Introduction: What is an antenna?

What is an antenna?

         As we all know, an antenna is a device that converts electric energy (electric signal) into electromagnetic waves and transmits them to space.

      There are various types of antennas out there. Here are some examples. These are just some examples, and there are many other types. See how many you are familiar with. Nowadays, in most mobile communication devices, antennas are embedded in a small space. In a relatively old mobile phone, you may have seen the picture of the antenna displayed on the left (whip antenna). In most mobile devices, you see these days that the antenna is embedded, or the correct printed circuit board is shown below. As mobile devices (such as smart phones) acquire more and more technologies in one device (such as cellular technology, Bluetooth, wireless network, etc. with various frequency bands/wireless access technologies), it becomes more and more difficult to design multiple antennas and put them in a small space. 

How to show the performance of antenna? 

       There are two main criteria to evaluate the performance of antennas, as follows (a) I should convert electric energy into electromagnetic energy to minimize the loss; (b) I hope the radiation is in the direction I need.

    Several indicators can represent the performance of the antenna as follows:

    1、 Radiation model;

    2、 Total radiation power;

    3、Total isotropic sensitivity. 

    4、Gain of antenna (G/DBi)

Wifi Antenna, Router Antenna, Patch Antenna