Multiband Dipole Antenna With Flexible Sleeve For Portable Radios
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Solution Overview
Problem
Portable hand-held radio communication devices have limited long-range communication capabilities due to low effective radiated power (ERP) from low-power RF amplifiers and inefficient antennas, such as the conventional 'rubber duck' or 'whip' antennas, which are small and lack effective counterpoises.
Innovation Solution
An antenna assembly comprising a low-band dipole antenna and a high-band dipole antenna with a flexible electrically conductive sleeve, an RF control device, and impedance matching networks, allowing for selective direction of RF energy across frequency bands, enhancing gain and efficiency by using a dielectric body to support the dipole elements and a secondary winding for impedance transformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If conventional shortened vertical monopole antennas (rubber duck/whip antennas) are used in portable hand-held radios, then the device portability and compact size are improved, but the antenna gain and efficiency deteriorate
Solution Approach 1:
The patent transitions from a conventional vertical monopole antenna to a dipole antenna configuration that extends in multiple dimensions. The dipole elements are arranged to provide effective radiating area in horizontal, vertical, and diagonal orientations, thereby achieving higher gain without increasing the handheld radio's compact form factor.
Solution Approach 2:
The patent integrates multiple dipole elements (first and second dipole antennas) within a single antenna assembly that attaches to the handheld radio. These nested dipole structures share common support infrastructure while providing independent radiating elements, achieving high gain without proportionally increasing overall size.
2Ease of manufacture
If conventional shortened vertical monopole antennas are used, then ease of manufacture and device simplicity are improved, but antenna efficiency and effective radiated power deteriorate
Solution Approach 1:
The patent changes the fundamental electrical parameters of the antenna system by implementing a dipole configuration with specific element lengths, spacing, and orientations. This parameter change transforms the antenna from an inefficient shortened monopole to an efficient resonant dipole structure, improving effective radiated power while maintaining manufacturability through standardized construction techniques.
3Length of moving object
If larger man-pack radios with conventional antennas are used, then communication range is improved, but device portability and user convenience deteriorate
Solution Approach 1:
The patent segments the antenna function into multiple independent dipole elements that can be selectively activated. This segmentation allows the system to achieve extended communication range through coordinated radiation from multiple elements while keeping the physical antenna assembly compact enough for handheld operation, thereby maintaining user convenience.
4Adaptability or versatility
If multiple frequency bands are supported, then adaptability and versatility are improved, but device complexity and antenna structure complexity increase
Solution Approach 1:
The patent designs dipole elements with dimensions and configurations that enable them to operate across multiple frequency bands. The first and second dipole antennas are structured to provide effective radiation for different band combinations, allowing a single antenna assembly to serve universal multi-band communication needs without requiring separate antennas for each frequency range.
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 antenna assembly provides improved gain and wider operating bands, enabling small portable radios to match or exceed the range performance of larger man-pack radios, with the flexible electrically conductive sleeves and impedance matching networks minimizing power loss and maximizing communication range.
Implementation Method 1
The flexible electrically conductive sleeve surrounds a transmission line that extends from the low-band dipole feed to the high-band dipole feed
Implementation Method 2
A secondary winding of the second impedance transformer is connected to the first and second low-band dipole elements
Data Source
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AI summary
Antenna assembly (100) to be worn by a user includes a low-band dipole antenna (310) and at least one high band dipole antenna (312). The high-band dipole antenna is comprised of a high-band dipole feed (102) interposed at a location along a length of a low-band dipole element (105,110). The high-band dipole feed divides the first low-band dipole element into a first high-band dipole element (128) and a second high-band dipole element (130). One of the high-band dipole elements (130) is formed as a flexible electrically conductive sleeve. An RF control device (308) is provided for selectively directing RF energy in a high-band to the high-band dipole feed (102), and for selectively directing RF energy in a low-band to the low-band dipole feed (202).