Insightful article from Satcube, a pioneer in satellite communication technology. In a world increasingly dependent on seamless global connectivity, Satcube’s expertise in cutting-edge antenna systems is driving innovation and transforming the way we communicate:
Isn’t it amazing that we can use space to transmit data and communicate with each other down here on earth, all this thanks to little waves. The most critical component to make this work is the antenna system and that’s where it can get a bit complicated. Good news is, as a satellite communication terminal manufacturer, this is our thing! So, welcome to the antenna jungle, we’ve got all the information you need.
Since the existence of radio and other waves were discovered, antennas invented and made popular thanks to scientists like Heinrich Hertz and Guglielmo Marconi in the late 1800’s, space-born communication and antenna development have gone a long way. There are nowadays numerous types of antennas available, and applications are many as well (satellite communications, but also GPS, broadcast, weather, radar, etc.).
As far as satcom terminals and antennas are concerned, the most important factors to consider are frequency range (which band to use), efficiency (how good the antenna is at converting power into radio waves), directivity (how focused the energy transmitted by the antenna is to guarantee the signal can travel long distances between earth and a satellite), and polarization properties (the orientation of the radio wave). But let’s start from the beginning.
The role of the antenna in satellite communication
To communicate through satellite broadband goes as follows: a data packet (voice, text, http, or else) is transmitted from a remote terminal to a satellite and is then sent down from the satellite to a hub. To do so, the terminal needs an antenna system with a Block up converter (BUC) which will convert the frequency of the modem (often L-band) to RF (C, X, Ka or Ku) and amplifies the signal. The antenna focuses the energy from the BUC (so called antenna gain) to ensure that the signal reaches the satellite. The satellite then receives, amplifies and converts the frequency of the signal before sending it back to the hub, which is then connected to our earthly internet. In the downlink direction, from hub to satellite to terminal, to receive data, the packets will follow the opposite way: be sent from the hub to the satellite which will convert the frequency back to the terminal, where the antenna and the Low-noise block down converter (LNB) will amplify the signal and convert again to the modem’s band.
That is why the antenna has a central role – as it determines the strength of the signal in both directions and will therefore directly affect the quality and speed of your internet connection. Stronger and more directed radio frequencies mean less losses as well as less signal disturbances.
Main types of antenna systems for satcom terminals
While there are many different types of antennas (horn, helical, etc.) suited for different applications, as far as satellite communication is concerned, it is mainly 3 kinds you will encounter:
The most classical antennas are parabolic dishes. They are high-gain antennas, meaning they are effective at directing a tight beam of radio waves to satellites, even at long distances like for GEO constellations. However, due to the shape, those terminals are often a bit bulkier and heavier than other manpack terminals, and setup time will be longer than with other antenna types.
Flat-panel antennas (FPAs) is what we work with at Satcube with our Satcube Ku and Satcube Secure terminals. FPAs represent a leap forward in satellite communication technology as they make it possible to develop small-size and lightweight satcom terminals. Flat-panels are high-gain, directional antennas and have emerged as an ideal satcom solution thanks to their versatility and performance capabilities. Satcube has always had its users at the core of what we do, which is why SWaP-C – i.e. optimizing size, weight, power consumption and cost – has been a focus since the start. In that sense, flat-panel antennas are an ideal choice as they provide superior link performance in a smaller form-factor, thus making satellite broadband more accessible to all, both from a cost perspective, but also from a usability standpoint. Those type of antennas are very low-profile and quick to setup (even more so when coupled with our intuitive user interface!) making them ideal for a wide range of users.
The last type of antennas frequent in satcom applications are phased array antennas. They are a more advanced and use electronic beam steering, which enables them to set the direction of the signal without moving the antenna itself. This is especially frequent for LEO constellation as the position of the satellite in the sky changes and the terminal can follow it and direct the signal towards it without the need to physically move it. One of the main benefits is that phased array antennas can track the satellite in real-time and have shorter interruption times during satellite handovers thanks to instantaneous change of beam direction. However, this more advanced technology comes with two main downsides. Firstly, performance at low elevation will be severely degraded compared to a flat-panel or parabolic antenna (e.g. you would lose about 60% of the performance at a 30° elevation), which can only be compensated by bigger size (thus worsened SWaP-C). The second is that those types of antennas require more energy to emit a signal of similar strength due to the nature of the semiconductor technology used in the antenna, which in its turn leads to shorter battery time, increased thermal footprint, and overall shorter lifetime.
The future of satcom antennas
At Satcube, innovation is one of our key values and a lot of our time and resources go to antenna research and development. We’re currently working on several PhD projects with major European universities and supported by the European Space Agency on advanced flat-panel and phased array antennas, as well as LEO applications. The emphasis is developing new antenna technologies that further push the boundaries of energy efficiency, i.e. improving the maximum percent of electrical power converted to radio waves instead of heat. In the case of phased arrays, we’re researching how to improve antenna performance at low elevation angles. We are very excited for all the future of satellite communications holds and to help bring it forward!
