UHF 15-Element "Double-Quad" Yagi (aka "Stacked Yagis with common Bi-Quad Driver") analyzed using 4nec2.
Similar to "DOPPELQUAD" 2-m & 70-cm narrowband Radio Amateur antennas from BAZ Spezialantennen: http://www.spezialantennen.eu/amateurfunk/doppelquad-antenne/index.php http://www.amateur-radio-antenna.com/amateurradio-antenna/double-quad-antenna/index.php http://translate.google.com/translate?sl=auto&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.spezialantennen.eu%2Famateurfunk%2Fdoppelquad-antenne%2Findex.php&act=url
I used nikiml's Python Scripts to Optimize a 4nec2 File constructed with fol. Constraints: 1) Active Element is a Bi-Quad with upper/lower sets of Yagi Directors (6 per set) plus four Reflectors with the same X-Coordinate located BETWEEN the plane of the Directors. [If allowed to extend BEYOND the plane, F/B, F/R & Gain may improve...analysis TBD.] 2) All Element locations symmetric above/below X-Y plane, 3) Inner Reflector's Z-Coordinate is 5% to 50% of upper/lower Z-Coordinate of Directors. 4) Outer Reflector's Z-Coordinate is 50% to 95% of upper/lower Z-Coordinate of Directors. 5) Range for Plane of Directors was very wide: between +/- 4-inches and +/- 24-inches from Center.
Optimized dimensions are found in the 4nec2 File.
Date(s): 23 Jun 2013. Album by holl_ands. 1 - 16 of 16 Total. 6486 Visits.
enlarge 96KB, 1024x816 1 UHF 15-El Double-Quad Yagi 3D View
enlarge 211KB, 789x1024 2 UHF 15-El Double-Quad Yagi Front View [1 large square = 2.5 inches]
enlarge 188KB, 1152x638 3 UHF 15-El Double-Quad Yagi Top View [1 large square = 2.5 inches]
enlarge 176KB, 1152x678 4 UHF 15-El Double-Quad Yagi UHF Raw Gain 10.6 to 13.6 dBi F/B & F/R Minimum = 17.1 dB