This program is an applet for calculating the Height pattern
Height pattern indicates the relationship between antenna height and electric
field intensity when the communication conditions other than the height of the
antennas are fixed.
Although it is generally advisable to set the antennas in a high place in
order to achieve satisfactory communication conditions, in fact electric field
intensity at the receiving point depends on the frequency, communication
distance, and antenna height, varying significantly. The higher the frequency,
the closer the communication distance, and the higher the antenna, the more
the composite electric field varies due to the phase relationship of the
reflected waves and direct waves.
The results for height pattern shown in this applet are calculated with
reflected waves from 1 surface (the ground), and they are different from the
electric field intensity attenuation that actually occurs in the field. In the
actual field, since the radio waves arrive by different routes (multipath),
differences in the times that direct waves and reflected waves arrive occur
(phase difference), and the composite waves are distorted in amplitude and
over time (fading). Therefore, points where there is marked attenuation in
received field intensity and points where it increases occur. If radio
equipment is located at the attenuation points, frequent errors will occur.
The height pattern formula is shown below. However, please note that since the
reflecting surfaces are complete reflectors in this calculation, the results
should be viewed with caution. In an actual environment, it is necessary to
assume reflection loss in relation to reflected waves in any calculation.
Instructions
1. Click the "Figure / Graph" button to display the calculation
screen.
2. Enter the required items in the yellow input fields for entering
parameters. To calculate the Height pattern, after setting the parameters in
the input fields, push the Enter key on your PC, or click the "Calculate"
button.
3. Set the height in the pink input field, "Height : hr". The height pattern
from 0 m to this height is calculated.