Mounting a dipole antenna at a height greater than or multiple of its wavelength can have several effects on the radiation pattern and power being transmitted. Here are a few key considerations:
Radiation Pattern: The height of the dipole antenna affects the shape and direction of its radiation pattern. When a dipole antenna is mounted at a height greater than or multiple of its wavelength, the radiation pattern tends to have higher elevation angles and a more vertical orientation. This can result in more energy being radiated upwards and downwards rather than towards the horizontal plane.
Lobes and Directivity: The lobes of the radiation pattern represent the regions of maximum radiation intensity. Mounting a dipole antenna at a height greater than or multiple of its wavelength can alter the shape and directivity of these lobes. The specific changes depend on the configuration and height relative to the wavelength, but generally, the radiation pattern becomes more multi-lobed and less directive compared to a dipole antenna mounted at a half-wavelength height.
Gain and Power Distribution: The gain of an antenna is a measure of its ability to direct power in a particular direction. When a dipole antenna is mounted at a height greater than or multiple of its wavelength, the gain of the antenna may be reduced, and the power distribution may become more spread out over a wider area. This can result in a decrease in the efficiency and effective radiated power of the antenna.
It's important to note that the specific effects will depend on the height of the dipole antenna relative to the wavelength and the surrounding environment. Antenna design and placement considerations are crucial to achieve the desired radiation pattern and maximize power transmission efficiency.