Balanced Planar mmWave Antenna with Balun and Parasitic Element
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Solution Overview
Problem
Conventional antennas for millimeter wave frequencies face challenges in supporting multiple frequencies, inducing strong surface waves in device chassis, and achieving broad radiation patterns, which affects performance and array applications.
Innovation Solution
A balanced planar antenna with a balun structure and a parasitic element is designed to support 5G mmWave frequencies, featuring a ground plane, antenna elements, and a feed line on a substrate, with a balun that electrically balances the antenna and a parasitic element adding a second resonant frequency, reducing surface currents and enhancing bandwidth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional antennas are used at mmWave frequencies, then the antenna can operate at a single frequency, but it cannot support multiple mmWave frequencies simultaneously
Solution Approach 1:
The patent implements a multimode antenna design where a single antenna structure supports multiple mmWave frequencies (28 GHz and 39 GHz bands). The antenna elements are designed with specific dimensions and configurations that enable resonance at multiple frequencies simultaneously, allowing the antenna to serve universal communication functions across different 5G frequency bands without requiring separate antennas for each frequency
2Object-generated harmful factors
If conventional antennas are used at mmWave frequencies, then the antenna structure is simple, but it induces strong surface waves in the chassis that distort radiation patterns
Solution Approach 1:
The patent extracts and removes the problematic ground plane from the antenna structure. By eliminating the traditional ground plane that acts as a large reflective surface, the design prevents the generation of strong surface waves in the chassis. The antenna achieves proper balancing and stable radiation patterns through alternative grounding techniques and balanced feed structures, thereby extracting the harmful ground plane function while maintaining antenna performance
3Shape
If conventional antennas are used at mmWave frequencies, then the antenna elements can be simple, but achieving broad radiation patterns with low coupling is difficult
Solution Approach 1:
The patent employs asymmetric antenna element configurations and spacing arrangements to achieve broad radiation patterns. The antenna elements are positioned and dimensioned asymmetrically relative to each other and to the device boundaries, which helps control coupling between elements and shapes the radiation pattern to provide broad coverage. This asymmetric design allows the antenna to achieve desirable radiation characteristics without requiring complex additional structures
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 results in low surface current induction, desirable radiation patterns, and support for multiple mmWave frequencies, making it suitable for array applications and reducing side lobes, thus improving operational performance in mobile devices.
Implementation Method 1
a balun disposed on the substrate and connecting the first antenna element to the ground plane, wherein the balun is configured to electrically balance the antenna
Implementation Method 2
an antenna that has one or more resonant frequencies in the millimeter (mm) wave range
Implementation Method 3
The antenna includes a single antenna element 16 disposed on the substrate 14 adjacent an edge of the ground plane 12
Implementation Method 4
A parasitic element may be added for dual band operation
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A balanced planar antenna having at least one mmWave resonant frequency includes a ground plane, first and second antenna elements, an arm that connects the second antenna element to the ground plane, a feed line connected to the first antenna element and for feeding a radio frequency signal to the first antenna element, and a balun that connects the first antenna element to the ground plane. The ground plane, first antenna element, second antenna element, arm, feed line and balun each are disposed on a substrate and are coplanar.