Yang Jie's goal is to reduce the cost as much as possible, rather than developing a very advanced low-orbit communication satellite, and to make use of mature domestic satellite technology as much as possible, even if the satellite platform technology is relatively backward, but as long as it can be equipped with a high-power signal transmitter developed by Huaxing Group Company.

Motorola launched the Iridium plan in that year in each satellite mass of about 670 kilograms, the power of 1200 watts, the use of three-axis stable structure, each satellite of the channel of 3480, from the technical point of view, the Iridium mobile communication system has broken through the inter-satellite link and other key technical problems, the system infrastructure and procedures have been initially completed, all aspects of the system research and development have made important progress, during this period there are dozens of companies around the world have participated in the implementation of the Iridium plan, it should be said that the establishment of the Iridium plan in the early stage, The operations and implementation have been very successful.

However, the Iridium system has a data transfer rate of only 2.4 per second, and can only send short e-mails or slow faxes except for phone calls, which is simply not enough to meet the current needs of the Internet.

And the Iridium phone is too clumsy, inconvenient to use, and requires special training.

Motorola's Iridium dual-mode phones weigh about 454 grams, and Kyocera's Iridium single-mode and dual-mode phones weigh 400 grams each, and they're much more bulky than digital cellular phones that weigh less than 100 grams, and each phone must come with a whole backpack of accessories, and the actual efficacy of each accessory is often puzzling.

Another is that it is expensive, the Iridium system is connected to the cellular telephone network, and must adapt to different regional transmission standards, and the resulting conversion cost brings great inconvenience to users. When traveling around the world, in order to connect to the local cellular phone network, the dual-mode mobile phone has to be replaced with a calling card that suits the local regional transmission standard, and the price of each card is about $660-900, which is equivalent to buying a new mobile phone.

And this system also has the biggest drawback, that is, it cannot absorb the signal in the building, and those who can afford to buy an Iridium phone must set up a day line or run out if they want to use it indoors or in the car, who will be able to absorb it?

Moreover, the Iridium system is under the pressure of the schedule, and the first problem is that supply exceeds demand. There are only two companies that produce Iridium phones, one is Motorola in the United States and the other is Kyocera in Japan, and the latter has a high call failure rate due to technical problems, so it was not put into commercial production in time.

Motorola's factories produce 1,000 Iridium phones every day, and when they are shipped, they are usually shipped to 12 Iridium gateways scattered around the world, and then handed over to partners and business suppliers in various countries.

At the beginning of the Iridium system service, the call drop rate reached 15%, the important reason is that the software is not good, and the call drop rate is often dropped when transferring from one satellite to another, and then the call drop rate is reduced to 8%, but it is still too high compared to the drop rate of only 0.33% in the terrestrial communication network.

Yang Jie's mind is not to compete with the ground communication network, but to apply it to automobiles, fishing boats and various military weapons and equipment, these customers are not sensitive to price, if they directly enter the mobile phone terminal, it is asking for trouble.

And until the problem of the skills of these systems itself is solved, Yang Jie will not be in a hurry to build this network on a large scale.

However, Yang Jie still believes that his low-orbit communication network will be more than one degree higher than the Iridium system in terms of data transmission speed.

Even if there are only a dozen signal transponders on a satellite, the total capacity of a satellite has reached 90, and a satellite can meet at least 9,000 terminals on the ground at the same time to achieve a transmission rate of 10 megabytes.

Of course, this is only theoretical data, and the satellite will attenuate in the process of signal transmission, but this data is already very remarkable.

Huang Lao heard that Yang Jie was not going to launch the satellite immediately, but to do skill development and experimental testing first, so he nodded and said: "I didn't expect that your Huaxing Group Company has come to such a point in communication skills, and it can be said that the most difficult bone to gnaw off on the basis has greatly reduced the risk." ”

She had also participated in the development of the satellite autonomous control system before, and she also knew a lot of technical experts, and when she heard Yang Jie develop low-orbit communication satellites, she immediately got up and took out a communication book from the study, and gave Yang Jie the communication methods of several experts in this field.

For Yang Jie wants to enter the field of aerospace satellites, Huang always recognizes it very much, she knows that her disciple is a skill maniac, and he is also a very shrewd businessman, and he is very precise in skills and trade, and he has a great influence in the high-level and military, and his energy is very large.

After chatting with Yang Jie and Bai Bing for a while, Huang Lao learned that the two of them were going to get married at the end of the year, and she said excitedly: "You two are finally about to achieve positive results! ”

Yang Jie smiled and said, "That's a must!"

A few days later, Yang Jie appeared in an office in the Military Commission building and used a projector to show Zhang Hai and other military bigwigs his plans for low-orbit communication satellites, and these bigwigs listened very carefully.

"Ladies and gentlemen, our company intends to trial produce the first generation of low-orbit communication satellites in two to three years, and conduct various air and ground experimental tests through at least four satellites, if there is no big problem, we will set up a network of at least 24 satellites in the fifth year, comprehensively covering the Asia-Pacific region, and begin to provide large-capacity data transmission services for the military and China。 ”

Yang Jie opened a transparent box at this time, which contained two band RF power amplifiers.

"This is the two band RF power amplifiers produced by our group company, the one on the left is the gallium arsenide RF power amplifier we produced two years ago, and the one on the right is the gallium nitride RF amplifier that our company trial-produced a month ago. ”

Zhang Haiping also took the transparent box, and he saw that the gallium arsenide RF amplifier on the left was about the size of the top area of a pencil eraser, and the gallium nitride amplifier was about the size of a grain of raw rice.

He picked up a magnifying glass and examined the two amplifiers carefully, creating a GaAs amplifier requires more components and more complex circuitry, while a GaN amplifier requires fewer active components and a much more sketchy circuit.

"Ladies and gentlemen, the gallium nitride RF amplifier we have trial-produced is much smaller than the gallium arsenide amplifier at the same power, and the power consumption is lower, and the heat generated is also lower, we can make the size of the satellite very small, and the ground terminal absorber can also be made small, and it will not take up the space of the blueprint equipment. ”

Yang Jie said with a smile: "Generally speaking, these two devices are not large, but when they are specifically used in phased array radar, for example, the advantage of gallium nitride is obvious." Active phased array radar may have 70,000 components, each of which is servo-based on a monolithic microwave integrated circuit transmitting and absorbing module, the size of the GaN monolithic microwave integrated circuit can be smaller, combined with the high power output and higher operating frequency of GaN, GaN devices are certain to replace GaAs in phased array radar. Moreover, gallium nitride is also suitable for high-power RF switches and other control components, and is used in a wide range of fields. ”

"Your company has really made something amazing!"

Zhang Haiping looked at Yang Jie with some excitement: "Now these gallium nitride devices can be produced on a large scale?"

"Report chief, our company's yield is still relatively low, but we are working on technical research, it is estimated that the yield can reach a more satisfactory state within a few years, and we are also developing larger GaN wafers to reduce the cost of GaN devices. ”

"Okay, good!" Zhang Hai and the other military bigwigs all nodded excitedly.

Reborn University Tyrant Latest Chapter 5575 Crossing the River by Feeling the Stones!Website: