What is meant by radiation resistance?
Definition of radiation resistance : the component of antenna resistance that accounts for the power radiated into space and is equal in ohms to the radiated power in watts divided by the square of the effective current in amperes at the point of power supply.
What is the antenna resistance?
[an′ten·ə ri‚zis·təns] (electromagnetism) The power supplied to an entire antenna divided by the square of the effective antenna current measured at the point where power is supplied to the antenna.
Why is the value of the radiation resistance of an antenna important?
Why is the value of the radiation resistance of an antenna important? Knowing the radiation resistance makes it possible to match impedances for maximum power transfer. Knowing the radiation resistance makes it possible to measure the near-field radiation density from transmitting antenna.
What happens when the radiation resistance of an antenna?
Explanation: When the radiation resistance of the antenna matches the characteristic impedance of the transmission line, the SWR is minimum and maximum power reaches the antenna. This allows maximum power to be transmitted.
What is the difference between ERP and EIRP?
EIRP is the Effective isotropic radiated power is the total power radiated by a hypothetical isotropic antenna in a single direction. ERP is Effective Radiated Power is the total power radiated by an actual antenna relative to a half-wave dipole rather than a theoretical isotropic antenna.
Do antennas have resistance?
Due to electromagnetic reciprocity, an antenna has the same radiation resistance when receiving radio waves as when transmitting. The power dissipated in the radiation resistance is due to radio waves reradiated (scattered) by the antenna.
What is radio polarization waves?
Polarization describes the way the electric field of the radio wave is oriented. But when waves are generated from, or passed through an intentionally polarizing device, such as an antenna, the fields are restricted in movement and are said to be “polarized.”
What is feed impedance?
Antenna feed impedance basics The feed impedance of the antenna results from a number of factors including the size and shape of the RF antenna, the frequency of operation and its environment. The impedance seen is normally complex, i.e. consisting of resistive elements as well as reactive ones.
What is power radiated in antenna?
ERP measures the combination of the power emitted by the transmitter and the ability of the antenna to direct that power in a given direction. It is equal to the input power to the antenna multiplied by the gain of the antenna.
What is radio ERP?
ERP stands for effective radiated power. ERP is simple. It is the output power of the transmitter, plus the gain of the antenna, minus the attenuation and losses incurred by cable runs and connectors in-between the transmitter and antenna.
Which is the best definition of electrical resistance?
Electrical resistance is defined as the property of an electrical component to resist the flow of electric current. The unit of electrical resistance is ohm which is defined as volt per ampere.
How are resistivity and resistance of a circuit related?
The electrical resistance of a circuit component or device is defined as the ratio of the voltage applied to the electric current which flows through it: Whether or not a material obeys Ohm’s law, its resistance can be described in terms of its bulk resistivity. The resistivity, and thus the resistance, is temperature dependent.
What is the resistance of a conductor in ohms?
The resistance of a conductor is resistivity of the conductor’s material times the conductor’s length divided by the conductor’s cross sectional area. R is the resistance in ohms (Ω). ρ is the resistivity in ohms-meter (Ω×m)
How is voltage measured and how is resistance measured?
Voltage is measured in volts (V). Resistance: Resistance is the opposite force that resists the flow of electrons. The electrons that are moving freely through the conductor will collide continuously with the atoms (which acts as barriers). This causes the free electrons to lose their energy . Hence, the electric current decreases.