Chapter 167 Frequency Debate
In the field of radar, frequencies, or electromagnetic wave wavelengths, are divided according to certain rules.
When radar was first used, it was only used for long-range search. The antenna of this radar was very large, similar to a TV antenna. The wavelength was in the meter band, which was called P-band.
(Previous band, P is the first letter of Previous).
Later, with the continuous improvement of technology, the 23 cm band was selected as the electromagnetic wave for search radar. This band was defined as L band (long wave band, L, the initials of Long). Later, there were some changes. The central wavelength of this band became is 22 cm.
After that, radar with a wavelength of 10 centimeters appeared. Compared with the previous L-band, this band was defined as S-band (short-wave band, the first letter of Short, which is an electromagnetic wave with a shorter wavelength than the L-band).
These bands are all used for search. The shorter the wavelength, the higher the accuracy of the radar. Therefore, in the later period, after wanting to use radar to accurately find the distance and position of the target, fire control with a wavelength of 3 cm electromagnetic waves appeared. For radar, this band is called the X-band, and X represents a certain point on the coordinates.
X-band radar has high accuracy, but it also has a disadvantage, that is, the shorter the wavelength, the closer the radar's irradiation distance. Therefore, in order to combine the advantages of X-band and S-band, a radar with a wavelength of 5 cm has appeared. This band is called C-band (combined band, C is the first letter of Combined).
At that time, in addition to the United Kingdom, the Germans also began to independently develop their own radar. Rigorous German engineers chose the 1.5 cm band, which was called the K-band (K, the initials of Kurtz, meaning "short" in German).
Unfortunately, the Germans have a problem with this wave band. This electromagnetic wave happens to be strongly absorbed by water vapor. As a result, radar in this band cannot be used in rain and foggy weather. In order to avoid this absorption peak, two improved bands have emerged, one is slightly higher than the K-band frequency (Ka, English K-above, above the K band) and slightly shorter (Ku, the English K-under , below the K-band) band.
Because the naming method of these bands was too confusing, the international community later came up with a reclassification method. They compared the naming according to the order of electromagnetic waves and the order of English letters. However, this most recent method is still used in China. Commonly used band naming methods.
Page 14 chose the S-band, which is a wavelength of ten centimeters, while Aerospace System 23 chose the C-band, which is a five-centimeter wavelength. The latter has higher accuracy and can be used to directly illuminate targets and be used as a fire control radar, killing two birds with one stone.
However, the biggest problem with the latter band is that because its wavelength is shorter, its search distance will be much shorter with the same radiation power.
Same as the plan of Institute 14, that is, on a rectangular area of four meters by four meters, if the C-band is used, the search distance will not even reach 200 kilometers, which is only 1560 kilometers!
After the collapse of the Red Empire, it is said that Lao Maozi conducted a series of cooperation with China. The phased array radar that Lao Maozi transferred was called Sea Lion. It is a C-band active phased array radar with an actual effective range of 150 kilometers. .
Of course, based on Lao Maozi's level of electronics industry, this kind of active phased array radar may not be possible to build. It is probably just a PPT product.
Although the number of active phased array radars required by the Navy is not particularly large, it is still a huge order. Moreover, the experience gained in the Navy's project can also be used in the Air Force's fighter aircraft and ground air defense forces. superior.
So, this is a big cake.
At this point, fierce debate began as both sides proposed their own plans.
"The American Aegis system uses the S-band. Therefore, their phased array system can only be used to find targets. It also requires special guidance radar to illuminate the target. The actual fire channel is limited by the target illumination radar. Quantity does not fully provide the ability to resist saturation strikes."
"That's right, the MK-99 fire control subsystem of the Aegis weapon system is controlled by four AN/UYK-20 computers, each of which controls an AN/SPG-62 target illumination radar. It can deal with up to four targets at the same time. Even if The phased array radar can be pre-guided. At most, it can intercept 12 targets in one wave of attacks, and it cannot achieve the ability to resist saturation attacks at all."
“If the C-band is used, the radar irradiation distance is only more than 100 kilometers, which is simply unable to meet the needs of the Navy. The hard target proposed by the Navy is that the search distance is at least 200 kilometers.”
"This distance can be changed. We have more than just phased array radar on our warships. It consumes too much power. We must have a special sea search radar. As long as we install our meter-wave sea search radar, it can be achieved. The search distance is three to four hundred kilometers, won’t this problem be solved?”
Countless people have commented, some support the 14th institute, and some support a certain aerospace institute.
For the Navy, it is quite critical. After all, they do not have the ability to support two projects at the same time. If the route is chosen wrongly, it will mean huge waste.
Wu Shengli looked at Mr. Wu: "Now, please ask our experts in the development of relevant missiles to analyze it for us. Mr. Wu, please tell us."
Lao Wu was named.
The development of missiles is the responsibility of the Second Aerospace Institute. Mr. Wu also belongs to the aerospace system. Therefore, from a normal perspective, Mr. Wu should support the 23rd Institute of the Second Aerospace Institute.
Mr. Wu's eyes looked at the people present, and finally settled on the corner.
"Dear leaders, we encountered big problems during the development of our project. Later, with the help of Mr. Qin of Mingzhou Shipbuilding Industry Group, we made breakthrough progress. Although Mr. Qin is not a professional in our weapons system Yes, but he has a lot of experience and a long-term vision. Now, I want to hear his opinion first."
What? My opinion?
Qin Tao was a little surprised. These old guys are all old foxes. He didn't want to offend others, so he pushed himself out?
However, although Qin Tao had some resentment in his heart, since he was asked to speak, he was not too polite. After all, since he participated in such a meeting, he really wanted to use his abilities.
"First of all, I know that the two hundred kilometers proposed by the Navy is a hard target. Even the two hundred kilometers target is far from enough. It needs to reach three hundred kilometers or even four hundred kilometers." Qin Tao said: "This It’s not about launching satellites, but the real needs of the navy. Our current goal is just to intercept enemy aircraft and anti-ship missiles launched by the enemy, but in the future, there will be more and more types of targets to intercept, not only aircraft There will be aviation-type ones, and there will also be ballistic-type ones.”
“Ballistic? You mean ballistic missiles? How could those things be intercepted?” Immediately, those who supported Institute 23 began to object.
One of the great features of ballistic missiles is that they cannot be intercepted, because they fall too fast, their trajectory is high, and their interception window is very narrow, making it impossible to intercept them.
"Everyone, we don't want to be a frog in the well." Qin Tao looked at the opponents: "Even if we don't mention that the rubber-covered anti-missile system deployed by Lao Maozi in the 1960s has successfully achieved the purpose of intercepting ballistic missiles, just say that now, the United States The Patriot missile system already has the ability to intercept short-range ballistic missiles, that is, Lao Maozi's Scud missiles. The Lao Maozi Army's S-300V system has already set interception of ballistic missiles as a goal during the development stage. The Navy If the main air defense ship only has a search distance of more than 100 kilometers, wouldn't it be blind?"
“But, we can add additional long-range search radar!”
Qin Tao rolled his eyes at the other party.
“But, if S-band is used, how will the missile be guided?”
"Well, I don't know the status of our missile development." Qin Tao said: "So, I still use international technology. At present, the TVM guidance method is a trend. This guidance method can integrate semi-active The advantages of guidance and command guidance. If you use this method, you must use target illumination radar. However, this guidance method has begun to become outdated. Advanced air defense missiles and air-to-air missiles have begun to use active guidance methods."
Semi-active guidance requires the rear to provide target illumination capabilities. Active guidance is not needed. It only needs to fly within tens of kilometers near the target, and then it can use its own radar to lock the target.
This type of missile has the ability to launch and forget. Although it theoretically requires mid-course irradiation, the final attack is completely autonomous.
“If our missiles are going to use this guidance method, or will use this method in the future, then target illumination radar is not necessary.”
Qin Tao glanced at those who were unconvinced and continued: "Of course, some people will say that it is impossible for me to launch satellites with our technology. Therefore, I have another way to solve the problem. In our S-band On the main phased array radar, a small-area C-band phased array radar T/R component can be added, so that the radar of the 14th Institute can have both long-range search and target illumination capabilities."
Countless people’s eyes lit up.
Yeah, why didn’t they think of it?
The large-area C-band is not suitable because the search distance of this thing is too close to meet the needs of the navy. However, the S-band radar is not very accurate and cannot complete terminal guidance. Now, in the large-area S-band front On top, wouldn’t adding a small-area C-band array perfectly solve the problem?
“Huh, you said it nicely. How can we solve the problem of electromagnetic compatibility by combining two different radar arrays?” Some people began to refute Qin Tao’s layman’s theory.
"We will solve the problem of electromagnetic compatibility!" Mr. Ben said: "Although Mr. Qin is an outsider, the solution he proposed perfectly solved the problem of our inability to be irradiated in the S-band. I think it is The best solution. We have listed eighteen technologies that need breakthroughs, and this electromagnetic compatibility is the nineteenth one!"
There are a large number of electronic devices on a warship, and interference from these electronic devices is a big problem.
“Yes, the problem of electromagnetic compatibility should be solved.” At this moment, another voice spoke.
Pan Lao, who designed two destroyers before and after, the 051 and 052 destroyers, expressed his support.
"I think the plan proposed by Mr. Qin can perfectly solve our problem." Mr. Wu finally spoke.
Mr. Wu, who also came from the Second Academy of Aerospace and was responsible for developing missiles, actually expressed his support for the project of the 14th Institute at this time!
23 The faces of everyone in the house suddenly changed.
"It's getting late. Let's hold the morning meeting here first. Let's go to the cafeteria to eat! We will discuss relevant decisions in the afternoon." Wu Shengli spoke.
The decision cannot be made at this time. At noon, the various leaders of the navy will definitely hold a small meeting to exchange opinions with each other before making a final decision.
So, everyone left the conference room one after another.
Qin Tao was alone, walking forward with the crowd. After all, this was his first time attending such a meeting, and the people walking around him were all big guys, so he couldn't talk to him.
However, after taking only a few steps, there were rapid footsteps behind him.
Lao Ben rushed over.
“Mr. Qin, Mr. Qin!”
Qin Tao turned around and looked at Mr. Ben in surprise: "Old Ben, you?"
“Mr. Qin, your proposal is really from a high position. Let’s talk while walking.”
“Well, I really don’t know much about professional knowledge. What I just said are all the words of a layman.”
"No, these words are very important." Mr. Ben said: "Only outsiders can put aside the limitations of various technical details and put forward pioneering opinions."
Qin Tao also felt flattered by being held up so high by Mr. Ben.
"There are still many problems we encounter. For example, the cooling of radar antennas is a big trouble. The mainstream international solution is water cooling, but this will greatly increase the complexity of the system." Mr. Ben has already proposed a more detailed solution technical issues come.
A radar antenna is a device that converts electrical energy into electromagnetic energy. This conversion efficiency is quite low. Even for active phased array radar, it is about 25%. The remaining energy is turned into heat. .
If the excess heat is not dissipated, the system will overheat.
“Water cooling is too complicated. To reduce the structural difficulty, we can use air cooling. Put the radar antenna in a cover to ventilate it and force the heat to dissipate. You can also use air conditioners to blow cold air directly into it.”
Ben Lao’s eyes lit up.
"Of course, it has to be solved in terms of materials. When we first developed it, in order to solve the problem of availability, we could first use silicon bipolar transistors or gallium arsenide semiconductor materials. These components need to be in an environment below 60 degrees Celsius. The temperature can only work normally. When our technology comes up, we can use gallium nitride to greatly increase the operating temperature and increase the detection distance."
“Mr. Qin, how can you be an amateur? What you said is too professional!” Mr. Ben sighed with emotion.
(End of this chapter)