What is an active antenna and passive antenna?
Thanks to the dynamic development of television broadcasting in the modern world, there is probably no person who does not encounter antennas. In order to watch their favorite TV shows in the best quality, the user needs to connect the antenna to his receiving equipment. And then the question arises: which antenna to choose, active or passive? In this article, we will consider in detail the features of each antenna, as well as the scope of their application. But first of all, it is necessary to give a detailed definition of the very term “antenna” and briefly describe the history of creation.
Heinrich HerzAntenna is a special device whose main task is to receive or emit radio waves. It converts the fluctuations of the electric current into a radio wave or vice versa. As can be seen from the definition, antennas can operate on reception, transmission, or transmission. The simplest antenna operation scheme is as follows: a television or radio device produces a signal that is amplified and transferred to a transmitting antenna. The antenna, in turn, propagates this signal in the form of radio waves. In the process of wave propagation, the receiving antennas reach, which fix them and transmit them for processing, followed by output to the finished devices in the format of the original signal. Each stage of operation of the antenna may be accompanied by certain interference arising from other sources of radiation or features of the terrain.
The creator of the antennas was the famous German physicist Heinrich Hertz. It was he who in 1888 manufactured the first such device in order to confirm the presence of electromagnetic waves. Of course, since that time, antennas have changed significantly both externally and functionally. Today we will only touch on the classification according to the level of activity of the antenna, although there are a rather large number of different types and types of antennas.
Passive Antenna A passive antenna receives all signals only due to its shape. There are no additional amplification devices and other electrical equipment. Based on this, we can conclude that the reception power directly depends on the area of the device. A passive antenna has the following advantages:
does not interfere, since there are no devices in it that can produce an electromagnetic field;
ease of installation and subsequent use, the only thing necessary is to make the correct orientation on the ground;
does not need a special power source;
minimum probability of failure (by and large there is nothing to break there);
if desired, the PA can be assembled independently, since the design is extremely simple and includes only a few elements (frame and wire).
Passive antenna If you are already inspired and began to craft a passive antenna, do not rush. The passive antenna also has a number of disadvantages:
dependence of the level and quality of the received signal on the location;
susceptibility to various kinds of interference (climatic conditions, terrain, nearby objects, electromagnetic radiation, etc.);
the need to create a large canvas for good reception.
Passive Antenna: Pins
It should be remembered that a passive antenna can be installed both at home (indoors) and outdoors. Naturally, when choosing an antenna, you should immediately consider the installation site.
Summing up, we can say that the passive antenna justifies its installation in the area with a good signal, where additional amplification is not required. Most often, a passive antenna is used in urban apartments.
Antenna In the design of the active antenna, an additional device is mandatory, which amplifies the received signal and delivers it to the receiver. It can be various decoders, suppressors, amplifiers, etc. This device can already be integrated into the antenna or mounted on its surface. For its operation, a standard 220V power supply is required, obtained either from a wall outlet or from a rechargeable battery.
An active antenna boasts the following advantages:
a wide selection of various shapes and sizes;
installation in almost any territory, since the terrain (and weather) features do not significantly affect the operation of the active antenna;
signal amplification of any power and compensation for interference and noise;
ability to catch a wide range of signals;
adjusting reception settings.
Iridium / GPS Magnetic Mount It would seem that an active antenna is the best option for a receiving device. Do not argue, she really was much ahead of her “passive” sister. But after the undeniable advantages, there are several disadvantages:
high cost; in this case, do not chase for cheap options, otherwise you run the risk of getting a model with a poor-quality amplifier, which makes the purchase absolutely useless;
complexity of execution (it’s unlikely to fix it yourself);
the need for a constant power source;
an active antenna can interfere with itself