Planar Antenna Dynamic Frequency Switching for Handheld Devices
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Solution Overview
Problem
Conventional multi-frequency planar inverted-F antennas are too large, compromise transmission performance, and lack flexibility in switching between frequency bands, making them unsuitable for handheld devices with limited space and poor performance.
Innovation Solution
A planar antenna design utilizing a first radiator with an open terminal, short terminal, and feeding terminals, coupled via a transmission line and switch element, allowing resonance at two central frequencies without additional parasitic elements or branches, enabling flexible switching between frequency bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If additional parasitic antenna elements and/or branches are added to achieve multi-frequency operation, then the antenna can operate at multiple frequencies, but the size of the antenna increases
Solution Approach 1:
The patent applies dynamics by making the antenna structure adjustable through a switching mechanism. The radiator can be reconfigured between different states (with or without the extended branch) to operate at different frequencies. This dynamic reconfiguration allows multi-frequency operation without requiring all frequency-supporting elements to be present simultaneously, thus avoiding the area increase that would result from having all parasitic elements permanently installed.
2Adaptability or versatility
If the antenna size is increased to support multiple frequencies, then multi-frequency operation is achieved, but the handheld device becomes heavier and less slim
Solution Approach 1:
The antenna uses a switching mechanism that dynamically reconfigures the radiator structure. When operating at a lower frequency, the extended branch is connected; when operating at a higher frequency, the extended branch is disconnected. This dynamic adjustment means the physical antenna structure remains compact, and only the electrical configuration changes to support different frequencies, thereby avoiding the weight penalty of having permanent additional elements for all frequency bands.
3Ease of operation
If the antenna is not completely placed within the clearance area, then the design flexibility is improved, but the transmission performance is compromised due to external electronic interference
Solution Approach 1:
The dynamic reconfiguration capability allows the antenna to adapt its electrical characteristics to different operating conditions. By switching between different radiator configurations, the antenna can optimize its performance for each frequency band while maintaining a compact physical footprint that fits within the clearance area, thereby simultaneously achieving design flexibility and transmission performance.
4Adaptability or versatility
If conventional multi-frequency antenna switching technology is used, then frequency band switching is achieved, but the design complexity increases
Solution Approach 1:
The antenna is segmented into a basic radiator structure and an optional extended branch. The switching mechanism simply connects or disconnects the extended branch to the basic radiator, creating different frequency operating modes. This segmentation approach simplifies the switching design compared to conventional multi-frequency antennas that require complex switching networks, as only a single switch element is needed to toggle between two distinct frequency operating states.
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 reduced size, improved transmission performance, and flexible frequency switching, addressing the limitations of conventional multi-frequency antennas by allowing the antenna to operate within the handheld device's clearance area without external electronic interference.
Implementation Method 1
the first radiator comprises an open terminal 153, a short terminal 155, a first feeding terminal 157 and a second feeding terminal 159... When the switch element 19 is turned off, an RF signal outputted by the RF signal terminal 131 is fed from the first feeding terminal 157 to the first radiator 151 so that the first radiator 151 resonates at a first central frequency
Data Source
AI summary
A handheld device and a planar antenna thereof are provided. The planar antenna comprises a radiator with an open terminal, a short terminal, a first feeding terminal and a second feeding terminal. The short terminal is coupled to a ground terminal. The first feeding terminal is formed between the open terminal and the short terminal, and coupled to a radio frequency (RF) signal terminal. The second feeding terminal is formed between the open terminal and the first feeding terminal, and coupled to the first feeding terminal by a transmission line and a switch element. The radiator resonates at the first central frequency when the switch element is turned off, and resonates at the second central frequency when the switch element is turned on.