Triadic Koch Curve |
Two antenna forms based on the Triadic Koch Curve will be analyzed. The first a mono/dipole form and the second
a loop form. The object of this
study is to observe the resonant behavior of an antenna structure that is built up incrementally in sections of
four wires. These cyclic elements (much in the sense of array or yagi elements) have an unique shape that is a
fundamental pattern for the entire structure. For the Triadic Koch Curve, these 4 wires give the appearance of
a triangular jog in a vertical line. The
antenna shown consists of 64 straight wires, each 1.1 meter long; total height is 30 meters. This antenna lies
entirely within the YZ plane. The basic curve of the greater structure can be found in the first four wires' shape
(cyclic element shown in small inset).SWR frequency sweeps were performed on the structure each time a cyclic element was added. The number of resonances were noted and then another cyclic element added. For the structure shown here, there are 16 cyclic elements. In the study of SWR for element 1, there was only 1 resonance between 5 and 50 MHz. When cyclic element 2 (wires 4 through 8) was added, the number of resonances between 5 and 50 MHz increased to 3. With the addition of each additional cyclic element, additional resonances were added to the structure. |
Fractal ResonancesMore kinks means more resonances, especially for the Triadic Koch. Through the progressions of constructing this final form, each iteration presented more resonances to a constant frequency sweep of the structure.
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Same data
viewed from a Hi Z perspective of 200 Ohms |
Folded Koch Curve to present a LoopHere, the curve from above is folded back on itself and fed at the sharp apex in the lower left corner (the
junction of wire 1 and wire 64). There are no shorts in the structure as might be suggested by the proximity of
points illustrated below. The first difference between this form and the standard form is found in the lower count
of resonances for constant wire length. One such site I evaluated is in the pinch that just precedes the ballooning of the structure (wire 8 end 2 to
wire 57 end 1). The intent was to see if the minor loop developed to the left of the drive would serve as a shunting
stub to the major loop to the right. |
Wire 1/64 Fed (as shown above)
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Wire 15 Fed (broad apex with wide symmetry)
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Shunt Fed
This too exhibits the pairing of resonances such as the sixth and seventh nulls in this display. The Object of this study, to observe tuned shunts, is lost in the resonances as it is. It would be tempting to embrace the twining of resonances at nulls 6 and 7, but these twinnings are too common otherwise. |