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The Maxwell Garnett formula, in contrast to Bruggeman formula, ceases to be correct when the inclusions become resonant. In the case of plasmon resonance, the Maxwell Garnett formula is correct only at volume fraction of the inclusions δ i < 10 − 5 {\displaystyle \delta _{i}<10^{-5}} . [23]
Gain or 'absolute gain' is defined as "The ratio of the radiation intensity in a given direction to the radiation intensity that would be produced if the power accepted by the antenna were isotropically radiated". [1] Usually this ratio is expressed in decibels with respect to an isotropic radiator (dBi).
A parameter often encountered in specification sheets for antennas that operate in certain environments is the ratio of gain of the antenna divided by the antenna temperature (or system temperature if a receiver is specified). This parameter is written as G/T, and has units of dB·K −1. G/T Calculation. G/T is the figure of merit for a ...
Note that the antenna height gains are strictly a function of height and have nothing to do with antenna patterns. Plots of A mu (f, d) and G AREA for a wide range of frequencies are shown in Figure 3,23 and Figure 3.24. Furthermore, Okumura found that G(hte) varies at a rate of 20 dB/decade and G(hre) varies at a rate of 10 dB/decade for ...
Effective height. In telecommunication, the effective height of an antenna is the height of the antenna's center of radiation above the ground. In low- frequency applications involving loaded or nonloaded vertical antennas, the effective height is the moment of the current distribution in the vertical section, divided by the input current.
Line-of-sight propagation. Line-of-sight propagation is a characteristic of electromagnetic radiation or acoustic wave propagation which means waves can only travel in a direct visual path from the source to the receiver without obstacles. [1] Electromagnetic transmission includes light emissions traveling in a straight line.
Friis' original formula. Friis' original idea behind his transmission formula was to dispense with the usage of directivity or gain when describing antenna performance. In their place is the descriptor of antenna capture area as one of two important parts of the transmission formula that characterizes the behavior of a free-space radio circuit.
In electromagnetics, the antenna factor ( AF, units: m −1, reciprocal meter) is defined as the ratio of the electric field E (units: V/m or μV/m) to the voltage V (units: V or μV) induced across the terminals of an antenna : If all quantities are expressed logarithmically in decibels instead of SI units, the above equation becomes.