PCB News - 4G and 5G base station structure and 5G PCB usage

The basic principles of 3G, 4G and 5G base stations are similar, but there are some differences in specific designs. 4G base station equipment is mainly composed of three parts: baseband processing unit (BBU), remote radio frequency processing unit (RRU) and antenna system. At present, in 4G communication base stations, the antenna system and RU should adopt high frequency PCB and high speed PCB, and BU mainly adopts high speed PCB.
Baseband processing unit BBU: completes functions such as channel encoding and decoding, baseband signal modulation and demodulation, protocol processing, and provides the functions of upper-layer network unit.
Processing unit RRU: It is the intermediate bridge between the antenna system and the baseband processing unit: When receiving the signal, the RRU uses filtering, low-noise amplification and converts it into an optical signal, and converts it into an optical signal; When sending to the BBU, the RRU converts the optical signal from the BBU into a radio frequency signal and amplifies and sends it through the antenna.
Antenna system: It mainly performs signal reception and transmission, and is the information energy converter between base station equipment and end users.
From 4G to 5G, there is no essential change in the attractiveness of base station structure and basic materials, but the dose and parameters are greatly improved. Therefore, the study of 4G base station structure and the application of high-frequency PCB has certain reference significance for 5G.
Antenna, as a device for energy conversion, directional radiation and reception, is the core of the entire base station operation. It is mainly composed of five core components (4G base station antenna): radiation unit, feeder network, reflector, packaging platform and antenna controller (RCU) composition.

(2) Calculation of PCB consumption of 4G base station
The PCB used in 4G base stations is mainly divided into antenna system RRU and BBU. According to one BBU towing three pairs of antennas and three pairs of RRUs, the total area of the antenna system PCB is about 0.684 square meters, and the total area of the antenna system PCB is about 0.3 meters. The total area is 0.984 square meters.

According to industry research information, the average price of 4G antenna and RRU PCB is about 2500 yuan/square meter. As for the single base station RRU and antenna part, the ASP is about 2500 yuan. BBU part, the size is about 440X86X310mm

The number of BBU boards is between 3 and 6, and each board is connected to the backplane through an interface. The slot distribution and board configuration principles of the BBU boards in the BBU are as follows: GTMU occupies 5 and 6 channels and is the main control transmission Unit, the remaining plug-in boards can be installed with the TDL base board and the main control board, the base board can realize the interface function, and the received CPRI data can be forwarded to other single boards.
The total area of the main control board, star card board, baseband processing board and baseband radio frequency interface board is about 0.3 square meters, the power board is about 0.03 square meters, the surge board is about 0.008 square meters, and the total value of a single station is about 992 yuan.

For CCL, in 4G base stations, the high frequency PCBCCL required for antennas and power amplifiers is less than 5G. Hydrocarbon or polytetrafluoroethylene materials are generally used, and most of them are pressed together with ordinary FR4. high speed PCB CCL is mainly used in other fields such as BBU, and its material can be modified with FR4. In general, high-frequency and high-speed CCL accounts for about 20% of the PCB value of base stations, which is equivalent to about 102 billion yuan in global market space for one year.

(3) The pace of technological change and evolution brought about by 5G
As of January 2019, GSA has 201 operators in 83 countries, including 5G commercial testing, pre-commercial and commercial operations. Especially in the United States, South Korea, Japan, the United Kingdom, China and other regions, they are the first countries to carry out 5G commercial construction, and they will achieve 5G commercial network construction in 2019-2020.
China's three major operators have launched 5G commercial tests in five major cities. China Mobile plans to install 1,000 5G base stations in 2019, and then conduct commercial tests nationwide in 2020.

Technically, other manufacturers actively participate in the research and development of 5G baseband chips and terminals to promote the maturity of the 5G industry chain.
In terms of chips, Qualcomm (Qualcomm) and Samsung (Samsung) released 5G commercial chips at the end of 2018. Mediak will also launch its own 5G baseband chip in 2019.
The maturity period of mobile terminals is relatively long. 5G mobile phones and independent baseband chips based on the 7-10 nm process are expected to be available in 2099. 5G mobile phones based on the SOC multi-mode chip platform are expected to be commercialized in the second half of 2020. In the future, with the development of terminals, products using the latest RF front-end technology, such as small wearable 5G terminals and full-band 5G mobile phones, are expected to mature in 2021.

The PCB value of the 5G macro base station is about 15104 yuan/station, the PCB value of the indoor substation is about 30% and 40% of the macro station, the PCB value of the 5G macro base station is about 5286 yuan/station, and the PCB value of the 5G macro base station It is 3.2 times of 4G (4,692 yuan), and there is more room for promotion.
Taking into account the progress of 5G construction, assuming the layout rhythm of macro base stations and indoor substations from 2018 to 2022, the construction of 5G base stations can bring incremental market space for PCBs within one year (assuming that the value of single-site PCB&CCL decreases by 6% per year ).
It can be seen that in the peak period of 2022/2023, the single-year PCB demand brought by the construction of 5G base stations is about 210 billion to 24 billion yuan (of which mainland China accounts for about 50%-60%), almost in the 4G era Three times the 8 billion yuan.
The communication PCB market is generally fragmented, but the demand and pattern of high-end rails are good. The global communications market is about 12 billion U.S. dollars, and the top five companies only account for about 20%, but in fact, the main participants of PCBs (or high-frequency materials) with 18 layers or more are the first echelon. In the process of storage device upgrades caused by communication generation changes and data flow explosions, when the trend shifts upwards to the PCB link, the increase in its value and usage is often based on high-level quantities, new materials and new process PCB products. However, low-level PCBs (mainly used in some secondary links or low-end equipment) have less flexibility in demand changes than high-level PCBs, and Tier 1 manufacturers are the main manufacturers that benefit from value and consumption growth. It has a moat in terms of technical barriers, fixed asset investment barriers, commercial barriers, and certification jet lag barriers.