The other way, help needed (from pattern to antenna)

Hi all,

I was wondering if there's any software to calculate an antenna setup with kind of predefined antenna's from a radiation pattern.

I work for an small radio station (max 100w erp, fresuency is 107.5 Mhz) and we must confirm to a radiation pattern from the governement.

If we don't comply to this pattern our erp is recalculated in acoordance to the difference with the pattern.

I can use nec/eznec etc to calculate patterns with trial and error, but are there specific packages to this problem.

We can use all antenne's with respect to mechanical conditions (panel antenna's for example are too heavy for the tower), but combinations from dipole's, yagi's etc are possible, use of the tower as reflector is possible, phase shifts in feeding lines are also possible, but the trial and error method (create a setup, calculate, change setup etc) is far too time consuming.

Just for information purposes 'ive attached to pattern to which we must confirm (or as close as possible)


Any help, hints, solutions etc are very appreciated

It looks like four directive antennas pointed in the indicated direction plus one nondirectional one could be fed from the output of a five way power splitter with appropriate division ratios.

I am afraid the antenna does not compose of four directive antennas, in fact it is just one omni-directional antenna. Why? Because the user has not use appropriate scale in the polar chart. Usually we use at least 20dB range/scale, while the users only used 5dB range. Hence the 4 ripple-like effect is apparent on the graph, but should not be concerned.