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5g millimeter wave technology and base station solution

Release date:2021-12-28Author source:KinghelmViews:223

Since five years ago, the network has gradually transitioned from 4G network to 5g network. One of the most obvious changes is the increase of network frequency. In the 4G era, we mainly use frequencies of 2.6GHz and below. In the 5g era, the frequency band has been extended to sub 6GHz. The arrival of millimeter wave has increased the network frequency to higher frequencies such as 28ghz and 39ghz.


In the 5g era, another obvious change is the increase of bandwidth. In the 4G era, the network bandwidth is 2 & times; 20MHz. In the 5g era, the bandwidth has been greatly improved. For example, the bandwidth of 3.5GHz network has reached 200MHz, and some OEM manufacturers have brought 300MHz and 500MHz bandwidth. The introduction of millimeter wave can expand the network bandwidth to 2GHz.

In this case, the improvement of the full page efficiency of the base station is also an important concern.

"To achieve the designer's goal, it involves the performance improvement of key devices such as Pa. in the 4G era, we basically use LDMOS PA in the base station, while in the 5g era, we all focus on GaN PA with higher applicable frequency band and better efficiency." Said Jenny Xun, engineer manager of qorvo wireless infrastructure division. She further pointed out that in terms of product form, 5g base stations have undergone unprecedented changes compared with similar products of previous networks. In the 4G era, the layout of base stations is dominated by the configuration of macro base stations and micro base stations. However, in the 5g era, the forms of base stations are more diversified. Sub 6G MIMO, indoor small base stations and mmwave base stations will play an important role, which also brings opportunities to manufacturers.


"The change of antenna array is another obvious change of 5g. In the 4G era, the base station uses 8 & times; 8 array at most, but in 5g, the array is expanded to 32 & times; 32, or even 64 & times; 64. The antenna array in some millimeter wave application scenarios is higher." Jenny said.

Behind these technological changes is the growth of relevant market demand.

As shown in the figure above, 5g brings various demands, among which the shipment of millimeter wave Ru will increase significantly. The figure below shows us the detailed performance of this market.

Geographically, before 2025, it will mainly focus on the North American market, which has a very important relationship with the commercial 5g millimeter wave in the United States. After 2025, we can see that with the increased investment of China, Japan and South Korea, the Asia Pacific region will usher in the outbreak of 5g millimeter wave Ru. The following figure also shows the development trend of 5g millimeter wave Ru from two different angles of power and architecture.


Jenny pointed out at the meeting that according to the requirements of transmission power and scanning angle, we can divide 5g millimeter wave applications into the following categories: one is a high-power urban macro base station, which has high requirements for EIRP, up to 65dbm. It also has strict requirements for vertical and horizontal scanning angles; Another use case is the high-power macro base station for rural areas. This use case also has high-power EIRP (65dbm), but in this use case, the scanning requirements for vertical aspects are not so high; The third is the low-power outdoor macro base station, whose EIRP demand is only 45dbm; In addition, there are also indoor small base stations and repeaters. The demand range of this use case for EIRP is 45dbm to 52dbm.


"We can predict that network coverage will always lead the capacity demand. Therefore, we need to solve the demand for 5g millimeter wave signal coverage before we can usher in the improvement of market capacity." Jenny said.

Jenny further said that from the figure below, we can see the hybrid networking form of sub-6ghz and millimeter wave. Among them, sub-6ghz network is used to ensure network coverage and basic connection, so that people can get 5g signal wherever they go. The millimeter wave band with frequency greater than 6GHz is used to meet the application scenarios with high throughput, such as stadiums, large shopping malls and airports.


"In the face of 5g's diversified network demand, qorvo's diversified product layout can provide developers with all-round support," Jenny said. From her introduction, we know that, first of all, qorvo can provide a variety of processes including GaAs, Gan, BAW, tc-saw, SOI, SiGe and CMOS, and can manufacture various RF devices that meet the needs of 5g band; In terms of packaging, qorvo also has plastic packaging, cavity and other packaging technologies to meet the different packaging needs of various devices.

Next, we take the challenge of 5g to PA design as an example to illustrate qorvo's strength in the RF field.

As shown in the figure below, with the evolution of the network, the signal bandwidth is greatly improved, which puts forward higher requirements for the linearity of PA. In this process, par is also increasing synchronously. In this case, it is necessary to ensure the efficiency of signal fallback, which also puts forward higher requirements for the efficiency of PA. In addition, due to the requirements of carrier aggregation, thermal power consumption and size, 5g brings unprecedented new challenges to PA design.

"To this end, we not only require PA to have higher efficiency and frequency, but also require greater video bandwidth and better broadband linearization technology. In this scenario, Gan PA can play an important role," Jenny said.


As shown in the figure above, operators want to have lower operating costs, lower capital expenditure, higher reliability and higher data throughput in practical work, which is what Gan solution has. From the figure below, we can see the requirements of base stations for different processes in different scenarios. As an industry expert, qorvo can provide comprehensive technical coverage to help customers solve relevant problems. From this figure, we can also see the significance of Gan PA in 5g era.


Readers familiar with Gan should know that current gallium nitride devices have different substrates. Among them, qorvo's SiC Based GaN has great value in PA applications, including high efficiency, high bandwidth and helping to build small-size devices. This is mainly related to the lower parasitic capacitance, lower RF loss, higher breakdown voltage and better thermal conductivity of SiC Based Gan. Qorvo's Gan device can better reflect the above Gan advantages. Qorvo can also provide different schemes for selection according to the requirements of different application scenarios, as can be seen from the figure below.


"Based on these technical layouts, qorvo can provide customers with various products covering multiple frequency bands, including FEM, PA, switch and LNA. In addition, the integration scheme with better technology is also a direction for qorvo. These schemes have unique advantages in cost and power consumption, and can also help customers put their products into the market faster, which is exactly what customers need Yes, "Jenny pointed out at the meeting.


From the development process, qorvo's PA has evolved many times. What is the driving force behind its progress? When talking about this, Jenny said that this is mainly related to the company's consistent adherence to the goal of pa - that is, the company's PA can have high power and efficiency, use smaller arrays to achieve high EIRP, and then bring greater coverage. Therefore, the realization of smaller array size and smaller overall board power consumption is the focus of qorvo's product research and development.

"Having high output power and high efficiency is our most fundamental requirement for pa", Jenny stressed. From the comparison of the following two figures, we have a clearer understanding of the advantages of qorvo products.

From the above introduction, we can conclude that GaN has incomparable advantages over other materials in RF applications. Through the comparison of different materials, we can more clearly see the leadership of this material.

As a leading supplier of RF system solutions, qorvo provides leading RF device products such as PA, FEM and LNA for 5g millimeter wave demand. Qorvo can also provide different solutions for different application scenarios.