Antenna Arm Switching for Multi-Frequency Bandwidth
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Solution Overview
Problem
Current antenna designs for terminal devices face inefficiencies due to switch losses when switching between resonance frequencies, and they often require increased space to accommodate multiple frequency bands.
Innovation Solution
An antenna apparatus with switches located at the end of antenna arms, allowing the arms to switch between grounded and floating states, thereby changing resonance frequencies without causing switch loss and maintaining compact size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a switch is disposed in the middle of an antenna circuit to control switching to different resonance frequencies, then the antenna bandwidth is increased, but the antenna efficiency is reduced due to switch loss
Solution Approach 1:
The switch is extracted from the middle of the antenna circuit and relocated to the end of the antenna arm. This extraction removes the switch from the high-voltage standing wave region in the middle of the antenna, placing it instead at a low-voltage point where switch loss has minimal impact on antenna efficiency, while still enabling frequency switching functionality
Solution Approach 2:
A grounding switch mechanism is introduced as an intermediary control element at the antenna end. This switch connects or disconnects the antenna arm to ground, enabling resonance frequency switching through a different mechanism that avoids the losses associated with traditional mid-circuit switching
2Loss of energy
If a common antenna without a switch is used to maintain antenna efficiency, then the antenna efficiency is preserved, but the space occupied by the antenna is increased
Solution Approach 1:
The antenna structure is made dynamically reconfigurable through the addition of a simple end-switch mechanism. This allows a single compact antenna structure to dynamically switch between different resonance frequencies by connecting or disconnecting to ground, eliminating the need for multiple static antenna elements that would occupy more space
Solution Approach 2:
The electrical parameters of the antenna (resonance frequency) are changed by modifying the boundary condition at the antenna end through switching to ground. This parameter change approach allows frequency switching without physically changing the antenna structure or adding space-consuming components
3Adaptability or versatility
If multiple antenna elements are used to support multi-frequency operations, then the frequency coverage is improved, but the device complexity and space occupation are increased
Solution Approach 1:
A single antenna element is designed to perform multiple functions by supporting multiple resonance frequencies through the end-grounding switch mechanism. This universal antenna design eliminates the need for multiple specialized antenna elements, reducing overall device complexity while maintaining multi-frequency operation capability
Data Source
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AI summary
The present invention discloses an antenna apparatus and a terminal device, which relate to the field of communications technologies. A switch disposed at an end of an antenna arm controls an antenna to switch to different resonance frequencies; therefore reduced antenna efficiency caused by switch loss is avoided and space occupied by the antenna is not increased. The antenna apparatus includes an antenna and a printed circuit board, where a feedpoint and a first grounding point are disposed on the printed circuit board; the antenna is connected to the feedpoint, and the antenna includes a first arm. The antenna apparatus further includes: a first switch, where an end of the first arm is connected to the first grounding point by using the first switch; when the first switch is closed, the end of the first arm is connected to the first grounding point; when the first switch is opened, the end of the first arm is floating. The terminal device includes the foregoing antenna apparatus, a radio frequency module connected to the antenna apparatus, and a switch control module connected to the antenna apparatus.