How Modern LEO Satellite Technologies are Changing the Space Race

Introduction

In the rapidly evolving landscape of satellite technology, Low Earth Orbit (LEO) satellites have emerged as a game-changing innovation. These satellites, positioned at altitudes ranging from approximately 100 to 500 miles above the Earth’s surface, have revolutionized the way we communicate, gather data, and monitor our planet. LEO satellites play a pivotal role in various sectors, including telecommunications, Earth observation, scientific research and national security. It is estimated that the commercial satellite constellations will grow from 35% to 70% by 2029. Approximately 65% of this growth will be in applications found in communications, involving satellite networks that span low Earth orbit (LEO), medium Earth orbit (MEO), and geosynchronous Earth orbit (GEO) satellites.

Comparative Overview of Satellite Orbits

GEO satellites rotate in the same direction and speed as the Earth. Therefore, it is at a fixed position to the Earth to ensure a fixed pointing angle from anywhere on the Earth. On a mobile platform, the Earth-based GEO directional antennas must be continual and directly align toward the assigned GEO satellite. These traditional Earth-based satellite antennas are large, expensive and have many moving parts – requiring routine maintenance.

MEO satellites, like GPS, are commonly used for navigation. MEO satellites have their advantages, but similar to GEO satellites, they do have high launch and maintenance costs. Both GEO and MEO satellites serve a purpose, but they come at the cost of latency and data speeds.

Figure 1: LEO, GEO, MEO satellite coverage areas.

LEO satellites offer distinct advantages over their geostationary and medium Earth orbit counterparts. They provide low-latency (30 times more responsive than GEO) and high-speed internet connectivity to remote and underserved regions of Earth. LEO satellites require hundreds to thousands of units to cover the Earth’s surface, enabling a cross-linked mesh network. This mesh networking not only improves global coverage but also improves connection reliability – for example, if one satellite goes offline, another one can step in to support any signal loss. Currently, most LEO satellite deployments are driven by private companies and government agencies. Companies like SpaceX, OneWeb, Amazon's Project Kuiper and Telesat have invested heavily in LEO satellite deployment. This has ushered in a new era of global connectivity and data accessibility.

Satellites play a big role in connecting the world. As shown in Figure 3, they do two main things: talk directly to Earth supporting multiple end user terminals across various industries and backhaul that data to Earth either directly or through inter-satellite links (ISLs). With more LEO satellites being launched, communication is getting even faster and covers more area, making it easier to send information from space to Earth with less delay.

Figure 2: Non-terrestrial networks including terrestrial inter-satellite link (ISL) and application connections.

Basic Satellite Components

The satellite is a complex system that contains many functionalities depending on its mission. This article focuses on the transponder components inside the communication payload module. The transponder is a subsystem in the payload module that sends and receives signals. It typically contains amplifiers, receivers, and transmitters to serve communication purposes.

Figure 3: Example of basic satellite components.

Frequency Spectrums for Satellite Communications

Most satellite deployments are L to Ka-band. However, there are more modern satellites moving toward higher frequency bands like Q/V and E spectrums, as shown in Table 1 below.

Table 1: Allocated frequency spectrum for SATCOM communications.

To serve 5G non-terrestrial network application, 3GPP also allocated NTN bands. Table 2 shows both the current NTN bands in L&S band as well as the newly proposed bands in the K and Ka band.

Table 2: Satcom Frequency bands.

The Integration of Satellites in the 5G Network

There's a growing adoption globally of broadband internet services offered by large LEO satellite constellations. This interest, along with the integration of satellite networks into the 5G ecosystem, is further propelling satellite market growth.

Moreover, cellular communications are becoming part of the satellite ecosystem. The introduction of 3GPP 5G wireless technology in Release 17 has made it possible to adapt 5G systems for non-terrestrial networks (NTNs). NTNs aim to expand network coverage worldwide, especially in rural and remote areas, and facilitate direct connections between mobile devices, the Internet of Things (IoT), and commercial autonomous vehicles to satellites. This integration enables the satellite industry to leverage the 5G ecosystem's economy of scale.

The 3GPP Release 17 specified both 5G new radio (NR) NTN and 4G IoT NTN, as described in Figure 4. It focuses on utilizing satellite transparent payload architecture and UE with GNSS capabilities. Figure 4 shows the expected use cases for 5G NTN.

Figure 4: NTN 5G NR and IoT use cases that complement each other.

Additional uses would be for…

• Under-covered areas like agriculture, mining and forestry.
• Disaster communications when land communication networks are damaged.
• Broadcasting information over a very wide area.

A Final Word

This article explored the impact of LEO satellites on global communication, highlighting their key role in sectors such as telecommunications and Earth observation. LEO satellites are set to double in commercial constellations by 2029, offering advantages like low-latency high-speed internet in remote areas through a mesh network. Investments from major companies like SpaceX, OneWeb, and Amazon's Project Kuiper marks a significant shift towards enhanced global connectivity. Additionally, we reviewed the integration of satellite networks with the 5G ecosystem through NTNs, expanding frequency spectrums to improve coverage, especially in underserved regions. This integration not only propels market growth but also highlights the satellite industry's crucial role in advancing the 5G infrastructure and global communication capabilities in a concise overview.

In Part 2 of this series, we further discuss NTNs and how communications for these services will be achieved. We will also explore the trends in LEO satellite deployments and how they are driving new advancements in RF front-end design.

For more on this topic and solutions we encourage you to view these collateral pieces – our webinar Key Components for LEO Satellite Systems, our sponsored eBook RF Technology Trends for LEO Satellite Systems, and our blog on Ka-Band Satcom Trends and Power Amplification Challenges. Additionally, you can find more interesting collateral on this subject by visiting our Qorvo Design Hub for a rich assortment of videos, technical articles, white papers, tools and more.

For more information on this and other Qorvo 5G and 6G base station design solutions please visit Qorvo.com or reach out to Technical Support.