What is the antenna impedance?
The antenna impedance is a measure of resistance to the electrical signal in the antenna. Many factors have an impact on the ability of the antenna to transmit a signal, including the environment in which there is an antenna, and the design and composition of the antenna. Understanding the impedance of the antenna is important when designing components that connect the antenna to the receiver or transmitter.
The voltage ratio to the current equal to the impedance of the antenna is expressed in units called Ohms. The antenna impedance is a power absorbed by an antenna, as well as a power that is scattered when it comes into contact with an electromagnetic wave. Different wavelengths of electromagnetic radiation will provide the same antenna with different impedance values.
In electronics, ohms are a measure of resistance in the wire and zero ohm measurement means that there is no resistance, while measurement of endless ohms suggests that there is a complete resistance. Antenna impedance would be zero ohms if the voltage and current remain the same from one point in the antenna to another. However, this never applies inAntennas in the real world that generally have an antenna impedance somewhere between 15 and 1,000 ohms.
Environmental factors may have an impact on the antenna impedance. Objects around the antenna, the height of the antenna above the ground and whether the antenna is closed inside or exposed to elements, all changes its resistance when exposed to an electromagnetic signal. Under optimal conditions, a simple half -wave dipole would have an antenna impedance of 75 ohms. The coaxial cable, which is used in conjunction with half dipole antennas for the transmission of television signals, corresponds to this impedance and also has an impedance of 75 ohms.
Impedance comparison is an important aspect in designing antenna -moon of various types. Because this involves the transmission of electricity through the antenna. The antenna must transfer this information to a receiver, allowing human observers to collect information picked up by the antenna. This information goes through antennaU and various other cables, such as a coaxial cable that brings information to TV. Finding cables that correspond to the same voltage ratio to the current helps maintain the signal strong and clean as it passes from one device to another.