Impact of 5G Base Stations on C-band Earth Station Antennas
Satellite communication is a wireless communication method that uses satellites as the communication medium. In previous articles, we introduced satellite communication systems of parabolic antennas in detail, mainly analyzing parabolic antennas. Today we are going to introduce another type – phased array antennas.
Antesky Earth Station Antenna Projects of parabolic antennas
Phased array antenna is a type of satellite communication antenna. Phased array antenna changes the shape of the radiation pattern by controlling the feeding phase of the radiating element in the array antenna, thereby achieving beam scanning and signal transmission. In satellite communications, phased array antennas are widely used in communication services such as satellite telephone, fax, email, data connection, position reporting, and fleet management.
Phased Array Antenna
From the figure, we can see that there are obvious differences between phased array antenna and parabolic antenna:
-The height of the antenna is low.
-There is no mechanical transmission device;
A phased array antenna is an array of antennas with electronic beam pointing capabilities that can change the direction and shape of the radiated signal without moving the antennas. The phase difference between the signals radiated by each antenna in the array is responsible for this electronic beam pointing.
The basic principle of a phased array antenna is the phase-dependent superposition of two or more radiated signals. When the signals are in phase, they combine to form a signal whose amplitudes are added. When the signals are out of phase, they cancel each other out.
The three types of phased array antennas are: 1) linear array, 2) planar array, 3) frequency-scanned array.
Phased array antennas are becoming increasingly popular in 5G communication technology
Have you ever watched ants carry sugar cubes? The size of the sugar cube is much larger than the size of the ant. This natural behavior proves that a team working in the same direction can accomplish the same goal in a shorter time.
In wireless transmission, antenna arrays operate on the same concept – a team working together can achieve more than a single unit doing the same work. Phased array antennas use this principle to achieve greater signal strength, gain, directivity, and performance than a single antenna.
How do phased array antennas work?
Phased array antennas include multiple transmitters and are used for beamforming in high frequency RF applications. Three common application areas are WiFi, chirp radar, and 5G. The number of transmitters in a phased array antenna can range from a few to thousands. The goal of using a phased array antenna is to control the direction of the transmitted beam by exploiting constructive interference between two or more radiated signals. This is known as “beamforming” in the antenna world.
Phased array antennas achieve beamforming by adjusting the phase difference between the drive signals sent to each transmitter in the array. This allows the radiation pattern to be controlled and pointed at a target without requiring any physical movement of the antenna. This means that beamforming along a specific direction is the effect of interference between omnidirectional transmitters, such as dipole antennas used in WiFi.
This phased array antenna contains multiple transmitters that produce a highly directional radiation pattern.
When the signals from each transmitter in a phased array are exactly in phase, they constructively interfere and produce strong radiation, but this only happens along a specific direction. The direction is controlled by setting the phase offset between the signals sent to different transmitters. The phase offset is controlled by placing a slight time delay between the signals sent by consecutive transmitters in the array. Outside the direction the main beam is emitted, the beam strength is reduced. Since the signal is periodic, there will also be side lobes in the beam pattern, but you do get a very strong beam along a specific direction.
When the signals from each transmitter in a phased array are exactly in phase, they constructively interfere and produce strong radiation, but this only happens along a specific direction. The direction is controlled by setting the phase offset between the signals sent to different transmitters. The phase offset is controlled by placing a slight time delay between the signals sent by consecutive transmitters in the array. Outside the direction the main beam is emitted, the beam strength is reduced. Since the signal is periodic, there will also be side lobes in the beam pattern, but you do get a very strong beam along a specific direction.
Advantages of Phased Array Technology
Beamforming is necessary at high frequencies (around WiFi frequencies and higher) to overcome losses during transmission. Using a properly sized phased array antenna, the radiation from a high gain transmitter can be directed over a wide solid angle.
Phased array technology helps enhance the characteristics of the collective signal or radiation pattern. The characteristics of the individual signals from the radiator and the collective signal from the phased array antenna are like separate poles. The enhancements in various parameters and quantities when arraying can be summarized as follows:
- Power – The power of the collective signal is the sum of the individual signal powers, therefore, the strength is increased.
- Beamforming – The shape of the beam can be controlled by the phase difference of the individual signals and the radiation pattern of the phased array antenna, which results in a narrower radiation pattern than a single antenna.
- Beam pointing – Mechanical repositioning is eliminated, making beam pointing or beam positioning more flexible. Beam pointing is established by using electronically variable phase shifters.
- Multi-beam – Hundreds of beams can be synthesized in a phased array antenna with the help of phase shifters.
- Digital or Mixer Options – Phase shifting can be done analog or digitally. Analog phase shifters rely on down-conversion and time-shifting of the signal. Digital methods shift the phase of the intermediate frequency (IF) mixer or local oscillator (LO) signal.
- Weight – Phased array antennas weigh less than mechanically steered single antennas.
- Cost – Mechanically steered antennas can be replaced with cheaper phased array antennas while maintaining the same resolution.
- Reliability – Phased array antennas are much more reliable than single antennas. If one array antenna is damaged, the remaining antennas in the array will continue to operate with a slight modification of the radiation pattern.
Types of Phased Array Antennas
Phased array antennas are classified into three types based on the arrangement of individual antennas and the number of phase shifters. The classification is as follows:
Linear array: The array elements are arranged in a straight line with only one phase shifter. Despite the simple antenna arrangement, the beam pointing is limited to one plane. A vertical arrangement of several linear arrays forms a planar antenna.
Linear array antenna
Planar array: For each antenna in a planar array, there is a phase shifter. A matrix arrangement of individual antennas forms a planar array. The beam can be deflected in two planes. The disadvantage of a planar array antenna is that a large number of phase shifters are required.
Planar array antenna: a) side view b) top view
Frequency Scanned Array: If the beam pointing control is a function of the transmitter frequency, then the phased array antenna using this technique is called a frequency scanned array antenna. In a frequency scanned array antenna there is no phase shifter and the beam pointing is controlled by the transmitter frequency.
Frequency scanning array antenna structure b) Wave propagation direction
5G communications require key technologies such as multiple access, multi-beam, high gain, and ultra-dense networks. Antenna designers are ready to use phased array antennas to meet the requirements of wireless communication systems.
In particular, phased array technology that provides electronic beam pointing is an asset to RF wireless communication systems. With phased array antennas, you can electronically enhance the direction, strength, and shape of the transmit or receive beam without losing resolution.
Above is the brief introduction about advantage, principle and classification of Phased Array Antenna. Hope it is helpful for you in the future use. ANTESKY SCIENCE TECHNOLOGY INC. was built in 1985, we’re mainly engaged in the design and manufacture of satellite communication large satellite dish,VSAT antenna,TVRO antenna, Portable flyaway antenna and relevant control and tracking system. We have a selected range of antenna in the frequency band, such as C-band, Ku-band, X-band, L-band, S-band, Ka-band, DBS-band.
If you are looking for such portable flyaway antenna or any other satellite communication dish, please send Antesky an inquiry via sales@antesky.com. Thanks!
Related posts
