(Last Updated On: June 27, 2021)
Why Most Boosters and Amplifiers are Metal Made?
The cell phone signal repeater becomes an essential part of our daily lives due to signal problems while making voice calls and using the internet. All repeater kits have three main parts, an outdoor antenna, an amplifier, and an indoor antenna. Amplifiers have an electronic-based architecture. However, antennas are mostly made up of metals and serve the cross-transmission of signals.
Antennas, depending on their purpose, are subdivided into receiving, transmitting, and receiving-transmitting. An antenna in the transmission mode converts energy from the radio transmitter into an electromagnetic wave propagating through space. An antenna in the reception mode converts power from an electromagnetic wave incident into an electromagnetic oscillation entering the radio receiver.
The shape, size, and design of subsequently created antennas are incredibly diverse and depend on the operating wavelength and purpose of the antenna. Antennas are made in the form of a piece of wire, a system of conductors, a metal horn, metal and dielectric waveguides, waveguides with metal walls with a system of cut slots, and many other types have found widespread use.
The radiating part of antennas, as a rule, is made using materials (metals) conducting an electric current. Still, it can be made of insulating (dielectric) materials, semiconductors, and metamaterials can be used.
From the point of view of the electrical circuits theory, the antenna is a two-pole (or multiple), and the source power released on the active component of the antenna’s impedance is spent on creating electromagnetic radiation. In control systems, the antenna is an angular discriminator – a sensor of the angle of misalignment between the direction to the radio signal source or reflector and the direction of the antenna.
Simplified, the principle of operation of the antenna is as follows. As a rule, the antenna structure contains metal (conductive) elements electrically connected (directly or through a power line – feeder) to a radio transmitter or receiver.
In the transmission mode, an alternating electric current generated by a source (for example, a radio transmitter), flowing through the conductive elements of such an antenna, following Ampere’s law, generates an alternating magnetic field in the space around it. This time-varying magnetic field, in turn, not only affects the electric current that developed it under Faraday’s law but also created a time-varying vortex electric field around itself.
This alternating electric field creates an alternating magnetic field around itself. So on – a corresponding alternating electromagnetic field arises, forming an electromagnetic wave that propagates from the antenna into space.
We can say that the antenna plays the role of converting electric current energy into electromagnetic energy and vice versa. In the receiving mode, the alternating electromagnetic field of the wave incident on the antenna induces currents on the conductive elements of the antenna structure, which are fed to the load (feeder, radio receiver). Induced currents generate voltages at the input impedance receiver.
Now, you might have got an idea of why repeater antennas are made up of metals.
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