Multi-band Antenna with Capacitor and Short-circuiting Paths
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Solution Overview
Problem
Conventional antennas fail to simultaneously satisfy the LTE/GSM/UMTS eight bands standards due to narrow bandwidths and large dimensions, as they rely on two-resonant path designs that are not compatible with high-speed wireless communication requirements.
Innovation Solution
A communication device with a built-in antenna featuring a radiator, feed conductor, capacitor unit, and short-circuiting unit, where the capacitor unit and two short-circuiting paths control impedance matching to increase bandwidth and reduce dimensions, covering LTE700/GSM850/900 and GSM1800/1900/UMTS/LTE2300/2500 bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional two-resonant path antenna design is used, then dual-band operation is achieved, but bandwidth is narrow and dimensions are large
Solution Approach 1:
The antenna is divided into multiple functional segments: a radiator element for radiation, a feed conductor with capacitor unit for impedance control, and a short-circuiting unit with first and second short-circuiting paths for bandwidth enhancement. Each segment performs a specific function to collectively achieve wideband dual-band operation, resolving the contradiction between dual-band capability and narrow bandwidth.
Solution Approach 2:
The patent introduces a third dimension by adding vertical short-circuiting paths between different layers of the antenna structure. The first short-circuiting path connects the radiator to the ground in the first layer, while the second short-circuiting path extends vertically to create additional resonance modes. This dimensional expansion enables simultaneous support for multiple frequency bands with wide bandwidth.
2Device complexity
If conventional antenna design is used, then simple structure is maintained, but it cannot satisfy LTE/GSM/UMTS eight bands standards simultaneously
Solution Approach 1:
The antenna structure is designed as a universal multi-functional system where the radiator element, feed conductor with capacitor, and short-circuiting unit work together to support eight different frequency bands across LTE, GSM, and UMTS standards. The capacitor unit and short-circuiting paths are configured to provide impedance matching and resonance control that enables simultaneous operation across all eight bands, achieving multi-functionality without requiring separate antennas for each band.
3Device complexity
If direct-feed design is used, then simple feeding is achieved, but high inductance of input impedance reduces impedance matching
Solution Approach 1:
A capacitor unit is introduced as an intermediary element between the feed conductor and the radiator element. This capacitor compensates for the high inductance introduced by the direct-feed design, achieving impedance matching. The capacitor acts as a mediator that cancels the inductive reactance, allowing the simple direct-feed structure to achieve reliable impedance matching across the operating bands.
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 enables the antenna to meet LTE/GSM/UMTS eight bands transmission requirements, allowing for slim portable communication devices with improved impedance matching and increased operation bandwidths.
Implementation Method 1
The capacitor unit decreases the high inductance of the input impedance generated by the direct-feed design of the antenna to improve impedance matching of the first band
Implementation Method 2
The short-circuiting unit includes a first short-circuiting path and a second short-circuiting path to control impedance matching, to increase bandwidths
Implementation Method 3
The first and second short-circuiting path lengths are longer than 0.05 times that of a wavelength of a lowest frequency of the first band to improve impedance matching of the first band, and to generate a new resonant mode at the second band, and to increase bandwidth of the first band and the second band
Data Source
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AI summary
A communication device is provided, including a ground element, a substrate and an antenna. The substrate is adjacent to the ground element. The antenna provides a first band and a second band, and the antenna is disposed on the substrate. The antenna includes a radiator, a feed conductor, a capacitor unit and a short-circuiting unit. An end of the feed conductor is connected to a signal source, and another end of the feed conductor is electrically connected to the radiator. The capacitor unit is disposed on the feed conductor. The short-circuiting unit includes a first short-circuiting path and a second short-circuiting path, wherein the first and a second short-circuiting paths electrically connect the radiator to the ground element, the first short-circuiting path has a first path length, the second short-circuiting path has a second path length, and the first and second path lengths are longer than 0.05 times that of a wavelength of a lowest frequency of the first band.