Multiband Antenna Design for Wireless Devices
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Solution Overview
Problem
Existing wireless communication devices face challenges in achieving multiband compatibility without increasing size and weight, as tunable antennas often create harmful harmonics and require additional hardware to switch between frequency bands.
Innovation Solution
The use of a combination of quarter-wavelength and half-wavelength antennas, including a planar inverted F-type antenna and loop antennas, capacitively coupled to a printed circuit board, allows for simultaneous communication across multiple frequency bands without the need for switching, maintaining energy levels within regulatory limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If tunable antennas are used to achieve multiband compatibility, then frequency range is improved, but device size and weight increase
Solution Approach 1:
The patent combines multiple fixed-frequency antennas (quarter-wavelength and half-wavelength antennas) into a single integrated antenna system. These antennas are coupled together through a feed point on the PCB, allowing the device to operate across multiple frequency bands simultaneously without requiring separate tunable antenna mechanisms, thereby avoiding the weight penalty of mechanical tuning components.
Solution Approach 2:
The antenna system is designed with multi-functionality to handle multiple frequency bands (including LTE, AMPS, GSM, DCS, PCS, and UMTS) using a fixed structural configuration. The combination of quarter-wavelength and half-wavelength antennas provides universal coverage across different network generations and geographic regions without requiring the device to carry adjustable or reconfigurable antenna components.
2Adaptability or versatility
If tunable antennas are used to achieve multiband compatibility, then frequency range is improved, but device complexity increases
Solution Approach 1:
Multiple antenna functions are merged into a single integrated structure where quarter-wavelength and half-wavelength antennas are coupled through a common feed point. This eliminates the need for complex switching mechanisms, tunable elements, or multiple independent antenna systems, thereby reducing overall device complexity while maintaining multiband capability.
Solution Approach 2:
Instead of using a single tunable antenna that requires complex adjustment mechanisms to cover multiple bands, the patent inverts the approach by using multiple fixed-frequency antennas with simple geometric structures. This inversion eliminates the need for tuning mechanisms and reduces system complexity.
3Volume of moving object
If antenna size is minimized, then device profile is improved, but radiation efficiency decreases
Solution Approach 1:
The patent merges quarter-wavelength and half-wavelength antenna structures in a compact configuration coupled at a feed point. This combination allows the antennas to resonate at multiple frequencies while maintaining efficient radiation patterns, achieving good radiation efficiency without requiring large individual antenna elements.
Solution Approach 2:
The antenna system utilizes planar configurations printed on the PCB, transitioning from three-dimensional bulky structures to two-dimensional flat layouts. This dimensional change reduces the overall volume and profile of the antenna system while maintaining effective radiating surfaces through optimized trace patterns and ground plane designs.
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
This solution enables wireless devices to communicate effectively across various frequency bands, including LTE, AMPS, GSM, DCS, PCS, and UMTS, without the use of switches, ensuring compatibility and compliance with FCC regulations while minimizing device size and weight.
Implementation Method 1
The first antenna is capacitively coupled to the PCB at a feed point
Implementation Method 2
The second antenna is coupled to the first antenna at the feed point
Implementation Method 3
The third antenna is a half-wavelength antenna receiving the second signals and third signals
Implementation Method 4
one of a filter and a shunt LC circuit coupled between the third antenna and the further ground point filtering the second signals and communicating the third signals with the wireless transceiver
Data Source
AI summary
A device for wireless communication including a wireless transceiver, a printed circuit board (PCB) coupled to the wireless transceiver, a first antenna and a second antenna. The first antenna is coupled to the PCB at a feed point and grounded at a ground point. The first antenna is a quarter-wavelength antenna communicating signals with the wireless transceiver at a first frequency band. The second antenna is coupled to the first antenna at the feed point and grounded at a further ground point. The second antenna is a half-wavelength antenna communicating signals with the wireless transceiver at a second frequency band.