Antenna Arrangement on Circuit Board with Slit Ground Plane

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Small size radio frequency modules with integrated cell-band antennas exhibit poor over-the-air performance within the 700 - 900 MHz band due to limitations in the size of the ground plane.

Innovation Solution

An antenna arrangement on a circuit board featuring a cell-band antenna, a ground plane with a slit antenna portion that extends the ground plane geometrically, and a mid portion connecting the cell-band and slit antennas, enhancing the ground plane's electrical extension and counterpoise, thereby improving performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the ground plane size is increased to improve over-the-air performance, then the antenna performance is improved, but the circuit board size increases

Engineering Contradiction:
Improveover-the-air performanceVSAvoidground plane area
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The ground plane is extended in the width direction by creating a slit antenna portion that protrudes from the main ground plane. This dimensional extension allows the ground plane to achieve an effective area larger than the circuit board footprint without increasing the overall board dimensions, thereby improving over-the-air performance while maintaining a compact form factor.

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

Solution Approach 2:

The slit antenna portion serves dual functions: it acts as both an extension of the ground plane to improve the cell-band antenna's over-the-air performance and simultaneously functions as a parasitic element for the slit antenna itself. This multi-functionality allows both the cell-band antenna and slit antenna to operate effectively within the same compact space.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If the ground plane is extended geometrically to improve performance, then the over-the-air performance is improved, but the available surface area on the circuit board is reduced

Engineering Contradiction:
Improveover-the-air performanceVSAvoidavailable surface area
Core Design Contradiction:
ReliabilityVSArea of moving object

Solution Approach 1:

Instead of extending the ground plane in the length direction which would consume valuable surface area, the invention extends it in the width direction by creating a slit that protrudes from the main ground plane. This allows the ground plane to achieve an effective electrical length greater than the physical board dimensions without sacrificing available surface area for other components.

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

Solution Approach 2:

The ground plane extension and the slit antenna are merged into a single structural feature. The slit antenna portion that protrudes from the ground plane serves both as an extension of the ground plane and as the radiating element for the slit antenna, eliminating the need for separate structures and optimizing space utilization.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3408890B1An antenna arrangement on a circuit board
Publication Date: 2022.03.09 SONY GROUP CORP
  • EP3408890B1 patent drawingFigure 1
  • EP3408890B1 patent drawingFigure 2
  • EP3408890B1 patent drawingFigure 3

AI summary

The present invention relates to an antenna arrangement on a circuit board (10) extending along a length direction,L, and a width direction, W, the width direction being orthogonal to the length direction. The antenna arrangement comprising: a cell-band antenna (20); a ground plane (30) associated with the cell-band antenna; and a slit antenna (40) arranged in a slit antenna portion (32) of the ground plane, the slit antenna comprising a slit (42) in the ground plane, the slit having in the width direction a slit extension extending from an in the length direction extending edge (34) of the ground plane, the slit extension being 50-95%of an in the width direction extending total width of the slit antenna portion.