Over the recent years, a large number of broadband satellite systems have been launched into low earth orbit (LEO), connecting people across the globe. Flat-panel antennas are especially attractive for the LEO satellites because of their tracking ability & a much simpler process of installation.
Ku- & Ka-Band satellite UTs require some of the most highly directive antennas to close RF links with the satellites that are continuously orbiting at altitudes ranging from a few hundred to thousand kilometres above the surface of the earth. Fixed parabolic reflectors are widely used for the conventional geostationary (GEO) satellite systems, which don’t necessitate tracking because the satellite’s position that is relative to the user terminal has a fixed period of time. LEO constellations, on the other hand, require tracking & satellite-to-satellite handovers to maintain the connectivity. These features, incorporated with the cumbersome mechanics & form factors, make parabolic antennas less attractive for the LEO systems.
Some of the top-notch flat panel antennas and their techniques that are prevailing in the market are as follows:
a.)ESA ANTENNA (Electronically Steered Antenna)
In the case of LEO systems, one of the most suitable alternatives to the conventional dish antenna is an ESA, which is also known as a phased array antenna. An ESA inculcates an array of many sub-wavelength radiating antenna elements, whose relative phases are controlled in such a manner that the overall beam generated from the array radiates in a particular direction because of constructive & destructive interference between the individual elements.
Some of the pivotal information about the ESA ANTENNA are:
- The overall procedure of constructing a concentrated beam by using the phased array antennas is known as beamforming.
- The strength of the overall beam entirely depends on the no of coherent radiating elements & the array configuration in the antenna. It also has a higher number of radiating elements that contributes to a narrower & more powerful main lobe integrated with smaller & less powerful side lobes.
b.) ANALOG BEAMFORMING
Analog beamforming is regarded as the most basic technique for the formation of flat panel antennas. It generally uses a single RF chain that efficiently connects each antenna element with the amplifiers & phase shifters, followed by the splitters or combiners. The phase shifters, combiners and splitters are implemented by using analogue hardware. Beam shape & direction are controlled collectively by digitally adjusting the phase shifters along the RF paths.
Analog beamforming is regarded as more cost-effective & less complex as compared to digital beamforming. However, it can effectively support only a single beam at a time, as it is restricted to the same signal for each of the antenna elements. The occurrence of Multi-beam transmission is possible, but it is tedious & complex. The antenna array is regarded as a full-duplex (simultaneous transmission & reception) and single aperture that efficiently uses frequency multiplexing with the help of independently controlled transmit & receive channels for each of the radiating elements.
Although the digital beamforming is pretty much similar to analogue beamforming, it differs as each antenna element has a dedicated RF-to-digital signal & path rather than that of a single common RF chain.
c.) VICTS ANTENNA
A VICTS antenna is regarded as a type of passive flat panel aperture antenna that consists of multiple stacked disks that rotate mechanically around a single axis to achieve azimuth & elevation beam scanning. The most basic type of VICTS antenna uses two disks, an upper disk & a lower disk.
The upper disk consists of long parallel slits cut through it that allow the electromagnetic waves to propagate effectively without any resistance. These slits are regarded as the radiating elements of the aperture & are also known as continuous transverse stubs.
The lower disk has one or more line sources that produce electromagnetic waves. The space provided between the upper & the lower disk acts like that of a planar waveguide structure that carries the electromagnetic waves that feed the radiation.
d.) HYBRID BEAMFORMING
Hybrid Beamforming effectively combines the various aspects of analogue & digital beamforming. It uses digitally controlled RF chains integrated with analogue splitters & analogue phase shifters. Fewer RF chains are thus needed, which lowers the overall power consumption. The number of antennas that are widely used in hybrid beamforming is comparatively higher as compared to the number of A/D converters, which results in a less number of supported data streams. With that being said, hybrid beamforming is regarded as a reasonably priced alternative to that digital beamforming as it consumes much less power while still allowing the process of multi-stream transmission.
Thus, due to the introduction of these sorts of techniques in the above mentioned flat panel antennas, the market is expected to accelerate at a rapid pace in the future with a robust CAGR. On the other hand, these technologies are likely to change the entire market outlook in due course of time, thereby contributing efficiently to the market growth worldwide.