UHF Quad-Trapezoid-Loop Antenna analyzed using 4nec2, formed by adding outer parts of Chireix 2-Square to an Hourglass-Loop. All dimensions determined using nikiml's Optimization Scripts.
Three versions analyzed: Quad-Trap (NO Reflector), Quad-Trap (11 RR) and Quad-Trap (15 RR).
================================================= a) Quad-Trapezoid-Loop (NO Refl): AWG10 Elements.
UHF Raw Gain = 6.7 to 8.4 to 7.8 dBi and SWR (300-ohms) under 1.8. Note Very Wide 70-60 degree Beamwidth.
================================================= b) Quad-Trapezoid-Loop + 11 Reflector Rods: AWG10 Elements and 1/4-in O.D. Reflector Rods.
UHF Raw Gain = 9.7 to 11.6 dBi, F/B & F/R Ratio Min. = 19.9 dB and SWR (300-ohms) Under 1.9. BEAMWIDTH is 60 to 50 degrees across UHF Band with a VERY DEEP Notch directly to the Rear.
================================================= c) Quad-Trapezoid-Loop + 15 Reflector Rods: AWG10 Elements and 1/4-in O.D. Reflector Rods.
UHF Raw Gain = 10.1 to 11.8 dBi, F/B & F/R Ratio Min =19.2 dB and SWR (300-ohms) under 2.7. Note VERY WIDE BEAMWIDTH, 60-degrees ALL across the UHF Band and the VERY DEEP Notch directly to the Rear.
EDIT (7Mar2015): Added 11RR version.
Date(s): 11 Jul 2014. Album by holl_ands. 1 - 51 of 51 Total. 13443 Visits.
enlarge 76KB, 803x1024 1 UHF Quad-Trapezoid-Loop 3D View
enlarge 198KB, 681x1024 2 UHF Quad-Trapezoid-Loop (NO Refl) Front View [1 large square = 2.5 inches]
Balun (4:1 300-to-75-ohm Transformer) connects in place of Red Circle in Middle.
Note 1/4-in GAP at Top and Bottom.
enlarge 101KB, 479x1024 3 UHF Quad-Trapezoid-Loop (NO Refl) Top View [1 large square = 2.5 inches]
enlarge 160KB, 1024x675 4 UHF Quad-Trapezoid-Loop (NO Refl) UHF Raw Gain = 6.7 to 8.4 to 7.8 dBi
enlarge 186KB, 1024x675 5 UHF Quad-Trapezoid-Loop (NO Refl) UHF SWR (300-ohms) under 1.8
enlarge 221KB, 1024x675 6 UHF Quad-Trapezoid-Loop (NO Refl) UHF Impedance
enlarge 317KB, 1024x1024 7 UHF Quad-Trapezoid-Loop (NO Refl) Azimuthal Pattern at 470 MHz
enlarge 316KB, 1024x1024 8 UHF Quad-Trapezoid-Loop (NO Refl) Azimuthal Pattern at 530 MHz
enlarge 316KB, 1024x1024 9 UHF Quad-Trapezoid-Loop (NO Refl) Azimuthal Pattern at 590 MHz
enlarge 311KB, 1024x1024 10 UHF Quad-Trapezoid-Loop (NO Refl) Azimuthal Pattern at 650 MHz
enlarge 311KB, 1024x1024 11 UHF Quad-Trapezoid-Loop (NO Refl) Azimuthal Pattern at 698 MHz
enlarge 308KB, 1024x1024 12 UHF Quad-Trapezoid-Loop (NO Refl) Azimuthal Pattern at 758 MHz
enlarge 284KB, 1024x1024 13 UHF Quad-Trapezoid-Loop (NO Refl) Azimuthal Pattern at 806 MHz
enlarge 27KB, 791x1024 14 UHF Quad-Trapezoid-Loop (NO Refl) 4nec2 File
enlarge 87KB, 326x1024 15 UHF Quad-Trapezoid-Loop (NO Refl) Side View [1 large square = 2.5 inches]
enlarge 103KB, 843x1024 16 UHF Quad-Trapezoid-Loop + 11RR 3D View
enlarge 278KB, 1017x1024 17 UHF Quad-Trapezoid-Loop + 11RR Front View [1 large square = 2.5 inches]
enlarge 121KB, 507x1024 18 UHF Quad-Trapezoid-Loop + 11RR Top View [1 large square = 2.5 inches]
enlarge 168KB, 1024x741 19 UHF Quad-Trapezoid-Loop + 11RR UHF Raw Gain = 9.7 to 11.6 dBi UHF F/B & F/R Ratio Min. = 19.9 dB
enlarge 123KB, 512x1024 30 UHF Quad-Trapezoid-Loop + 11RR Side View [1 large square = 2.5 inches]
enlarge 160KB, 1024x741 31 UHF Quad-Trapezoid-Loop + 11RR Hi-VHF Raw Gain TO REAR = 5.0 to 5.1 dBi Hi-VHF F/B & F/R Ratio = 3.8 to 14.2 dB MORE GAIN TO REAR
enlarge 156KB, 1024x741 32 UHF Quad-Trapezoid-Loop + 11RR UHF Raw Gain FORWARD = 1.3 to -10.0 dBi
enlarge 192KB, 1024x741 33 UHF Quad-Trapezoid-Loop + 11RR Hi-VHF SWR (300-ohms) = 167 to 9.4 is Excessive
enlarge 304KB, 1024x1024 34 UHF Quad-Trapezoid-Loop + 11RR Azimuthal Pattern at 174 MHz More Gain to REAR
enlarge 302KB, 1024x1024 35 UHF Quad-Trapezoid-Loop + 11RR Azimuthal Pattern at 198 MHz More Gain to REAR
enlarge 300KB, 1024x1024 36 UHF Quad-Trapezoid-Loop + 11RR Azimuthal Pattern at 216 MHz More Gain to REAR
enlarge 147KB, 828x1024 37 UHF Quad-Trapezoid-Loop + 15RR 3D View
enlarge 266KB, 843x1024 38 UHF Quad-Trapezoid-Loop + 15RR Front View [1 large square = 2.5 inches]
enlarge 123KB, 468x1024 39 UHF Quad-Trapezoid-Loop + 15RR Top View [1 large square = 2.5 inches]
enlarge 179KB, 1024x675 40 UHF Quad-Trapezoid-Loop + 15RR UHF Raw Gain = 10.1 to 11.8 dBi UHF F/B & F/R Ratio Minimum = 19.2 dB