Antennas allow data to be transmitted further, then how to choose the right antenna?

An antenna is an energy converter that converts traveling waves propagating on a transmission line into electromagnetic waves, radiating them into space. What is the conversion process of electromagnetic waves that we cannot see or touch?

This problem is difficult to understand, especially for beginners. In daily life, we encounter various converters, and generally we do not have a deep understanding of them. A speaker is a common converter that converts audio current in a radio into sound waves. Sound waves reach our ears through air, and the ears sense them, so that we can hear the sound. So, a speaker is something that converts electrical energy into sound energy. But conversely, speakers can also convert sound energy into electrical energy. When the speaker is used in this way, it becomes a microphone. 

In the field of communication technology, antennas play an important role. Both transmitters and receivers require antennas. A suitable antenna can optimize the network, increase communication range and reliability, while an inappropriate antenna can lead to a decrease in communication quality. Since antennas are so important, MIDE will introduce in one sentence what antennas are, their principles, and how to choose them correctly.

What’s the antenna?

An antenna is a device that converts an electric field into electromagnetic waves.

What is the principle of an antenna?

The antenna converts the electric field into a magnetic field, forming an electromagnetic wave to transmit signals, while in the opposite direction, the magnetic field is converted into an electric field, which is then transmitted to the device through a line, thereby forming the transmission and reception of wireless signals.

An antenna is a device that radiates or receives radio frequency signals from a transmission line into the air. It can also be seen as an impedance converter or energy converter, which converts traveling waves propagating on a transmission line into electromagnetic waves propagating in an unbounded medium, and vice versa.

The design and selection of antennas are important components of designing wireless transceivers in RF systems. A good antenna system can achieve optimal communication distance. The size of the same type of antenna is proportional to the wavelength of the RF signal. The lower the signal frequency, the larger the antenna required.

So how should we choose the appropriate antenna? Starting from antenna parameters: frequency, matching impedance, voltage standing wave ratio, gain, and polarization. For wireless communication products (such as wireless data transmission modules), the specifications specify common antenna operating frequencies and gains.

1、Operating Frequency

Antennas are used to transmit and receive electromagnetic waves, just like converters, converting current into electromagnetic waves and then converting electromagnetic waves back into current. Finally, the most important parameter is the operating frequency. For example, a 2.4 GHz antenna is used for communication with devices operating in the 5G frequency band, which may result in very poor signals or reduced transmission rates.

2、Gain

Antenna gain represents the energy concentration and conversion efficiency of the antenna towards the signal. Increasing the gain of wireless communication is not to amplify the signal, but to concentrate the energy of the signal. The gain will affect the working direction of the antenna. Generally speaking, the higher the gain, the stronger the directionality of the antenna. Otherwise, the radiation distribution in all directions is more uniform.

Classification of antennas

Antennas can be divided into external antennas and internal antennas based on their installation location. Those installed inside the device are called internal antennas, while those installed outside the device are called external antennas.

For small-sized products such as handheld devices, wearable designs, and smart homes, built-in antennas are commonly used, with high integration and beautiful appearance. The Internet of Things and intelligent hardware products require the use of antennas to transmit data through the internet. The smaller the space and the more frequency bands, the more complex the antenna design. External antennas are generally standard products, and can be used by selecting the desired frequency band antenna without debugging, plug and play.

As a radio transmitting and receiving device, antennas are important devices that affect signal strength and quality, and their importance in the field of mobile communication is crucial. By selecting, installing, and adjusting antennas, the signal strength and quality within the coverage area of the base station can be guaranteed. A high-quality and suitable antenna can improve communication quality and expand communication range.