Plotting aerial pattern with Excel

Created: Jun. 2023

Plotting aerial pattern allows determination of its beamwidth, front-to-back ratio, and whether the balun is doing its job in suppressing current outside the coax. Although aerial pattern can be plotted on graph paper but it is difficult to modify or to share electronically. For those who do not have a dedicated aerial simulation software, Excel provides a convenient mean to plot the pattern (fig. 1).

Fig. 1: Excel worksheet for plotting aerial pattern

To convert the gain vs. angle (azimuth) data to graph coordinates, the following formulae were entered into the Excel columns X and Y (fig. 2):

X=(40+B6)*COS(A6*PI()/180)

Y=(40+B6)*SIN(A6*PI()/180)

The value "40" is a scaling factor chosen because the graph is intended have a 40 dB total range. The "40" is added to the data in column B to obtain the radius. As the angle in column A is in degrees, whereas Excel requires radian, it is converted by dividing by 180 and multiplying with PI.

Fig. 2: To convert the gain vs. angle (azimuth) data to graph coordinates, the shown formulae were entered into the Excel columns X and Y

The graph has reference circles for 0/-10/-20/-30 dB. These circles are plotted using the previously described formulae for converting polar data to X & Y coordinates.

Fig. 3: Cells for plotting reference circles (0/-10/-20/-30 dB). The formulae for the X & Y coordinates are shown at the top & bottom of the image

To download the spreadsheet below, click the expand button on top right. Then, on the newly opened page, click the download button on the top right.

patt_180deg.xlsx