Definition: A type of antenna with an opening cut of certain dimensions in a metallic conductor which is excited using a two-wire transmission line or coaxial cable is known as a slot antenna. These antennas operate in the frequency ranging between 300 MHz to 30 GHz. It is generally formed by making an elongated slot …
Definition: An instrument that is used for the analysis of the frequency spectrum of the input signal is known as a spectrum analyzer. It uses frequency domain representation of the RF signals in order to show the relative amplitude level of the signal at various frequencies within a particular range. A signal which shows the …
Definition: A type of antenna which is formed by bending of a coil or uniform wire in the form of loop is known as a loop antenna. Basically, in loop antenna, the RF current-carrying coil is bent to various shapes like circle, square, rectangle, ellipse, etc. Thus we can say it as a current-carrying coil …
Definition: The input impedance of antenna is basically the impedance offered by the antenna at its terminals. It is defined as the ratio of voltage to the current across the two input terminals of the antenna. Generally, the antenna impedance is given as: We have already discussed in our previous article that antennas are used …
Definition: A part of the electromagnetic spectrum that holds the least frequency range and highest wavelength is known as the radio frequency spectrum. It is sometimes referred as radio spectrum or radio wave spectrum. Generally, the radio spectrum has a frequency range between 30 kHz to 300 GHz. We know that an electromagnetic spectrum contains …
Definition: Fading in wireless communication is defined as the fluctuation in the strength of the signal received at the receiver. These are basically unwanted variations introduced at the time when the signal propagates from an end to another by taking multiple paths. Fading is said to be a common characteristic of sky wave signals that …
Definition: Sudden Ionospheric Disturbances generally abbreviated as SID is a type of ionospheric abnormality which is a result of solar flares. Basically solar flares cause an abrupt increase in the ionization density in the D region of the ionosphere. Thus it is said that SID is an outcome of solar flares. SID basically causes absorption …
Definition: A radio wave propagation technique that allows the transmission of UHF and VHF electromagnetic waves through the region near the tropospheric layer of atmosphere is known as duct propagation. Basically in duct propagation, despite being reflected from the ionosphere or gliding over the surface of the earth, the waves propagate from an end to …
Definition: Space wave propagation is the type of radio wave propagation in which the radio waves are propagated either directly from transmitting antenna to receiving antenna or by getting reflected from the ground. Basically in space wave propagation, direct transmission of the signal is achieved by line of sight communication. The transmission of a signal …
Definition: A type of radio wave communication in which the electromagnetic wave propagates due to the reflection mechanism of the ionospheric layer of the atmosphere is known as sky wave propagation. Due to propagation through the ionosphere, it is also known as ionospheric wave propagation. The permissible frequency range in the case of sky wave …