High-Efficiency Broadband Antenna With Adjustable Impedance Feed
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Solution Overview
Problem
Conventional crossed-field antennas (CFAs) do not achieve the high efficiency initially expected, despite their size advantages, in real-world testing.
Innovation Solution
A high-efficiency broadband antenna design featuring a D-plate and E-cylinder configuration with adjustable impedance feed networks, where approximately half of the transmitter input power is fed to each element, allowing for optimized electric and magnetic field propagation and surface wave radiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If conventional CFA designs with two driven elements and ground plane are used, then the antenna achieves compact size, but the radiation efficiency does not meet initial expectations
Solution Approach 1:
The antenna is divided into two separate driven elements (E-cylinder for electric field and H-rod for magnetic field) that are spatially separated and independently fed. This segmentation allows each element to be optimized for its specific field generation while maintaining compact overall size, resolving the contradiction between small size and efficient radiation.
Solution Approach 2:
A dual feed network with independent impedance matching circuits serves as an intermediary between the transmitter and the two driven elements. This intermediary system optimizes power distribution and impedance matching for each element separately, maximizing radiation efficiency while preserving the compact crossed-field structure.
2Device complexity
If conventional CFA designs are used, then the antenna structure is simplified, but the bandwidth and impedance consistency are insufficient for digital broadcasting
Solution Approach 1:
The feed network incorporates adjustable impedance matching circuits that can be dynamically tuned to maintain consistent input impedance across a wide frequency range. This dynamic adjustment capability enables the antenna to adapt to different operating conditions and achieve the bandwidth required for digital broadcasting while maintaining a relatively simple crossed-field structure.
Solution Approach 2:
The antenna design employs independent feed networks for each driven element with adjustable impedance parameters. By optimizing and adjusting these electrical parameters, the antenna achieves wide bandwidth and consistent impedance characteristics necessary for digital broadcasting, without significantly increasing structural complexity.
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 improved radiation efficiency and consistent input impedance, enabling efficient digital broadcasting with increased field strength and bandwidth, outperforming conventional short monopole antennas.
Implementation Method 1
one of which produces a high frequency electric field, and the other of which produces a high frequency magnetic field. The electric and magnetic field lines are arranged to cross, and thereby synthesize and propagate radio waves.
Implementation Method 2
a first antenna feed network, with adjustable impedance, configured to feed approximately half of the power from the transmitter input feed to the E-cylinder; and a second antenna feed network, with adjustable impedance, configured to feed approximately half of the power from the transmitter input feed to the D-plate.
Data Source
AI summary
A design for high-efficiency broadband antennas which includes a D-plate and an E-cylinder, electrically insulated from each other, the E-cylinder being above the D-plate, and both parts insulated from a ground plane. The E-cylinder and D-plate may be fed by distinct feed networks with adjustable impedance.