Com3 2Q1617 Antenna Design Key design requirements 8/1/2018 Com3 2Q1617 Antenna Design Key design requirements Undertake the theoretical computations of shapes and geometries with clear preferably same scale illustrations Provide the wire geometries input to NEC for all configurations in Excel table form; make sure intersections terminates exactly You may have to configure curves and sheets with short sections of linear wire, compute the metric diameter of the 8AWG wire A wire section should have at least 5 segments Package report concisely, e.g. side by side comparisons of 3D and 2D plots, with 3 D antenna geometry, indicate gain F/B ratio and beam width for each pattern rather than one pattern per page In addition to the profiles, make sure to include the wire diagrams and orient all diagrams so that it is clearly perceived by the reader, if necessary use more than one illustration for a particular configuration Simulation is easy, the difficult part is the math of steps 1 and 2. Remember garbage in garbage out. There are also corrupted versions of NEC out there. Hard copy final report, see separate PDF file for details Soft copy to include all input data for the simulator, a user guide (notepad) if it will fit CD, an installation package. X-axis propagation axis, Y-axis horizontal parallel to dipole elements, Z-axis vertical, center or origin at signal source. JBC © 198 v A2,2

Com3 2Q1617 Antenna Design Design objective Design an antenna for DTV GMA, using model X and Y as patterns Driven horizontal dipole element + a parasitic mesh reflector Corner reflector with angle of 90 degrees Cylindrical reflector with parabolic cross section Use AWG10 solid bare copper wire or aluminum tube as wire element. Add a parasitic dipole director, optimize for gain by varying distance from driven element – thus you have to repeat the simulations at different distances All groups to use the same power setting, etc… Methodology Simulate using NEC, choose best then fabricate one prototype Design results Radiation profiles 2D V/H 3D, antenna schematic, gain, beamwidth impedance; prototype with balun and interconnect to TV+ Comparative analysis: Compare of best of corner vs best of cylindrical Prototype fabrication no metallic materials for boom, glue and support structures. Easy to disassemble for easy transport, structurally sound when assembled. JBC © 198 v A2,2

2Q1617 Model X 8/1/2018 Driven half wavelength dipole at these 2 distances 0.1 and 0.2 wavelength from common reflector. Reflector is a cylindrical parabola, shorted at the two ends and with 5 horizontal elements to comprise the mesh, all wires electrically connected There are 7 wires, 2 of parabolic shapes. Set focus is 0.2 wavelengths The width of the cylinder or lengths of the horizontal elements 105% of length of dipole. Horizontal elements equally spaced The driven dipole should be in the plane of the mouth of the reflector at 0.2 wavelength Provide one parasitic director with distance optimized for gain with a length of 95% of driven element 105% JBC © 198 v A2,2

8/1/2018 2Q1617 Model Y Driven dipole at 0.1 and 0.2 wavelengths (same as model X) from center of 90 degrees corner reflector 90 degrees corner reflector shorted at the ends and comprised of 5 equally spaced vertical horizontal wire elements to comprise the mesh The width of the reflector 105% of driven dipole, the height same as the diameter of the mouth of the parabola used in X Provide one parasitic director with distance optimized for gain with a length of 95% of driven element