Satellite communications (satcom) was once associated with fixed ground stations. But as wireless communications in its various forms truly becomes mobile, more advanced RF/microwave front-ends are being developed that are capable of tracking a satellite’s signals even as a ground terminal is mobile. A great deal of innovative design on these mobile satcom front-ends and antennas has been performed by IMST GmbH from L-band to Ka-band frequencies, using advanced beamforming techniques on compact MMIC devices.
Many of these mobile satcom applications are targeting automotive mobile stations, designed as radio front-ends with transmitters, receivers, and antennas that can be fabricated as miniature, low-cost circuit assemblies for mass production and low cost. At higher frequencies, MMICs based on GaAs substrates, for example, provide the core front-end functions for receive-only and transmit/receive systems.
The GaAs ICs for many of these mobile satcom circuit designs were fabricated in the OMMIC GaAs foundry located in Paris. Modular design approaches were practiced which allowed for the buildup of large antennas consisting of thousands of antenna elements. Satcom radio and antenna front-ends were realized on reliable, low-cost low-temperature-cofired-ceramic (LTCC) circuit materials, which provided final results with high reliability using commercial-off-the-shelf (COTS) devices and components.
This innovative combination of commercial and military architectures, such as the phased-array antennas common to military system systems and the COTS building-block components of commercial products, hints at the possibilities to come for mobile satcom systems in commercial vehicles. Examples of satcom front-end designs developed by IMST and various partners are presented for L-band through Ka-band frequencies, with many different sizes, depending upon wavelengths and operating frequencies. It is clear that satellite communications can be made “vehicle-friendly” and made to fit the needs of different mobile automotive applications.
See “Innovative Antenna Front Ends from L-Band to Ka-Band,” IEEE Antennas & Propagation Magazine, Vol. 59, No. 5, October 2017, p. 116.