Company: Analog Devices
Category: Aerospace/Military/Defence Product of the Year
The space industry is undergoing a metamorphic change that hasn’t been seen since the cellular infrastructure revolution. There are over 3 billion people on the planet that do not have access to the internet. Trying to provide connections through traditional techniques such as fiber or microwave backhaul requires millions of dollars of investment. The only way to provide high speed internet to the underserved geographies is through a satellite connection. The question is, how?
The traditional Geosynchronous Earth Orbit (GEO) satellite utilizes a â€œbent pipeâ€ architecture which broadcasts its signal over a large geographic area. This technique is very popular for television and radio but is not well suited for delivering high speed internet. Several techniques have been used to help maximize the data rate from GEO satellites, one of them is beamforming antennas. Beamforming antennas are often multi-beam beam antennas where several beams can be transmitted to different geographic areas simultaneously. But even using these techniques, the latency from a satellite in GEO orbit to earth is still not adequate, hence the deployment of Low Earth Orbit (LEO) satellite constellations.
These LEO constellations can be on the order from several hundred to thousands of small, lower cost satellites as opposed to a single, expensive GEO satellite often with less stringent mission requirements. Because of the size of the LEO satellite and the sheer number of satellites; size, weight, power, and cost are critical (SWaP-C). Since these satellites are in lower orbit, the latency is much less but now a new problem needs to be solved, the LEO satellite is not stationary and is orbiting the earth at 17,000mph â€“ how does the satellite maintain connection to the user terminal or gateway? Beamforming is the method of choice, but the traditional method of beamforming utilizes discrete phase shifters and attenuators and is often constructed in a large expensive hermetic module. The only way to bridge this gap is to have a small, low-power beamformer integrated circuit (BFIC) that can be used in space at a reasonable cost.
Analog Devices has developed such a part, the ADAR3000 and ADR3001 BFICs – for more informtion go to https://www.analog.com/en/products/adar3000.html#product-overview. These highly integrated, low power BFICs are the first commercially available 4 beam/16 channel that support the K/Ka band satcom bands. Each channel contains a programmable step attenuator and programmable time delay for beam steering and draws less than 12 mW/channel. Not only is there a high degree of RF integration in these BFICs, but there is also a sophisticated digital definition that has memory to support quick and efficient beam state selection via program control over the SPI bus. Each device can support beam hopping and raster scanning which are critical for LEO satellites to be able optimize spatial and frequency reuse.
The unique 4 beam/16 channel architecture can easily scale depending on the number of beams required as well as number of elements. By adjusting the number of ADAR3000 or ADAR3001 used in the beamforming network allows the antenna to scale to an unlimited number of beams and elements.
The ADAR3000 and ADAR3001 are on a low power process that is also suitable for space missions. The process itself is radiation tolerant such that the ADAR3000 and ADAR3001 are suitable for not only LEO missions but also GEO missions. To address the more aggressive cost targets for LEO constellations, ADI has developed a portfolio of commercial space parts that are screened to either a commercial space low (CSL) flow or commercial space high (CSH) flow. The ADAR3000 and ADAR3001 are available in both commercial space low and commercial space high flows to address both LEO and GEO requirements.
Not only is the ADAR3000 and ADAR3001 suitable for satellite applications but has a unique feature where each BFIC can be used as either a transmitter or receiver. The digital definition allows the registers to load the beam weights in the required order to support the device as a receive BFIC (elements to beams) or a transmit BFIC (beam to elements). Thus, multi-beam ground and user terminals can be realized with this low power device.
To conclude, the ADAR3000 and ADAR3001 are the industry’s first commercially available multi-beam BFICs that can support both satellite beamforming antennas as well as terminal applications. Its low power per channel, high level of integration, unique digital capabilities and commercial space screening flows provides a unique solution for the expanding LEO constellations being deployed as well as supporting more traditional GEO satellites.
See also collaboration annoucement with MDA: https://www.analog.com/en/about-adi/news-room/press-releases/2021/4-7-2021-analog-devices-mda-collaborate-to-provide-electronic-beam-forming-technology.html