1
VISUALIZING THE 3D POLAR POWER PATTERNS AND EXCITATIONS OF PLANAR
ARRAYS WITH MATLAB
J. C. BRÉGAINS, F. ARES, AND E. MORENO
Radiating Systems Group, Department of Applied Physics,
15782 Campus Sur, Univ. of Santiago de Compostela (Spain)
e-mails: (Ares) faares@usc.es - (Brégains) fajulio@usc.es – (Moreno) famoreno@usc.es
ABSTRACT
A few lines of MATLAB M-code suffice to create 3D polar plots of the power patterns of planar
arrays together with 3D plots of the amplitudes and phases of their excitations.
1. INTRODUCTION
Many antenna designers are familiar with MATLAB [1] and use it in their everyday work. However,
many also shy from attempting to exploit its graphical capabilities to the full. Here we present some
quite simple M code that straightforwardly performs a task that is often desirable but is often left
undone or is performed less efficiently by exporting numerical results to an external graphical
program [2, 3]: production of the 3D polar plot of the power pattern of a planar or linear antenna array
of identical radiating elements (or of a single element) given only their positions and excitations and
the corresponding element factor. For good measure, the program also produces 3D plots of the
amplitudes and phases of the element excitations. The code presented has been neither optimized
nor worked up as a stand-alone application or function (we keep it always to hand in the MATLAB
working directory as an M-file named planar_pow3d.m, modifying certain parameters in the code itself
whenever necessary), and nor does it include exhaustive measures to prevent undesired results
when given illegitimate data such as negative excitation amplitudes; but anyone familiar with MATLAB
will easily be able to adapt it to their own requirements.
2. THE CODE
In this section we run through the M code for Figs.1-3, which show power and excitation plots for
a 20 x 20 planar array of isotropic elements located 0.5 apart, the excitations of which are the result
of multiplying (i.e., by using separable distributions [4]) those of a -20 dB Chebyshev linear array [4]
with those of a linear array generating a flat-topped pattern with a half-power beamwidth of 43.2º and
a maximum side lobe level of -20 dB [5]. To facilitate commentary, line numbers have been added to
the code.
