China’s first! How are high-throughput satellites with over 100G capacity made?

Recently, China’s first Ka-band high-throughput satellite with a capacity of over 100G, the ChinaSat 26 satellite, was successfully positioned. This satellite will fully open a new era of satellite Internet services in my country. The ChinaSat 26 satellite was developed by the Fifth Academy of Aerospace Science and Technology Corporation (hereinafter referred to as the Fifth Academy) and was successfully launched on February 23 this year. The satellite is an important part of the high-throughput satellite network resources in the national space infrastructure.

On February 23, the Long March 3B carrier rocket successfully launched the ChinaSat 26 satellite (photo by Cha Yuanyuan)

Wei Qiang, commander-in-chief of the ChinaSat 26 satellite of the Fifth Academy, introduced that the satellite is equipped with 94 user beams and 11 gateway beams, covering the entire territory of China and surrounding areas, and will be used for fixed terminals, vehicle-mounted terminals, ship-mounted terminals, and airborne terminals. Provide high-speed broadband access services.

After the satellite is put into operation in orbit, it will form a Ka-band high-throughput satellite application system network with ChinaSat 16 and ChinaSat 19, which can provide effective communication technology means to meet the Internet needs of domestic Chinese-funded enterprises to "go global". It is widely used in Internet services such as airborne, shipborne, and land mobile tools, as well as emergency, private network, universal telecommunications services, ubiquitous IoT and other services. It can also provide strong support for the country to establish the "Belt and Road" space information corridor.

What is the strength of ChinaSat 26 satellite?

In April 2017, my country successfully launched its first fully independently developed Ka-band high-throughput satellite, ChinaSat 16, which broke the monopoly of foreign countries’ global advanced satellite communication technology and enabled my country’s high-throughput satellite Internet to achieve zero breakthrough.

The debut of the ChinaSat 26 satellite means that the development of my country's high-throughput satellites has taken a solid step forward and reached a new level.

Wang Fengchun, chief designer of the ChinaSat 26 satellite from the Fifth Academy, said that the ChinaSat 16 satellite was developed using the Dongfanghong 3B platform, while the ChinaSat 26 satellite was developed using the Dongfanghong 4 enhanced platform, which has a stronger carrying capacity.

Compared with the ChinaSat 16 satellite, the ChinaSat 26 satellite has stronger capabilities, a wider range of uses, supports more users, and has higher speeds. It can be said that it has achieved an "upgrade" and will bring a better experience to users. .

Satellite transfer (photo by Gao Jian)

At the same time, ChinaSat 26 is also the high-throughput satellite with the highest localization rate.

Compared with other civilian and commercial satellites developed based on the enhanced version of Dongfanghong 4, the localization rate of the payload products of the ChinaSat 26 satellite has more than doubled, putting it in a leading position.

During the development process, the research and development team independently innovated and pooled their wisdom to tackle key problems, achieving the localization of six products, including the fourth-generation Ka-band low-noise amplifier, Ka-band inverter, low-noise amplifier power supply, and three types of Ka-band sequential microwave switches.

The performance of these six products has reached the international advanced level and has been included in the payload product spectrum of the Fifth Academy, achieving independent controllability and comprehensively improving the level of localization of payloads.

"Ka-band payload is a major difficulty in development. Taking the Ka-band sequential waveguide switch as an example, every step of design, simulation, and process realization is not easy. The product finally passed the appraisal and its performance reached the world's leading level. That moment was unforgettable . This kind of excitement and emotion runs through every moment when every problem is solved during the development process." Wang Fengchun said.

How are high-throughput satellites with over 100G capacity made?

To achieve high-throughput goals, satellite-ground integrated design is crucial. Only through joint design of satellite and ground application systems can the performance of the entire satellite-ground system be optimized.

Wang Fengchun introduced that since the launch of the project, the development team has jointly carried out design with users, optimizing system indicators such as satellite user beam width, bandwidth allocation and gateway station location based on the business needs of different regions, as well as the design and operation services of satellite-ground systems. The overall performance is greatly improved.

ChinaSat 26 is the first domestic satellite to fully use the 27-30GHz frequency band, which is 500MHz wider than previous communication satellites. Frequency broadening can make satellite communication capabilities stronger, but it also places higher requirements on the performance of the receiving system.

In this regard, on the one hand, the team optimized and iterated the load frequency plan, conducted reasonable bandwidth allocation and frequency reuse, ensuring that the load obtained the best carrier-to-interference ratio and optimal system performance; on the other hand, the team made a breakthrough in the ultra-wideband low-PIM integrated feed design , ultra-wideband low-noise reception and other new technologies, greatly improving load performance.

Looking at the schematic diagram of the load bay, we can see that in a limited space, countless waveguides and cables are densely and neatly installed and arranged, almost occupying the entire space. This picture intuitively shows the layout of the ChinaSat 26 satellite. Delicate and technically complex.

The ChinaSat 26 satellite has a large number of payloads, radio frequency wires and waveguides. Compared with most other civil and commercial satellites based on the Dongfanghong 4 enhanced platform, it is more than doubled, setting a new domestic high.

Xu Chunsheng, the overall chief designer of the Zhongxing 26 satellite of the Fifth Academy, said that the design of the satellite payload bay went through many rounds of iterations and lasted about a year. The team established a digital model for each product, and used methods such as three-dimensional remote linkage design of load links and layout to solve the layout design problems of high-density, multi-beam complex links, and built a system for the difficult layout design of high-throughput satellites. Technical baseline.

Satellite hoisting (photo by Gao Jian)

The development of the ChinaSat 26 satellite began at the end of 2019 and was launched in early 2023. The development cycle highly overlapped with the COVID-19 epidemic. In the end, the team successfully completed the task. None of the satellite indicators were out of tolerance, and all were better than or met user requirements.

“After three years of hard work with designers, I can proudly say that the ChinaSat 26 satellite development team is a very good team, adhering to the rigorous and meticulous work style of aerospace, with excellent technical skills and selfless dedication. We have overcome the great impact of the COVID-19 epidemic on research and development and achieved a double victory in satellite development and epidemic prevention!" Wang Fengchun said.

The first high-throughput satellite application network will be integrated into all walks of life

After its launch, the ChinaSat 26 satellite will also be networked with the existing two high-throughput satellites, ChinaSat 16 and ChinaSat 19, to provide users with high-speed network communication services and satellite Internet access services, serving the country Build basic network capabilities for the development of the digital economy.

After this application network is formed, the three high-throughput satellite broadband Internet services are connected, and each has its own focus. This network can provide professional scenario-based services in emergency, aviation, navigation, energy, forestry, transportation, geology, environment, telecommunications universal services and other industries.

Closing the hood (photo by Gao Jian)

In the fields of aviation and navigation, after aircraft and ships are installed and deployed with airborne and shipboard terminals, they can rely on high-throughput satellite networks to connect with ground communication networks in real time to provide safe and reliable communication and Internet access services for staff and passengers.

For core businesses such as forestry and grassland industry resources and ecological monitoring, fire early warning, and emergency response, this high-throughput satellite application network can take the large-capacity satellite communication network as the core and integrate navigation and remote sensing satellite technologies to form normalized resource and ecological monitoring capabilities. , providing support for refined management and collaborative application in forestry and grassland and other industries.

In response to the problem of weak terrestrial broadband network coverage in remote areas, high-throughput satellite networks, with their advantages of wide coverage and easy access, can provide a wide range of distance education and telemedicine services for people's lives, and can be used in grasslands, deserts, mountains, Areas such as oceans and other areas that are inaccessible to terrestrial communication networks provide people with stable and reliable satellite broadband high-speed Internet access services anytime, anywhere.