Broadband monopole/ dipole antenna with parallel inductor-resistor load circuits and matching networks
First Claim
1. A broadband antenna configured to operate in a substantially wide frequency band and to provide omnidirectional radiation in azimuth, said broadband antenna comprising:
- at least one substantially straight antenna arm;
at least one load circuit including a combination of passive circuit elements positioned in a predetermined location along said at least one substantially straight antenna arm, wherein values for selected passive circuit elements and for the predetermined location of said at least one load circuit is optimized via a genetic algorithm; and
a matching network provided at the base of said at least one substantially straight antenna arm for connecting said broadband antenna to a transmission line, said matching network comprising a transmission line transformer in parallel with an inductor.
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Accused Products
Abstract
A broadband loaded antenna and matching network with related methods for design optimization are disclosed. The loaded antenna structures may preferably be either monopole or dipole antennas, but the particular methods and techniques presented herein may be applied to additional antenna configurations. The load circuits positioned along an antenna may comprise parallel inductor-resistor configurations or other combinations of passive circuit elements. A matching network for connecting an antenna to a transmission line or other medium preferably includes at least a transmission line transformer and a parallel inductor. Various optimization techniques are presented to optimize the design of such broadband monopole antennas. These techniques include implementation of simple genetic algorithms (GAs) or micro-GAs. Component modeling for selected components may be effected through either lumped element representation or curved wire representation. Measured results are presented to ensure that certain design criteria are met, including low voltage standing wave ratio (VSWR) and high gain over a desired frequency band.
22 Citations
49 Claims
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1. A broadband antenna configured to operate in a substantially wide frequency band and to provide omnidirectional radiation in azimuth, said broadband antenna comprising:
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at least one substantially straight antenna arm;
at least one load circuit including a combination of passive circuit elements positioned in a predetermined location along said at least one substantially straight antenna arm, wherein values for selected passive circuit elements and for the predetermined location of said at least one load circuit is optimized via a genetic algorithm; and
a matching network provided at the base of said at least one substantially straight antenna arm for connecting said broadband antenna to a transmission line, said matching network comprising a transmission line transformer in parallel with an inductor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of designing a loaded broadband antenna configuration with circuit values and locations for load circuits and a matching network positioned along such an antenna, said method utilizing a micro-GA technique and comprising the followings steps:
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(i) establishing a set of design criteria for selected circuit values, load positions and antenna performance criteria;
(ii) creating an initial antenna population with member size N;
(iii) evaluating an objective function at least once for each member in the antenna population;
(iv) forming a selected number of successive generations of antennas, wherein said third step of evaluating an objective function is repeated for each generated antenna, and wherein said generating step is repeated for the selected number of times;
(v) choosing an elite generation of antennas by selecting the best member of the generated antenna population, said best member defined by selected results of said evaluating step, as well as by randomly selecting M other members to be included in the next generation of antennas; and
(vi) determining if the established set of design criteria is met and subsequently either upon determining that the set of design criteria is met then ending said method, or upon determining that the set of design criteria is not met then repeating said method beginning at step (iii). - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A matching network for connecting an antenna to a transmission line, whereby the provision of such a matching network increases the operating bandwidth of the antenna, said matching network comprising:
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a transmission line transformer capable of operating in a frequency range from about one MHz to about one GHz; and
a passive circuit element provided in parallel with said transmission line transformer;
wherein said matching network is configured without the inclusion of additional passive circuit elements. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30)
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31. A loaded broadband antenna configured to operate in a generally wide frequency band and to provide substantially omnidirectional radiation in azimuth, said loaded broadband antenna comprising:
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a first substantially straight antenna arm portion defined by first and second respective ends thereof;
a load circuit connected to a selected end of said first antenna arm portion, said load circuit comprising a resistor and a first inductor provided in parallel;
a second substantially straight antenna arm portion defined by a first end connected to said load circuit and a second end; and
a matching network configured to interface the second end of said second antenna arm portion to a transmission line and to match the impedance of the loaded broadband antenna to the impedance of the transmission line, wherein said matching network comprises a transmission line transformer provided in parallel with a second inductor. - View Dependent Claims (32, 33, 34, 35, 36, 37)
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38. A loaded broadband antenna configured to operate in a generally wide frequency band and to provide substantially omnidirectional radiation in azimuth, said loaded broadband antenna comprising:
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at least one substantially straight antenna arm, wherein said antenna arm is configured to provide a plurality of load circuits integrated at selected locations along said antenna arm, said antenna arm defined by first and second respective ends thereof, the first end being connected to a transmission line and the second end extending from the transmission line;
first, second and third load circuits provided at selected locations along said at least one substantially straight antenna arm, wherein selected of said load circuits comprise a resistor and a load inductor provided in parallel;
a matching network configured to interface the first end of said antenna arm to a transmission line and to match the impedance of the loaded broadband antenna to the impedance of the transmission line, wherein said matching network comprises a transmission line transformer provided in parallel with a matching network inductor. - View Dependent Claims (39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49)
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Specification