Compact top-loaded, tunable fractal antenna systems for efficient ultrabroadband aircraft operation
First Claim
1. An antenna system, comprising:
- a conductive fractal member that extends from a first end to a second end and is configured to define an apex at said first end;
a top load having an aerodynamic shape and coupled to said second end; and
an aerodynamically-shaped dielectric blade arranged to surround said fractal member.
1 Assignment
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Accused Products
Abstract
Compact top-loaded, fractal monopole antenna system embodiments are provided for multi-band airborne operation over ultrabroadband ranges (e.g., 30 to 2000 MHz). These multi-band embodiments are self-contained, aerodynamic and compact (e.g., blade height less than 9.5 inches) and are power efficient with a low return loss (e.g., less than −7 dB). System embodiments include a set of impedance-matching circuits configured to substantially match an antenna impedance to a predetermined system impedance over a set of predetermined frequency bands. In an embodiment, at least one impedance-matching circuit includes a chain of selectable air-core inductors which are novelly arranged to improve radiation efficiency and prevent damage to support substrates. In an embodiment, a lowest-frequency one of the impedance-matching circuits is configured to process signals having a maximum wavelength λmax wherein a fractal member is configured with a length that does not exceed λmax/40. System embodiments are configured to respond to a variety of existing radio systems that send commands via different encoding formats.
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Citations
24 Claims
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1. An antenna system, comprising:
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a conductive fractal member that extends from a first end to a second end and is configured to define an apex at said first end; a top load having an aerodynamic shape and coupled to said second end; and an aerodynamically-shaped dielectric blade arranged to surround said fractal member. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An antenna system, comprising:
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a conductive member that extends from a first end to a second end; a top load coupled to add capacitance to said second end; and a set of impedance-matching circuits each configured to substantially match an antenna impedance at said first end to a predetermined system impedance over a respective one of a set of predetermined frequency bands; wherein one of said circuits includes a chain of selectable air-core coils to enhance said match over at least one of said frequency bands and further including a support substrate wherein at least two of said air-core coils are orthogonally arranged and supported by and spaced from said substrate. - View Dependent Claims (12, 13, 14, 15)
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16. An antenna system configured to respond to control commands, comprising:
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a conductive fractal member that extends from a first end to a second end; a top load coupled to said second end; a set of impedance-matching circuits each configured to substantially match a first end impedance to a predetermined system impedance over a respective one of a set of predetermined frequency bands; and a controller configured to couple any selected one of said circuits to said first end in response to said control commands. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24)
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Specification