Dual-Band Antenna Unit Using Capacitive and Inductive Coupling
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Solution Overview
Problem
Existing antenna units designed for high frequency bands with wide bandwidth are not compatible with lower frequency bands without increasing the antenna size, making them incompatible with dual-band communication.
Innovation Solution
An antenna unit design featuring a first antenna conductor with expanding width, a second antenna conductor with a gap, and connection points via capacitors and inductors or zero-ohm resistors, allowing for efficient communication in both high and low frequency bands without significant size increase.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the antenna length is extended to become compatible with a lower frequency band, then the dual-band compatibility is achieved, but the size of the antenna unit increases
Solution Approach 1:
The antenna conductor is divided into multiple sections with different width characteristics. The first section has constant width for high frequency band operation, while the second section has expanding width to provide resonance paths for both high and low frequency bands without requiring overall length extension.
Solution Approach 2:
Different sections of the antenna conductor are given different width properties. The first section maintains constant width optimized for high frequency, while the second section expands in width to create appropriate electrical length for low frequency resonance, allowing each section to serve its specific frequency band function.
2Length of stationary object
If the antenna size is reduced for downsizing, then the compactness is improved, but the ability to communicate in lower frequency bands is lost
Solution Approach 1:
Instead of extending the antenna in one dimension (length) to achieve low frequency coverage, the invention uses width variation in the antenna conductor sections. The expanding width in the second section creates the necessary electrical length for low frequency resonance while maintaining compact overall dimensions.
Solution Approach 2:
The antenna conductor width is varied along its length - constant in the first section and expanding in the second section. This parameter change allows the antenna to present different electrical characteristics at different frequencies, enabling dual-band operation from a compact structure.
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
Enables effective communication in both high and low frequency bands with maintained antenna size, achieving favorable efficiency in both frequency ranges.
Implementation Method 1
a first connection part connecting the top end edge of the first antenna conductor and the second antenna conductor via a capacitor
Implementation Method 2
a second connection part connecting the top end edge of the first antenna conductor and the second antenna conductor via an inductor or a zero-ohm resistor
Data Source
AI summary
An antenna unit includes a feed point, a first antenna conductor extending from the feed point and having a width that expands as a distance from the feed point increases, a second antenna conductor facing a top end edge of the first antenna conductor with a gap formed therebetween, a first connection part connecting the top end edge of the first antenna conductor and the second antenna conductor via a capacitor, and a second connection part connecting the top end edge of the first antenna conductor and the second antenna conductor via an inductor or a zero-ohm resistor. A first connection point between the first connection part and the first antenna conductor is closer to a center of the top end edge of the first antenna conductor compared with a second connection point between the second connection part and the first antenna conductor.