Qorvo helps you solve the antenna design problems caused by full-screen mobile phones

　　From Samsung S8, iPhone X to Xiaomi Max2, more and more flagship models choose full screen as the innovative design of the new generation of smartphones. Although the appearance design of the mobile phone has been greatly improved, it also brings huge difficulties and challenges to the antenna design . Let's learn about the relevant content with the mobile phone portable editor.

　　Recently, Locker Jiang, sales director of Qorvo  China's mobile product division, gave a detailed analysis and answer to this question at the "Jiwei Semiconductor Summit" held in Xiamen.

　　Why choose full screen as the innovation of the next generation of smartphones? Locker told Jiwei.com that how to make consumers feel the urge to change their phones is the top priority. On the one hand, the conversion from 16:9 to 18:9 screens is equivalent to the grip of a 5.9-inch smartphone being similar to the original 5.5-inch smartphone, and the feeling of holding it in one hand has become narrower. On the other hand, full screens also bring consumers a brand new experience in terms of appearance and vision, which is a new innovation for the smartphone market that tends to be homogenized.

　　Generally speaking, the antenna is around the outer frame of the mobile phone, with a main antenna on the top and a secondary antenna on the bottom. "The biggest impact on the performance of the antenna lies in how much space you leave for the antenna," Locker further explained, "If the antenna space is large, it will cover a better frequency band and have better efficiency, and its own performance will be better. However, the full screen squeezes the space of the antenna, and the result of squeezing makes the antenna efficiency worse, which ultimately affects the TRP (Total Radiated Power), which is the overall transmission power of the antenna." The TRP standard is set by the operator, and the frequency band has a specified value. You must achieve the specified TRP to pass the field test and meet the supplier's requirements, otherwise you can't do it.

　　For example, the previous 16:9 screen left 7-9 mm of clearance for the antenna, but now with an 18:9 screen, the space left for the antenna is only about 3-5 mm, or even narrower. Locker emphasized that this will test the process level of each antenna manufacturer, and they will strive to make the space left above and below the smartphone screen as narrow as possible, otherwise the loss of the antenna part will be relatively large.

　　In terms of frequency bands, the longer the antenna is, the lower the frequency band it can cover. In contrast, the high frequency band does not require a high size for the antenna. Therefore, once the antenna space is squeezed, the low frequency is the most affected, making the bandwidth narrower. From a numerical point of view, the TRP value is decreasing. When the screen changes from 16:9 to 18:9, the TRP numbers such as LTE B1, LTE B3, and LTE B5 actually do not meet the CMCC requirements and are lower than the CMCC requirements.

　　Judging from the demand for MIMO, 2CA, 3CA, 4CA, 5G, and low-frequency 600 MHz in smartphones, the number of antennas will continue to increase. If all the above functions are available, smartphones only need 2-4 antennas, but if they are replaced with full-screen ones, the number of antennas will increase to 4-7, and the number of antennas is also increasing.

　　Whether in terms of the number of antennas or the antenna space left, the biggest impact of the innovation of the next generation of smartphones is TRP. How to solve it?

Locker solves the antenna design problems 　　brought by the full screen from five major directions . The first is the open source method to increase the power of the PA. If the power of the PA is large, even if some of it is absorbed, more will be released in the end. The second is the ET or boost method, which increases the voltage to increase the power of the PA. He further pointed out that if the power of the entire circuit is increased, there are also special requirements for filters and duplexers, and they need to support higher power High Power Filters. There is also the use of Impedance Tuner (impedance tuning) and Aperture Tuner (antenna tuning) to help improve the efficiency of the antenna.

　　In fact, although the promotion of full-screen displays poses more challenges to Qorvo , an RF manufacturer, it also creates more opportunities. Locker pointed out that future smartphones will require higher-power PAs, additional ETs, higher-power filters, and more ACS tuners. The increasing number of RF front-end components is a boon to Qorvo . In addition, for Qorvo, a technologically advanced company, it is more willing to see the arrival of full-screen displays, seize market opportunities, and provide more and better solutions for smartphone manufacturers.

　　It is reported that the "Jiwei Semiconductor Summit" attracted more than 100 CEOs of the best semiconductor companies at home and abroad (the world's top semiconductor companies, well-known domestic IC companies, domestic mobile phone industry chain companies, and domestic first-class smart terminal companies), 50 government leaders/academicians/scholars/special guests, 50 mainstream semiconductor investment institutions, 150 securities analysts and 100 of the most influential mass financial and technology media at home and abroad.

　　The following is a transcript of a group interview with Locker Jiang, Sales Director of Qorvo China Mobile Products Division:

　　Reporter: You just mentioned the involvement of MIMO. Some of them are full-screen. In the future, you will need antennas on your mobile phones in this space. So after taking these measures, you will need to add PA, but will your volume change? Because this is related to your future MIMO deployment.

　　Locker: Volume, you mean.

　　Reporter: The chip power is increased, which means your PA power is increased. Then you take these measures. Does the chip size become larger or smaller? If it becomes larger, will it affect the deployment of MIMO?

　　Locker: My chip is not placed in the space below, but on the PCB board. In the end, it occupies the space of the antenna.

　　Reporter: Your chip is still placed on the board. If it is placed on the board, the board area will not be increased. Will this have an impact on the size for you?

　　Locker: A very good question. In fact, we see that the trend is that there are more and more integrated products. One of the great advantages of integrated products is the size. The volume will be smaller, that is, on the PCB board. Because there will be more and more frequency bands in the future, and there will be more and more LTE frequency bands, including 5G, and more frequency bands. In fact, you have to put all of them together. You see, all your CAs are now two CAs, and then three CAs and four CAs. In fact, there are indeed more and more frequency bands, and they are more complex, and there are more and more switches. After 4x4 MIMO, the RX part has more antennas, more filters, and more switches, which has always been a challenge in terms of size.

　　Our solution is, for example, to provide a receiving module, a diversity receiving module, in the RX part. We also have many PAMID forms on the main transmitter side, so we also see more and more flagship phones, especially the Xiaomi Max2, which uses a lot of PAMID, because it has to cover 43 frequency bands around the world. How many PAs and switches do you need in 43 frequency bands? This is really too large, so it finally chose to appear in a global form in order to respond to our doubts about how to reduce the size of the RF end. You raised a very good point, that is, there is a solution, that is, to provide various integrated solutions.

　　Reporter: You mentioned increasing PA, but the current didn't increase much. How did you increase the PA?

　　Locker: This is done through the ET method, which is to increase the voltage using the ET method.

　　Reporter: If the voltage is increased, does that mean there will be some requirements for the power of the entire mobile phone, and the power supply?

　　Locker: Yes, there will be some extra costs, and you need a DCDC, a bulk/boost, a step-up or step-down product. But for PA, the higher the input voltage, the higher the output power, and the current will not increase accordingly. If the input voltage is not high, and you have to push a very high power, the current consumption will definitely be greater.

　　Reporter: Do you need additional power supply for your full-screen design?

　　Locker: It is not a power supply, it is a DC-DC chip.

　　Reporter: So I need an additional DC-DC to support it?

　　Locker: Yes, if you want to do ET, you need to do it, but you don’t need to do ET. If you use ET, it is easier to implement, but you don’t need to do ET. It depends on how to tune it, and you can use many ACS tuners. There are various ways, and the final calculation cost depends on how to implement it best.

　　Reporter: Do you think that if the full screen leaves too little space for the antenna, will it be more difficult for the future, that is, for things after LTE or when it comes to 5G, when the system emphasizes smart antennas? In this regard, if, for example, in the future 5G, smart antennas or even multipath antennas are made, what impact will it have on the PA?

　　Locker: Yes, in terms of antennas, based on our cooperation with antenna manufacturers, we have seen that ACS tuner is indeed helpful, so this is the direction of cooperation between the two industries. How to improve the efficiency of antennas is definitely what antenna manufacturers have been considering. We are more concerned about how to enable mobile phone manufacturers to finally solve their problems under the current technical conditions of antennas. This is what we are considering.

　　Reporter: If the antenna technology is adjusted, what impact do you think it will have on the entire PA, or the RF signal chain?

　　Locker: Just now you looked at my picture. If the efficiency of the antenna is improved, the largest part is actually the part below, that is, the part absorbed by the antenna becomes smaller. In this case, the requirements for my PA will not be so high, but the problem is that it is still complicated when it comes to 5G, and there are still more requirements. This depends on how to calculate and the general direction. The link I just mentioned is like a seesaw, that is, one part is done well, and the other part is low. This is a seesaw. It is not necessary to do it well in every direction, as long as the final TRP meets the indicators. The final result is TRP. Every place here is a means to help it achieve.

　　Reporter: Will this be achieved by increasing power consumption?

　　Locker: Yes, if the ET method is not used, the current will be large.

　　Reporter: If the power consumption increases, this is something 5G does not want to see. Do we have the technology to reduce the power consumption of this communication module?

　　Locker: If you use ET, even if its power is high, the current is not that large.

　　Locker: If IoT is low power consumption, then it is low power consumption. But 5G is a very broad term. I think if you are in the range of millimeter wave, you can ask our engineers about the power consumption. Will the power consumption be greater in the case of millimeter wave?

　　Qorvo engineer: In fact, in 5G, low power consumption is not emphasized, but the speed bandwidth is emphasized. So from the perspective of our own devices, we will implement the technology in different ways. Through MIMO technology, the signal modulation method is made higher, and power is part of it. The power can be made better, and the coverage is wider and wider. 5G actually emphasizes high bandwidth and high coverage. As for the front end of the 5G, it will definitely bring power consumption problems. In fact, many of our manufacturers have begun to apply our ET technology. ET can actually save a lot of electricity. When we compare ET with existing technologies, the battery can be saved by about 20-30%. In fact, in the current market, many mobile phones are equipped with ET technology, and the power consumption is better. ET is the best means to solve power consumption. In addition, Locker mentioned that our integrated module products can bring lower insertion loss because they require high power but do not want the current to increase. That is to say, when there are fewer things behind you, the antenna outputs the same power, the PA power will be lower, and the current will also drop.

　　Reporter: I would like to ask another question. For millimeter waves, especially those with slightly higher frequencies, such as 20G and 60G, if these frequencies are used in 5G, will the PA equipment no longer be suitable for use in mobile phones? When mobile phones use 5G, they will still be in the frequency range of around 6 GHz?

　　Qorvo engineer: Because 30G power waves are also in the direction of 5G, they can definitely be applied to RF.

　　Reporter: But how long will your batteries last?

　　Qorvo engineer: We don't have any specific data to look at, because what we have seen in recent years are less than 6G. This year we have seen the research direction of 5G. We basically divide 5G into two parts: less than 6G to millimeter wave. Recently, we have seen that the products launched are all below 6G.

　　Locker: We don’t have specific data yet, but my understanding is that millimeter wave is mainly used for short-distance transmission, and its power consumption should not be particularly large.

　　Locker: Yes, in fact, there are basically four RF front-end suppliers now, Broadcom, Skyworks, Qorvo and Murata, and they are all equally matched, each with their own strengths and technical features. I don't think anyone is leading the way. We can only say that everyone has some directions, such as making integrated products. For Qorvo, our technical feature is that our products are relatively wide, that is, the product technology we apply in the RF front end is relatively wide. We have PA, everyone has PA, but we now have a new process PA of HBT5. Do we have filters? Everyone has filters, but in addition to SAW filters, we have BAW filters, which Avago and TDK just mentioned have, but some do not. Then we have switch technology. All switch technologies are now available to everyone, but Qorvo's switch technology is the most advanced, because first of all, its market share is the largest, and we have more than 70% market share in the antenna tuning market. In fact, especially for switch products, PA is more about the process and filter. Our BAW and SAW filters are also based on the process of one generation after another. Only when the process is good can you make the product well. Switches are very interesting. All switches are outsourced, basically made by outsiders. None of our companies produces switches by themselves. But we are innovative. How do you define some products? Can you come up with some good products earlier than our peers and then guide the market? This is what Qorvo does very well in the switch field. And we have a very full range of products, many of which are actually targeted at some special applications of customers. We won an innovation award from vivo this year. Our innovation ability is very strong, that is, we can provide customers with many good product ideas. I think this is our strong point.

　　So we are all running forward. We cannot say that I am running faster than others today. Everyone is running forward. For a period of time, I may run a little ahead, so I can get a little more market share. For a period of time, our competitors run ahead and they get more market share, but overall, everyone is developing in a healthy way. I think this is very good. I don't know if this answer can be considered as answering your question.

　　Reporter: What strategies or means will Qorvo have for the Chinese market this year or in the next few years to help some local Chinese mobile phone manufacturers to improve their RF performance? What kind of support will it provide?

　　Locker: Actually, we are very close to our customers, because the whole team has a lot of people. The good thing is that we have several major customers in China now, all of which are very famous. In fact, we have a very good relationship with them, and they are all important partners. So the main thing is that we are actually following very closely. We are following the technology trend. For example, the full screen issue, we are providing our solutions to help them solve their problems. This is what we have been doing and what we will do in the future. Including our discussion of 5G, including our IoT, we also have a very good solution for IoT. Of course, this has nothing to do with mobile phones, it is another field of our company. In the mobile phone area, the most important thing is that the trend we see now is high-power PA, including high-power filters. This is what we see customers have this requirement. In fact, this requirement has been put forward, and this is a clear direction. For example, ACS tuner, I just mentioned these, in fact, this is exactly the requirement raised by our important customers now and next year. Of course, there is also our PAMID, integrated products, which is another series of products.

　　So generally speaking, there are the three technical parts that I just mentioned, PA, filter, and switch, and the product form is this integrated module. The integrated module will still have some evolution, so we can talk about it again in the future if we have the chance.

　　Reporter: What do you think, looking at the picture above, including the third one on the picture, which is cars, because cars are now autonomous, unmanned, or connected to the Internet, there is actually a huge demand for PAs?

　　Locker：Yes.

　　Reporter: In this regard, are the requirements of PA different from those of mobile phones?

　　Locker: The Internet of Vehicles now uses more 4G modules, which may have higher requirements for security and reliability.

　　Reporter: Is there no difference in transmission?

　　Locker: There is no difference, it is the same.

　　Reporter: I would like to ask another question about mobile phones. In addition to full screens, as the reporter just said, the power consumption of mobile phones is also a very embarrassing problem. There is a trend that everyone wants full screens to be bigger and smaller, but there are another group of people who want to return to the old 2G feature phones, saying that I can use a mobile phone for two or three days, and it can be guaranteed, especially I don’t need so many dazzling screens and so many entertainment applications, but I can hope that it can guarantee three or four days of standby and stability. So for the PA system in this regard, how do you think this problem can be solved to ensure that the entire communication system works better, more efficiently and more power-saving.

　　Locker: I have just said that ET is a very good way. Through ET, your basic needs are met, such as 4G, for example, you have more CA, unless you go back to 2G, which is impossible. If we move forward, then ET is a balance, and PAMI, because our insertion loss is better, so the whole link will be lower, so the overall power consumption, current will be lower, and power consumption will be smaller.

　　Reporter: So what do you think about the future? These two different trends and different demands will require you to use different products or come up with different solutions to meet them.

　　Locker: Different solutions can be used to meet the needs. As for products, solutions are a better way to solve a problem that takes both ends into consideration.

　　Reporter: But in your proposal, how do you view the cost of modularization, and how does it compare with its flexibility and differences?

　　Locker: This depends on the final cost. If we look at it now, flagship phones can bear more cost pressure, so they will consider using modular products. If there are fewer frequency bands, entry-level or mid-to-low-end phones do not need so many frequency bands, so they will choose a more separate approach.

　　Reporter: What do you think about the PA materials? As we just mentioned, in the short term, GaAs is still used for PA materials, but GaAs materials are constantly being updated and replaced. So, what do you think about Qorvo, as we know that Qorvo used to develop these materials by itself and also cooperate with external parties, if the R&D costs become more and more expensive in the future, how will Qorvo spread these R&D costs?

　　Locker: Our factory has a large production capacity. In fact, it is more about updating the process. At present, it is all HBT. We have the fourth and fifth generation products, which take into account power output and current consumption. In the future, there may be HBT6. In fact, this power update is to take both ends into consideration and do better. This kind of raw material is a very challenging problem. I just want to say that the update of process is our direction and has always been our direction.

　　Reporter: You mentioned the process update, that is, what do you think about the prospect of FDSOI RF?

　　Locker: We use SOI a lot now. SOI is used in switches. We also had such products as CMOS before. We are pursuing two paths. In fact, we are also continuing to develop CMOS, but we are targeting more CMOS markets with lower costs. We will serve such markets, but if we hope to have a market with better performance, we will still focus on GaAs.

　　Reporter: Mobile phones now have glass back covers, which is good for radio frequency. Metal used to be bad for antennas, and there is also ceramic.

　　Locker: Yes.

　　Reporter: But now if we talk about the original metal problem, the antenna is engraved on the back. If it comes to 5G or 6G, will it still be like this, that is, it has a middle frame engraved on it?

　　Locker: Of course 5G is possible. It is also possible to make the antenna on the back cover, and then I just sell PA. It is possible to bundle the function module. This is possible.

    The above is an introduction about how Qorvo solves the problems of antenna design caused by full-screen mobile phones in portability. If you want to know more related information, please pay more attention to eeworld. eeworld Electronic Engineering will provide you with more complete, detailed and updated information.