Embedded Bowtie Antenna in Armor Panel
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Solution Overview
Problem
Conventional antennas on armored vehicles are vulnerable to damage and have non-optimal performance due to close spacing with conductive surfaces, limiting bandwidth and gain, and resulting in poor voltage standing wave ratios (VSWR).
Innovation Solution
A thin embedded antenna system using a driven bowtie dipole inside an armor plate with two parasitically-driven bowtie dipoles and an air gap, along with resistors to optimize performance, providing improved gain and VSWR across a wide bandwidth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a driven bowtie dipole is placed inside an armor plate with a parasitic bowtie dipole on the outside, then the antenna achieves a thin embedded structure without apertures in the armor, but the close spacing between the dipole and conductive surface creates a ground plane that limits bandwidth and gain
Solution Approach 1:
A dielectric layer is introduced between the driven bowtie dipole and the interior conductive surface of the armor plate. This dielectric intermediary increases the effective electrical spacing between the radiating element and the ground plane, thereby improving bandwidth and gain performance while maintaining the thin physical structure of the embedded antenna
Solution Approach 2:
The electrical properties of the medium between the dipole and conductive surface are modified by introducing a dielectric material with specific permittivity. This parameter change allows the antenna to achieve better impedance matching and radiation characteristics despite the constrained physical spacing within the thin armor plate
2Device complexity
If conventional whip antennas are used on armored vehicles, then the antenna structure is simple and easy to implement, but the antennas are susceptible to damage from explosive attacks and ballistic penetration
Solution Approach 1:
The bowtie dipole antenna elements are nested within cavities or recesses in the armor plate, with the driven dipole positioned inside the armor plate and the parasitic dipole on the exterior surface. This nested configuration protects the antenna elements from direct exposure to ballistic and explosive threats while maintaining antenna functionality
Solution Approach 2:
The antenna structure is merged with the armor plate itself, integrating the radiating elements into the protective structure. The armor plate serves dual purposes as both protective shielding and antenna support structure, eliminating the need for separate vulnerable whip antennas
3Reliability
If the ground plane is spaced at least a quarter wavelength away from the driven bowtie dipole, then optimal bandwidth and gain are achieved, but the armor panel thickness does not provide sufficient spacing
Solution Approach 1:
A dielectric layer is positioned between the driven bowtie dipole and the interior conductive surface to provide additional electrical spacing. This intermediary layer effectively increases the distance between the radiating element and the ground plane without increasing the physical thickness of the armor panel, thereby achieving better bandwidth and gain performance
Solution Approach 2:
The spacing problem is solved by transitioning from purely physical spacing to electrical spacing through the introduction of a dielectric material. The dielectric layer adds electrical length to the spacing without adding proportional physical thickness, allowing the antenna to achieve quarter-wavelength spacing effects in a thinner structure
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 achieves enhanced forward gain, reduced VSWR, and increased efficiency, enabling the antenna to operate effectively across 225-450 MHz with a gain of at least −1 dBi and VSWR less than 3:1, while maintaining ballistic penetration resistance and operational reliability.
Implementation Method 1
Each of the parasitic bowtie dipoles is parasitically coupled to the driven bowtie dipole through near-field coupling
Data Source
AI summary
A high powered armor panel having the wideband embedded antenna for operation in severe environmental conditions. The armor panel comprises a driven bowtie dipole electrically coupled to at least one driven resistor, a parasitic bowtie dipole electrically coupled to at least one parasitic resistor, a composite structure which has the driven bowtie dipole and the parasitic bowtie dipole embedded therein, a heat sink supported on a first side of the composite structure for dissipating heat, and an armor layer supported on an opposite second first side of the composite structure. The heat sink supports the at least one driven resistor electrically coupled to the driven bowtie dipole and the at least one parasitic resistor electrically coupled to the parasitic bowtie dipole.