Chapter 251 Gallium Nitride Active Phased Array Radar [Subscription Request]

"This is our preliminary design for the laser system. Professor Xu, please take a look at it first."

"If there is anything inappropriate, please speak up."

2015 6 Month 17 Day.

Wednesday.

As the Dragon Boat Festival was approaching, Xu Yuan was invited by Professor Zhao Xiang to the research laboratory of Qinghua Institute of Physics.

Participated in the laser system development meeting for steady-state micro-bunching and testing experiments.

In the past three months, Xu Yuan and Zhao Xiang have thoroughly completed the theoretical analysis and physical design of the experiment.

We only need to solve the design of the laser system for the test experiment before we can officially use the storage ring and complete the verification of the working mechanism of steady-state microbunching.

Only then can we prove our concept.

And further explore its value and build our own high-energy synchrotron radiation light source in China.

This saves us from having to go overseas and borrow other people’s storage rings to conduct research in this area.

To verify the steady-state microbunching, the research team needed to use a laser with a special wavelength to manipulate the electron beam in the storage ring so that the electron beam would form a fine microstructure after a full circle around the ring, i.e., microbunching. Microbunching will radiate high-intensity, narrow-bandwidth coherent light at the laser wavelength and its higher harmonics.

The experiment verifies the formation of microbunches by detecting this radiation.

Therefore, the design of the laser system is very important, which is the prerequisite for the successful verification of steady-state micro-bunching.

In addition to Zhao Xiang and Xu Yuan, there were several doctoral students standing at the scene, all of whom were students taught by Zhao Xiang.

They are here not because they can help the project, but mainly because they don't want the opportunity to learn.

Through communication and discussions with Xu Yuan over the past few months, Zhao Xiang has become very impressed by Xu Yuan's level of high-energy physics.

Sometimes, I even feel inferior to myself.

Especially some thoughts.

I have been researching in the field of high-energy physics for half my life.

He also frequently visited overseas to absorb advanced overseas experience, but his understanding of some issues was still not as good as Xu Yuan's.

If Xu Yuan's area of ​​expertise was high-energy physics, that would be fine and could be regarded as the difference between a genius and an ordinary person. The key is that Xu Yuan is good at mathematics.

So thinking about what he was going to discuss today, he specially called his students over.

I just happened to be able to listen to Xu Yuan’s explanation.

Improve your own awareness.

Good to have a deeper understanding of physics.

When Xu Yuan just came in, he noticed these students, and several pairs of eyes were staring at him.

Didn't divert his gaze at all.

It seems that he is afraid of not paying attention and accidentally missing something important.

Of course he didn't say much.

At present, I have not supervised any graduate students or doctoral students in school, but I sometimes provide guidance to students on their thesis.

He would be happy if someone could really learn something from him.

In the following time, Xu Yuan no longer hesitated and took the design plan to look at it carefully.

At this time, the entire laboratory seemed very quiet.

A few doctoral students in particular didn't dare to make a sound, for fear of disturbing Xu Yuan.

They know very well how precious today's opportunity is.

If it weren't for the mentor's help, it would not be so easy to sit here.

Everyone knows Xu Yuan's current fame. At the age of only 30, he has achieved academic results in many disciplines that are beyond the reach of others. Even many professors hope to communicate and discuss with Xu Yuan.

Xu Yuan naturally had no idea what the people at the scene were thinking, and he didn't care at all.

Even if there is any noise, it won't affect him.

His eyes fell on the design plan and he was quickly immersed in it, his attention becoming highly focused.

Enter the deep learning state.

The whole person's perception has long been disconnected from the outside world, and it seems that only the design plan is left in his sight.

Zhao Xiang noticed Xu Yuan's serious attitude and felt quite envious.

It is very difficult to calm down so quickly, even if you train yourself.

Only outstanding talent can do this.

It has to be said that Zhao Xiang deserves credit for proposing the steady-state micro-bunching, and his work in laser system design is truly impeccable.

They are basically in line with relevant experimental verification concepts.

Finally, when it comes to wavelength, Xu Yuan organized his words a little, looked away, and expressed his opinion.

"There is no problem with this laser system design."

"Especially Professor Zhao, you are familiar with the Berlin Storage Ring and can design it in conjunction with the storage ring."

"In order to make the verification experiment go more smoothly."

"I have some more suitable ideas about laser wavelength."

“You can keep the wavelength at the optimal nanometer length.”

Zhao Xiang listened to everything Xu Yuan said and was secretly happy that Xu Yuan approved of this design plan.

At the same time, after learning about the laser wavelength issue, an expression of anticipation appeared on his face.

He quickly signaled, "Professor Xu, just go ahead. We can discuss this now."

As soon as he finished speaking, he turned his head to look at the doctoral students and gave them some special instructions.

"You all need to listen carefully to Professor Xu's guidance. Others don't have this opportunity."

“Don’t worry, advisor. We will definitely listen carefully,” the doctoral students said in unison.

"Don't be so serious, just treat it as a normal discussion." Xu Yuan quickly waved his hand when he heard that.

Without any further delay, he immediately expressed his ideas based on Zhao Xiang's design plan.

Zhao Xiang's face was full of seriousness, and his eyes became brighter and brighter after listening.

Obviously, he also realized the value of Xu Yuan's method.

Later, he took the initiative to participate in the discussion and had more detailed exchanges with Xu Yuan.

In the end, this laser system design discussion meeting lasted nearly three hours.

It ended just before lunch.

But the gains were also great.

Zhao Xiang not only optimized the laser system design plan, but also had more confidence in the subsequent practical verification.

……

In the following period, Zhao Xiang's research team was also very efficient. After completing the laser system, they began to connect with Berlin.

Prepare to conduct verification experiments.

Although this process will not be quick, it also involves docking with the storage ring.

But in Zhao Xiang's opinion, it is already very fast. It is possible to turn the concept into technology in just a few months, which is simply impossible in his previous projects.

Zhao Xiang attributed the credit to Xu Yuan.

After all, if it weren't for Xu Yuan's help, the experiment might not have progressed so smoothly.

It turned out that Mr. Yang had a good vision and recommended a very suitable assistant to him.

It is worth mentioning that using overseas storage rings is definitely different from using one's own.

We need to take care of the other party's scientific research time and projects. Many times, even if we are ready, we still have to waste time and wait patiently.

Only when the storage ring is idle can Zhao Xiang and his team verify the concept of steady-state microbunching.

If nothing unexpected happens, this process may require multiple trips back and forth between the two places.

Therefore, Xu Yuan did not participate in the specific verification process.

Zhao Xiang will be fully responsible.

Anyway, the progress bar on the panel is there, and the concept of steady-state micro-bunching has been successfully verified.

It's a done deal.

What we should consider most is how to further develop the value of this technology.

that's it.

When the end of the month came, Zhao Xiang's research team went to Berlin to start the experiment for the first time.

As for Xu Yuanren, he lives in Jinling City.

Since the last successful maiden flight of the stealth unmanned bomber, it has demonstrated excellent stealth performance, making it impossible for even the most advanced ground radar modules in the country to detect it at short distances.

This was a big blow to the ground radar research team led by Academician Zhang Guangyi.

The main project they are responsible for is the ground radar module, which can be quickly deployed with the help of a radar vehicle.

During wartime, it is responsible for detecting enemy aircraft and ensuring safety within the range.

Therefore, in their eyes, it doesn’t matter how good the stealth performance of domestically made stealth aircraft is. In short, as long as it passes through the range of ground radar, it must be detected and discovered in time.

If this cannot be done, it does not mean that the aircraft's stealth performance is excellent.

Rather, their ground radar vehicles are not advanced enough.

Only such high standards and strict requirements can ensure the powerful performance of ground radar.

Take the domestically-produced stealth unmanned bomber that just successfully completed its maiden flight.

In terms of its stealth performance alone, it may rank first in the world, but the overseas Ghost strategic stealth bomber should not be underestimated.

Its radar reflection area is also only 0.01 square meters, just like a sparrow in the sky.

More powerful and advanced ground radars must be developed to ensure that ghosts have nowhere to hide.

To this end, Zhang Guangyi and his team have been looking for ways to improve the performance of ground radar in recent times.

Although the direction has been successfully clarified, there are still some problems that cannot be solved for the time being.

In this situation, Zhang Guangyi thought of Xu Yuan, so he specially sent him an invitation.

I hope to seek Xu Yuan's help.

After all, everyone knows that it was Xu Yuan who designed the active phased array radar for the J-20, which brought new breakthroughs in domestic radar technology.

When Xu Yuan received the news from Zhang Guangyi, Zhao Xiang was just about to set out to conduct an experiment to verify it.

Thinking that he had nothing important to do, he agreed.

He attaches great importance to the research on domestic radar, which has high strategic significance.

If ground-based radars become more advanced, they can be used on airborne active phased array radars, allowing aircraft radar detection range to be longer.

In this way, when facing enemy aircraft, the advantage will be more obvious.

For example, if the radar of the most advanced fifth-generation stealth fighter in the country is further strengthened to the original level, the combat effectiveness it can exert will surely achieve a global lead.

Far exceeds other fighter models overseas.

So, accompanied by his full-time driver Wang Fei, Xu Yuan arrived in Jinling City smoothly.

And go directly to the 14th Institute.

As an important research institute under the Electronic Technology Group, it is mainly engaged in research in the fields of microwave communications and computers.

It is the birthplace of the domestic radar industry and the founder of many new high-end radar equipment.

When Xu Yuan arrived at his destination and just got out of the car, he saw an acquaintance coming to greet him.

Standing at the top was Academician Zhang Guangyi.

"Xiao Xu, you are finally here. We are all looking forward to your visit." Zhang Guangyi had obviously not had much contact with Xu Yuan, but at this moment he was very enthusiastic, as if he had met a relative. He took the initiative to extend his hand and shook hands with Xu Yuan with a smile on his face.

Xu Yuan also hurriedly replied:

"If you, Academician Zhang, ask me to, I will definitely come here as soon as possible. I just hope I can be of help."

"You don't need to be modest when it comes to radar. Even if you look around the world, I'm afraid you won't find many people better than you." Zhang Guangyi said with a smile, not hiding his recognition and praise for Xu Yuan at all.

And what he said was indeed correct, as Xu Yuan designed the active phased array radar alone.

It has already surpassed the radar technology level in many parts of the world.

At this moment, Zhang Guangyi suddenly thought of something and told Xu Yuan something excitedly.

"correct."

"I almost forgot to congratulate you. Wait a few months and our Academy of Engineering will have another young academician."

"I didn't even dare to think about being an academician at the age of 30."

Xu Yuan listened to everything Zhang Guangyi said, but did not seem too surprised.

The expression on his face remained basically calm.

The main thing was that he knew what Zhang Guangyi was talking about and knew that he was talking about the preliminary approval of his nomination for academician.

Submit nomination materials every year in accordance with the relevant procedures for the election of academicians.

From May to July, a preliminary review committee will be formed by experts from the Academy of Sciences or the Academy of Engineering.

Responsible for evaluating nomination materials.

Eligible candidates are screened out based on their academic level and influence indicators.

Then it enters the next stage of expert review.

At present, not only has his nomination to the Academy of Engineering passed the preliminary review, but the same has been true for the Academy of Sciences.

In other words, after the final review from August to October, the list of new academicians will be officially announced.

Given his conditions in all aspects, it is naturally a sure thing.

Zhang Guangyi was obviously aware of the situation, so he chose to congratulate in advance.

At this time, Xu Yuan remained humble and did not put on airs just because he was about to become an academician.

The next second, he said with a warm smile on his face: "Whether I am an academician or not, it will not affect my devotion to the cause I love." This made Zhang Guangyi smile even more.

When the content of their conversation reached the ears of several researchers from the Fourteenth Institute nearby.

I was also extremely envious of Xu Yuan.

no way.

Looking at the many full professors across the country, how many of them can be selected as academicians and become first-level full professors?

The vast majority of professors remain at the level of full professor II throughout their lives.

It is very difficult to become an academician.

All conditions must be met.

Otherwise don’t even think about it.

But since Xu Yuan graduated with a doctorate, at the age of 30, he is expected to be selected as an academician.

How can we not envy such speed?

However, although everyone was envious, no one expressed dissatisfaction.

Even question.

Very simple.

Xu Yuan's academic achievements are all there, and any one of them taken individually would leave many professors far behind.

What's more, it's all concentrated on one person.

Compared with Xu Yuan's own talent, they all felt ashamed of themselves.

How can I have the nerve to question it?

After all, if they could achieve Xu Yuan's achievements, they would have been academicians long ago.

"It's good that young people have this mentality." Zhang Guangyi nodded with a look of satisfaction on his face when he heard this.

He did not mention the business afterwards, but instead showed concern for Xu Yuan.

"You've come all the way from Yanjing, so you should go and rest first. We can talk about the project tomorrow."

"Anyway, we have to stay a few more days this time."

Zhang Guangyi has devoted all his energy to the research of ground radar modules. In the past few days, he seemed to have determined the direction, but was delayed by a small trouble. He was so anxious that he wanted to curse.

When I saw Xu Yuan coming, I couldn't wait to discuss with him.

But in the end, I endured it temporarily.

After all, Xu Yuan was the person he invited to help. It was indeed a bit inappropriate for him to get involved in the work after just traveling a long way.

When Xu Yuan completed the test of the stealth unmanned bomber, he had a discussion with Academician Zhang Guangyi about the active phased array radar, and it can be said that he was very clear about the other party's mood at the moment.

Plus, he didn't feel tired, so he just smiled and said:

"Academician Zhang."

"Let's get down to business. I'm also curious about the progress of your ground radar research."

"Is it convenient now?"

Zhang Guangyi was already impatient, and now when he heard Xu Yuan say this on his own initiative, he would not delay any further.

A bright smile appeared on his face, and he responded excitedly.

"Of course it's convenient. I'll take you there and I can explain it to you in detail on the way."

As soon as he finished speaking, he immediately set off and walked in front to lead the way. The whole process was very smooth.

Seeing this, Xu Yuan naturally followed closely behind and listened carefully to Zhang Guangyi's explanation of the project.

"I think the idea you gave last time is correct. Currently, active phased array radar is the best choice."

"It is definitely impossible to reproduce the performance improvement from passive phased array radar to active phased array radar."

Listening to Zhang Guangyi's words, although Xu Yuan did not speak, he nodded frequently.

I felt relieved that Zhang Guangyi could think of this.

The radar is transformed into an active phased array radar through technological upgrades based on the passive phased array radar.

As a result, the radar performance and detection range have shown a clear upward trend.

So that radar research has entered a new field.

However, it is impossible to replicate this upgrade in the radar field at this stage.

After all, the research on active phased array radar is relatively mature nowadays.

The thought stays here.

Xu Yuan was also quite curious about Zhang Guangyi and their solution.

Fortunately, Zhang Guangyi did not keep the matter in suspense and continued to tell the story the next second.

"After determining this central idea, we set our sights on semiconductor materials."

"We wanted to further improve the radar's power performance by replacing its semiconductor material. After extensive research, the project team found that gallium nitride is a very suitable material."

“The use of gallium nitride semiconductor materials, with its own high electron mobility and saturation electron velocity, enables the T/R module to generate higher RF power.”

“Thereby improving the radar’s detection range and anti-interference capabilities.”

"In addition, gallium nitride devices have lower losses, which ensures higher energy conversion efficiency."

"This allows the radar to produce a stronger signal at the same power."

“It reduces energy consumption while using the same amount of power.”

"The most critical thing is its wide bandwidth effect. Gallium nitride devices can operate in a wider frequency range, which makes the radar system more flexible and adaptable."

It can be seen that Zhang Guangyi and his colleagues' research has indeed made significant progress.

When talking about these advantages, he was visibly excited.

Xu Yuan has been exposed to and participated in material research since he was a child, and he also has some understanding of gallium nitride semiconductor materials.

Know that this is a wide bandgap semiconductor material.

It has high electron mobility, high saturated electron velocity, high thermal conductivity and good chemical stability.

Judging from these advantages alone, GaN technology is indeed particularly suitable for radar systems.

It can significantly improve the radar's transmission power and efficiency.

If it is true as Zhang Guangyi said, China has successfully developed this gallium nitride active phased array radar.

Then domestic radar technology will firmly occupy the world's leading position.

And it's a crushing lead.

In this way, even the most advanced Ghost stealth bomber overseas will be restricted by the existence of gallium nitride active phased array radar.

The comprehensive performance it can bring out is affected.

However, gallium nitride technology is not yet mature. I think Zhang Guangyi’s team must have encountered this problem, which led to the suspension of research.

Otherwise, the other party would not have specially invited him to come and help.

After thinking this through, Xu Yuan took over the conversation as he followed the other party forward.

"The characteristics of gallium nitride semiconductor materials can indeed play a very good additive effect on the current active phased array radar."

"But there are still technical flaws in gallium nitride."

"I wonder what problems you encountered, Academician Zhang?"

"I knew it was right to ask you to come and help. There are indeed still problems with GaN technology." Zhang Guangyi quickly replied: "In addition to the high production cost and complex process of GaN devices, which increase the cost and production cycle of active phased array radar systems, the reliability of GaN devices under high temperature and high power conditions still needs to be verified."

At present, domestic active phased array radars have matured and the cost of their core modules has been controlled.

It can even complete production in a shorter period of time and can be equipped on a large scale in various fields.

By using gallium nitride technology, the cost and production cycle of radar systems will be greatly improved.

Unless the gallium nitride technology can be optimized to reduce the cost and cycle.

Another thing is that when the radar system is in operation, it will generate high power and high temperature for a long time.

In this environment, if GaN devices cannot maintain stability.

That's definitely not usable.

After all, whether it is ground radar or aircraft, if the radar suddenly has problems during use, the consequences may be serious.

There is simply no way to afford it.

Therefore, if Zhang Guangyi's team wants to take advantage of the excellent properties of gallium nitride, they must first solve the problems of cost and reliability.

It must be ensured that the device is not affected in any way in a high temperature environment.

Xu Yuan quickly figured out the situation on the way and understood the problems that Zhang Guangyi's team was currently facing.

However, he didn't know what to say about this. He thought that Zhang Guangyi had really given him a difficult problem this time, and it was still unknown whether he could help.

But the interesting thing is that neither of them is telling the story now.

Soon, led by several researchers including Zhang Guangyi, Xu Yuan also came to their project laboratory.

At this point, Zhang Guangyi could no longer bear it and expressed his thoughts to Xu Yuan.

Mainly in his opinion, Xu Yuan has a very high level of research in both materials and radar systems, and is the person with the greatest hope of helping to optimize gallium nitride technology.

……

(End of this chapter)