antenna frequency

When free space is the communication channel, antennas radiate and receiver the signal. Theory shows that the antennas operate effective only when their dimensions are of the order of the magnitude of wavelength of the signal being transmitted...

. It is seen that the frequency, which makes a given distance correspond to the skip distance, is the MUF for that pair of points. At the skip distance, only the normal or lower ray can reach the destination, whereas at greater distances, the upper ray can be received as well, causing int..

In this, an individual stimulates other members of the same species by physical contact. Different messages are communicated by varying the frequency, pressure and duration of contact. For e.g., Mutual preening in birds. Grooming in primates/mammals. Ants use contact through ..

.C circuit behaves like a pure resistive circuit is called resonant frequency. The following diagram shows the variation of frequency with I o . Notice that as the value of R decreases, the value of I o increases. Since the circuit behaves like a pure resistive one, the current ..

. This is made up by energy diffracted down- ward from the upper portions of the wavefront. There is another way in which the surface wave is attenuated. Because of diffraction, the wavefront gradually tilts over, as shown in the below figure. As the wave propagates over the Earth, it tilts over mo..

Basic Principles of Wireless Radio Communication - Let us now discuss the basic principles of wireless radio communications. We shall mainly concentrate on the principle of amplitude modulation and demodulation. The simplest scheme of wireless communication would be to convert the speech or music t..

. A good quality service can be continuously ensured by a global operational satellite system. Thus, communication satellites would give a valuable service in addition to the submarine cable and high frequency radio systems. Geostationary communication satellites have enabled not only nat..