4G communication technology has become popular, and the fifth-generation communication technology 5G is also accelerating its commercial use. In this article, LCSC supplier BAT WIRELESS will briefly talk about 5G antenna technology. What changes have been made to the base station’s antenna to bring faster speeds? What are the characteristics of 5G mobile phone antennas?
Features of 5G
5G has the advantages of high speed, massive device connections, low power consumption, low latency and high reliability. However, imagination is beautiful, reality is very skinny, and the implementation process of 5G is full of difficulties. The specific performance is:
- Compared with 4G, 5G has more complex scenarios and higher performance requirements;
- 5G requires a large number of new base stations to achieve ultra-dense deployment;
- 5G also requires a large amount of spectrum resources to achieve ultra-high speeds;
- 5G micro base stations have increased demand for antennas.
The founder of the industry, Shannon, proposed the golden rule in the communications industry: C=B log2 (1+S/N).
The theoretical transmission rate C is directly related to the bandwidth B, which is well understood. The width of the road directly determines the upper limit of traffic flow.
In the same way, to increase traffic flow, instead of formulating more complex road rules (corresponding to various protocols and encoding and decoding rules in communication), it is most effective to increase the number of lanes to increase traffic flow. This is the simplest and crudest way – Princess Hug’s general way.
The spectrum resources of mobile communications are too limited. You can only use a higher frequency band to increase the bandwidth (B). 5G’s millimeter wave solution is like multiple N-lane ultra-wide highways, with the speed limit for each vehicle increased. But here comes the problem. The propagation characteristics of electromagnetic waves are interesting. The higher the frequency, the straighter the propagation path is and cannot be bent. In this case, you have to face the direction of the antenna when making a call. It’s so anti-human. Wise communicators thought of micro base station technology. Think of a shadowless lamp on the operating table, achieving full coverage by adding light sources.
It increases the coverage area and solves the straight-line propagation problem by converting a macro base station into multiple micro base stations. At the same time, the macro base station is no longer responsible for accessing network equipment, but each micro base station does this part of the work. With more grassroots staff, upper-level leaders can manage more people. Another troublesome thing is that high-frequency signal propagation losses are heavy, requiring massive multi-antenna technology (Massive MIMO) to achieve spatial diversity and suppress propagation losses.
MIMO stands for multiple inputs and multiple outputs. There are more channels for parallel communication between the base station and the mobile phone. Each pair of antennas independently transmits a channel of information, resulting in double speed after aggregation. It is a promising technology to consider.
Just like when you are in love and dating, it feels like all other voices except the one you love are just noise. Communicators also thought of using large-scale antenna arrays to control the phase and signal amplitude of each antenna unit’s transmit (or receive) signal to generate a directional beam (like a flashlight), eliminate interference from all directions, and enhance the signal in the direction of the beam.
This full exploitation of space resources can effectively utilize precious frequency band resources and increase network capacity dozens of times. At the same time, we can position the device more precisely.
The length of the antenna is about 1/2 wavelength or 1/4 wavelength. In the 5G millimeter wave era, antennas are getting smaller and smaller, and the number is increasing in pairs. Nowadays, most 4G mobile phones are 2×2, 5G is at least 4×4, and the base station antennas have as many as 128 or 256 antennas. The Internet of Things also requires antennas.
As introduced above, the required antennas will change to a certain extent according to the characteristics of 5G. As for terminals, what are the characteristics of antennas compared to 4G?
5G Mobile Phone Antenna Characteristics
- 5G terminal antennas are very sensitive to surrounding metal.
- Since the wavelength of millimeter waves is very short, interference from metal is very severe. Printed circuit boards (ie PCB boards) need to maintain a clearance of 1.5mm between them and metal objects.
- The 5G antenna is a dot matrix in which vertical and horizontal antennas interact.
- This vertical and horizontal interactive antenna corresponds to the transmission and reception of signals in both vertical and horizontal polarization directions.
- 5G antennas have special requirements for installation location.
- Since the 5G terminal antenna is a phased array system, its synthesized antenna units form a focused beam. Therefore, we need to place them in regular positions. Additionally, the antenna requires no metal to block it, making it suitable for 3D space scanning and regular space.
- When blocked by human hands or the human body, a 5G terminal signal will begin to search for the optimal bit error rate band. Figuratively speaking, the phone is like a little pet with eyes; once obstructed, its eyes immediately dart around to find the optimal channel. We call 5G mobile phone optimization. Therefore, when designing a terminal, the location of the antenna must be appropriate from the beginning to make it easy to optimize. In current mobile terminals, the most suitable positions for 5G antennas are at both ends, particularly the upper end (near the earpiece area). Other 4G internal antennas must yield to them, which means they have the priority for placement, while other antennas are relocated elsewhere.
- The 5G antenna is a module containing a chip.
- The antenna array consists of 16 small elements the size of rice grains; it is not feasible to use 16 shielded wires to route signals to the radio frequency chip. The challenge of connecting to the chip needs to be addressed on-site. We integrate the lead-out antenna with the lattice antenna into a single unit. Typically, a single chip manages four arrays.
- The output of the antenna module is not a radio frequency signal. You can use a connector to lead the terminal to the mobile phone motherboard.
