Page 27 - EngineerIT December 2022

SPACE SCIENCES

Figure 6: A functional diagram of a discrete HMC798A Ka band user Figure 7: A highly integrated, half-duplex, Ku band, 4-channel
terminal. beamforming IC.

Lowering the cost of user terminals using electronic steerable to become more connected, LEO will
antenna play an important role in 5G by further
Companies are focusing on lowering the cost of deployment of user terminals by enhancing the connectivity of the 3GPP
removing the expensive installation cost traditionally associated with a professional standard from space to rural locations.
contractor who mounts the equipment and locates the satellite position. This is The RFIC integration requirement
achieved by combining the antenna along with all the electronics (for example, phase- on user terminals is becoming more
shifting elements, RFIC UDCs) required to process the communication link in a single challenging and ADI is continuing to
outdoor unit (ODU). The ODU is the antenna array that resides outside the home and develop solutions and roadmap ICs in
is aimed at the sky. An indoor unit (IDU) is connected to the ODU and functions as a this domain. n
traditional router (wired or wireless) to supply internet connectivity to the user (for
example, PC or phone). References
As mentioned earlier, LEO constellations will have many satellites that move in and - Cajaj, Shkelzen. “The Parameters
out of the ground terminal field of view, so it’s far more efficient to use the electronic Comparison of the ‘Starlink’ LEO Satellites
Constellation for Different Orbital Shells.”
steerable antenna (ESA) as it can enable high directivity by electronically steering the Frontiers in Communications and Networks,
transmit and receive beam of energy in the direction of the satellite. Thereby, the best Vol. 2, May 2021.
link is maintained from one satellite to another with near instantaneous switching - Darwish, Tasneem, Gunes Karabulut Kurt,
Halim Yanikomeroglu, Michel Bellemare,
between satellites as the satellites move in and out of view of the user terminal. In fact, and Guillaume Lamontagne. “LEO Satellites
the ESA is almost a requirement when you think of the orbital period and the number of in 5G and Beyond Networks: A Review from
satellites that need to be connected to during the normal course of operation. a Standardisation Perspective.” IEEE Access,
Vol. 10, March 2022.
To address this challenge, ADI has developed the Ku band beam forming integrated - Hall, Brad. “Need More Bandwidth for the
circuit (BFIC) technology. The ADMV4680 is a silicon solution designed for user Ka Band? Here Are Three Options.” Analog
Devices, Inc., November 2017.
terminals, allowing for half-duplex channels to independently control the gain and - King, Yasmine. “New Age of the Commercial
phase of the signal. What is remarkable is that the size of this IC is only 8.2 mm , as Space Satellite.” Analog Devices, Inc.
2
shown in Figure 7.
The core of the development of BFIC technology to minimise overall radio cost is About the Author
system and array expertise. Mechanical assembly and PCB design, which includes stack Donal McCarthy is the marketing and
up and number of layers, are part of the radio cost driver. When the BFIC is developed business development director for the
with the mechanical and PCB designs in mind, a minimum overall radio cost is created. Microwave Communications Group
At ADI, we work closely with customers and have in-house PCB experts to help with this. at Analog Devices in Cork, Ireland. He
In fact, the IC design and final configuration is part of the system trade-off study. holds a B.E.E. degree from the University
Adopting the ESA to both track the LEO satellites and optimise the link speed allows College Cork, an M.B.A. degree from
for low cost setup and typically these are plug and play. The ESA and the migration to Boston College, and a marketing degree
more integrated ODUs are radically simplifying the deployment and lowering the cost of from Irish Management Institute in
the system. The ESA is also enabling a flatter panel and aesthetically pleasing designs. Dublin. Donal held various roles including
It’s worth noting that in the case of highest performance terminal applications, a design engineer at MACOM, field sales
dual parabolic steered antenna is used. In these cases, cost and aesthetics are not a engineer and marketing roles at Hittite,
primary driver and overall performance is the focus. When it comes to consumer and and marketing manager and director
cost-conscious small enterprise solutions, ESA is by far the best way to achieve the roles at ADI.
lowest radio cost while meeting system design goals.
Analog Devices is represented in
Conclusion South Africa by Altron Arrow.
LEO internet connectivity is a new and exciting domain and the race for space is on For more information email
the minds of most governments and internet providers today. As the world continues ccoetzee@arrow.altech.co.za

EngineerIT | December 2022 | 27