Aligning center of bicone antenna and reflector in Antenna Toolbox

Hi All,

I'm trying to simulate a bicone antenna with flat sheet reflector using antenna toolbox. Using antennaDesigner I can create the two objects, and I rotate both about the x axis by 90 degrees to get the correct orientation.

However the center of the bicone is not aligned with the center of the reflector, making the model unuseable. Is there a way to move or shift the bicone so the center feedpoint is at 0mm? At the moment, the end of the cone is positioned at 0mm.

I see a translate function exists for custom shapes but nothing for the standard models. I guess I could try creating a custom shape for the reflector and aligning to the bicone, but the standard library should work....

Any ideas?

% Create a bicone antenna backed with reflector
% Generated by MATLAB(R) 9.10 and Antenna Toolbox 5.0.
% Generated on: 22-Aug-2021 21:03:56

%% Antenna Properties 

antennaObject = design(reflector('Exciter', bicone), 1000*1e6);
antennaObject.Exciter.BroadRadius = 0.033;
antennaObject.Exciter.Tilt = 90;
antennaObject.GroundPlaneLength = 0.2;
antennaObject.GroundPlaneWidth = 0.2;
antennaObject.Tilt = 90;
% Show
figure;
show(antennaObject) 

[Tim Bolton]

Great, thank you Johnny. A bit of a work around but it gets me up and running.

Tim

Answer 1

[Johnny Himbele]

Hi Tim,

A reflector function does not allow user to translate postiions of reflector and exciter. But you can still create a bicone + reflector (ground plane) model using a conformalArray as described at this page.

To create a bicone + reflector model, please refer to the following example.

    % Step 1: Create a ground plane (reflector) model
    >> rect = antenna.Rectangle("Length",0.2,"Width",0.2);
    >> p = getShapeVertices(rect);
    >> ant1 = customAntennaGeometry;
    >> ant1.Boundary = {p};
    
    % Step 2: Create a bicone model
    >> ant2 = bicone;
    >> ant2.Tilt = 90;
    >> ant2.BroadRadius = 0.033;

    % Step 3: Create a custom conformal array
    >> c = conformalArray('Element',{ant1,ant2});
    >> c.AmplitudeTaper = [0,1]; % Excitation amplitude of ant1 (= reflector) is set to 0 which is considered as a dead element
    >> show(c);  % Display a bicone + reflector model whose feed point is aligned to the center of model space

Johnny