Height pattern calculation tool

By entering frequency, height of transmitter antenna and communication distance it is possible to calculate the pitch of the height pattern.

❶ Enter the user frequency in MHz

Frequency  MHz

❷ Enter the transmitter antenna height in metres

Height  m

❸ Enter the communication distance from base station in metres

Distance  m

Height pattern pitch

What is the height pattern pitch?

The overall power of the received wave due to the combination of the direct and reflected wave will change due to the phase difference. This behaviour is described as the height pattern. The constant interval between the peaks (or troughs) in the level as shown in the diagram below is the height pattern pitch. Higher frequencies (shorter wavelengths) will produce narrower intervals, as will varying the communication distance.

Sometimes it is not just about moving the antenna up higher. After placing the antenna, you can then adjust the antenna height within this pitch value to coincide with the maximum value in the height pattern.

Formulas used on this page

Radio wave frequency: f(MHz)

Wavelength: λ(m)

$$ λ=\frac{c(^m/_s)}{f(MHz)}=\frac{3\times10^8}{f\times10^6} $$

Transmitter antenna height: ht(m)

Distance from transmitter antenna: d(m)

When d >> ht, the height pattern pitch p(m) can be expressed as:

$$ \large p(m)=\frac{λ}{2} \frac{d}{h_t} $$