Slot Antenna Bandwidth via Capacitive Inductive Coupling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing slot antennas have limited bandwidth due to narrow ground planes and inadequate coupling mechanisms, leading to restricted frequency coverage and altered radiation behavior.

Innovation Solution

A slot antenna design featuring a rectangular electrode and ground plane with a capacitive and/or inductive coupling device placed within a slot that spans at least one wavelength, allowing for field coupling and achieving a broader bandwidth through orthogonal radiation modes and polarization control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If magnetic field coupling is used for feeding the slot antenna, then the antenna can be fed effectively, but the bandwidth is limited to a narrow band

Engineering Contradiction:
Improvefeeding effectivenessVSAvoidbandwidth
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent introduces a coupling device as an intermediary element between the feed line and the slot antenna. This coupling device includes a coupling electrode that capacitively couples to the slot, enabling effective feeding while avoiding the bandwidth limitations of direct magnetic field coupling. The coupling device acts as a mediator that transforms the feeding mechanism to achieve broader frequency coverage.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs parameter changes by adjusting the dimensions and configuration of the coupling device and slot structure. By optimizing the length, width, and position of the coupling electrode relative to the slot, the antenna achieves impedance matching across a wide frequency range, thereby increasing bandwidth while maintaining effective feeding.

Inventive Principle:
Principle #35Parameter changes

2Area of stationary object

If the ground plane is made narrow to reduce size, then the antenna structure is compact, but the bandwidth and radiation characteristics are degraded

Engineering Contradiction:
Improveground plane sizeVSAvoidbandwidth
Core Design Contradiction:
Area of stationary objectVSAdaptability or versatility

Solution Approach 1:

The patent segments the ground plane into a frame-like structure with distinct sides and spacing relationships. This segmentation allows the ground plane to maintain a compact overall footprint while creating multiple interaction zones with the slot and coupling device, thereby preserving bandwidth and radiation characteristics despite the reduced size.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent utilizes the spatial dimension by positioning the coupling device and slot in specific three-dimensional arrangements relative to the ground plane frame. By optimizing the vertical and lateral spacing, the antenna achieves enhanced coupling and broader bandwidth without increasing the ground plane's planar area, effectively using dimensional optimization to overcome the size-bandwidth trade-off.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Adaptability or versatility

If the slot length is increased to at least one wavelength to achieve broad bandwidth, then the frequency coverage is improved, but the antenna structure becomes larger

Engineering Contradiction:
Improvefrequency coverageVSAvoidantenna structure size
Core Design Contradiction:
Adaptability or versatilityVSLength of stationary object

Solution Approach 1:

The patent implements a nested configuration where the coupling device is positioned within or adjacent to the slot structure, and the slot is integrated within the ground plane frame. This nesting allows the electromagnetic fields to interact efficiently over a broad frequency range without requiring the overall antenna structure to be proportionally larger, as the components are space-efficiently arranged.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent creates dynamic electromagnetic coupling between the feed line, coupling device, and slot through the capacitive coupling mechanism. This dynamic coupling allows the antenna to adapt to a wide frequency range by utilizing resonant interactions that are not fixed to a single frequency, thereby achieving broad frequency coverage with a compact structure rather than requiring a physically large antenna for each frequency.

Inventive Principle:
Principle #15Dynamics

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 achieves a bandwidth of approximately 40% and supports ultra-wideband operation by utilizing field coupling, enabling efficient frequency coverage without negatively impacting antenna characteristics.

Implementation Method 1

The coupling device (34) has a capacitive and/or inductive coupling to the electrode (20) and/or the ground plane (10)

Methodology Applied
Scientific EffectCapacitive coupling: Capacitance

Implementation Method 2

The coupling device (34) has a capacitive and/or inductive coupling to the electrode (20) and/or the ground plane (10)

Methodology Applied
Scientific EffectInductive coupling: Electromagnetic Induction

Implementation Method 3

The coupling is based in particular on field coupling (capacitive and/or inductive feeding)

Methodology Applied
Scientific EffectField coupling: Electromagnetic Induction

Data Source

PatentEP3499640B1Slot antenna
Publication Date: 2021.06.30 HUBER ALOIS
  • EP3499640B1 patent drawingFigure 1~4
  • EP3499640B1 patent drawingFigure 5~9
  • EP3499640B1 patent drawingFigure 10~12

AI summary

The invention relates to a slotted antenna comprising at least one electrode, a ground plane, in particular surrounding the electrode, and at least one feed device, wherein the feed device is arranged in the region of the ground plane and/or the electrode, and wherein the feed device has a capacitive and/or inductive coupling device.