Ad-A-Beam™ Adaptive Analog Beamforming
There are really two issues here. The first is the fact that Linear Signal, though expert in digital beamforming arrays and array feeds, focuses on analog beamforming. The second is that our analog signal processing architecture allows our beamforming to be adaptive—able to track and null dynamically.
Analog vs Digital
We use analog, because our focus is on low cost beamforming solutions—beamforming antennas that can compete on price with reflector based solutions. Analog delivers a far lower cost than digital in broadband, multi-element/multi-beam array antennas such as those required for satellite communications.
As an example. A digital array for a satellite television on the move application may require 800 antenna elements and may need to process 500Mhz or roughly 1Gbps per element. This is 800Gbps of signal processing. This antenna is just not feasible to build for most commercial applications, and won’t be for more than a decade or two.
Integrating Analog Beamforming Parts on Silicon
Of course, though analog is not as expensive, it is still prohibitively expensive. This is due to the cost of the discrete or unintegrated analog parts. The satellite television on the move array above would require 800 phase shifters at about $40/each for $32,000. Then there are the other parts in equal numbers.
What is needed is a highly integrated, low cost silicon solution. So, Linear Signal offers its integrated Ad-A-Beam beamforming chips that combine some 28 discrete components into one small chip—a chip developed with a low cost silicon process (SiGe). Integrated analog beamforming becomes affordable.
Adaptive Analog Beamforming
Of course, the reason there is even a discussion about digital beamforming is that it is highly preferable to analog in flexibility. You have any number of options in your beamformed solution when working with digital.
Linear Signal’s proprietary analog architecture offers digitally controlled phase and amplitude control of each beamforming channel, which offers the ability to perform adaptive analog beamforming. This offers some of the advantages common to digital beamforming, while remaining in the analog domain.
Another note on our proprietary analog architecture . . . Because there is amplitude shift as well as phase shift, the same chips needed for an electronically steered array can be used for an electronically steered feed or PAF. This dual use allows for greater volume in the chipset and therefore better costing.
Yet another note. Digital beamforming can be used on the combined analog beams formed with our analog beamforming process. This allows Ad-A-Beam chips to bear the brunt of the cost question while keeping full digital beamforming flexibility.