lengths of conductive vias, then electromagnetic wave suppression is achieved, but structure size increases making it difficult to reduce

Engineering Contradiction:
Improveelectromagnetic wave suppressionVSAvoidstructure size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent changes the physical parameters of the conductive patches (shape, size, arrangement) and transmission lines (length, configuration) to achieve the required capacitance and inductance values without increasing the overall structure size. By optimizing these parameters, the invention achieves effective electromagnetic wave suppression in a compact form factor.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If chip capacitors are mounted on the surface to increase capacitances, then capacitance requirements are met without increasing patch areas, but the number of parts increases leading to increased manufacturing cost

Engineering Contradiction:
ImprovecapacitanceVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent extracts the capacitor function from separate chip components and integrates it directly into the PCB structure through conductive patches and transmission lines. This integration eliminates the need for discrete chip capacitors, reducing part count and manufacturing complexity while maintaining the required capacitance values.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention merges the capacitor function with the existing PCB conductive elements (patches and transmission lines). By combining multiple functions (capacitance, inductance, electromagnetic wave suppression) into a single integrated structure, the patent eliminates the need for separate chip components and reduces manufacturing cost.

Inventive Principle:
Principle #5Merging (Combining)

3Volume of moving object

If small-size antennas are designed for low-frequency operation, then device size is reduced, but conventional waveguide structures become too large and expensive to implement

Engineering Contradiction:
Improveantenna sizeVSAvoidmanufacturing cost
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The patent changes the electrical parameters (capacitance, inductance) and physical parameters (transmission line length, conductive patch configuration) of the waveguide structure to achieve effective low-frequency operation in a compact size. By carefully controlling these parameters, the invention achieves low-frequency suppression without requiring large structure dimensions.

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 enables the design of small-size antennas operating in low-frequency ranges with reduced manufacturing costs and without the need for chip components, achieving effective suppression of electromagnetic wave propagation in specific frequency bands.

Implementation Method 1

Due to band gaps occurring in frequency bands in which the shunts serve as inductances in the EBG structure, it is possible to set band gaps by controlling serial-LC resonance frequencies of shunts

Methodology Applied
Scientific EffectElectromagnetic resonance: Resonance

Implementation Method 2

structures having band gaps in frequency dispersions are referred to as EBG structures, which are expectedly applied to filters for suppressing propagation of unwanted noise

Methodology Applied
Scientific EffectElectromagnetic band gap:

Implementation Method 3

using dielectric materials to adjust effective dielectric constants

Methodology Applied
Scientific EffectDielectric permittivity: Dielectric Permittivity

Data Source

PatentEP2221923B1Antenna and printed-circuit board using waveguide structure
Publication Date: 2018.07.18 NEC CORP
  • EP2221923B1 patent drawingFigure 1~2
  • EP2221923B1 patent drawingFigure 3~4
  • EP2221923B1 patent drawingFigure 5~6

AI summary

An antenna or a printed-circuit board is formed using a plurality of unit structures which are repetitively aligned in a one-dimensional manner or in a two-dimensional manner. The unit structure includes a conductive plane and a conductive patch which are disposed in parallel with each other, a power-supply unit applying a high frequency signal between the conductive plane and the conductive patch, and at least one shunt which is aligned in the conductive patch and which is constituted of a transmission line having an open end aligned in a plane above or below the conductive patch and a conductive via electrically connecting the transmission line to the conductive plane. Alternately, the transmission line is aligned in a plane above or below the conductive plane so that the transmission line is electrically connected to the conductive patch via the conductive via.