Contents
What is meant by the term radiation resistance for an antenna?
The radiation resistance can be defined as the value of resistance that would dissipate the same amount of power as radiated as radio waves by the antenna with the antenna input current passing through it.
What is radiation intensity of antenna?
Radiation intensity, or the antenna power pattern, in a given direction is defined as the power radiated from an antenna per unit solid angle. The radiation intensity is a far field parameter which can be obtained by simply multiplying the radiation power density by the square distance, i.e., (2.99)
What is the radiation resistance of λ 2 antenna?
λ/2 Dipole or Half-wave dipole: Length of dipole = λ/2. Directivity = 1.64 or 2.15 dBi. Impedance for half-wave dipole antenna in free space is 73 Ω
How is antenna radiation calculated?
The directivity of an antenna in a given direction is the ratio of the radiation intensity in this direction and the average radiation intensity: (9) The average radiation intensity is the total radiated power of the antenna averaged over all directions [i.e., U av = P r / ( 4 π ) ] since a sphere has steradians.
What is average radiation intensity?
From meteorological data of Table 1, Covenant University has been found to have a high annual average solar radiation intensity of 414.89W/m 2 , making it a desirable location for the installation of solar water heaters for domestic use.
What material can block radiation?
Materials that block gamma radiation: Lead aprons and blankets (high density materials or low density materials with increased thickness) Lead sheets, foils, plates, slabs, pipes, tubing, bricks, and glass. Lead-Polyethylene-Boron Composites.
How do you calculate the impedance of an antenna?
measure antenna impedance you can measure the antenna impedance using the value of s11, simply by determining the input impedance from s11, normalizing, placing the normalized impedance on smith chart then moving toward the load by a length equal to that of the feeding line. the point you will reach is the normalized input impedance of the antenna.
What is antenna efficiency?
Antenna Efficiency. The efficiency of an antenna is a ratio of the power delivered to the antenna relative to the power radiated from the antenna.
What is radiation impedance?
Radiation impedance is the resistance a diaphragm sees when it moves air to create a soundwave . It creates sound pressure and feels this pressure as opposed to it’s movement.