Diseño de una etapa amplificadora para un integrador de señales de banda ancha en un sistema híbrido coherente

In the last few years free-space laser communications have become a feasible and high-bandwidth wireless alternative to fiber optic cabling and radio frequency (RF) systems due to its extremely robustness against interference and the advantage of working with optical wavelengths in compare to the RF spectral band (flexibility, low loss, smaller size and greater bandwidth). Even though RF systems are nowadays still used in multiple applications the increasing data-rate and bandwidth need, become clear a change to Free Space Communications (FSO). FSO is an optical communication technology where free space acts as a medium between transceivers that should be in line-of-sight (LOS) in order to achieve a successful transmission of optical signal. However, in free-space optical communication links there are also some unavoidable environmental challenges. One of this, atmospheric turbulence causes fluctuations in both the amplitude and the phase of the received light signal and also induces fading to the wave front, impairing link performance. The compensation of transmission impairments can be performed using spatial diversity techniques. In order to mitigate this fluctuations, it is necessary to use a system with a receiver array formed by a number of detectors, where each detector will observe a different section of the optical beam since these fluctuations can cause the signal-to-noise (SNR) that arrives to the receiver is not good enough to retrieve the information. In a previous Treball Final de Grau (TFG) it was proposed a solution for the signal fading caused by atmospheric turbulence by using a hybrid system (optical and RF) formed by an array of four sub-apertures, which was able to compensate the atmospheric turbulence with signals up to 2 GHz bandwidth using comercial hardware. This project aims to deisgn and manufacture a prototype of the amplification stage of the system described above, working in a bandwidth between 1.45 GHz and 2.45 GHz. Theese prototypes will be measured and compared with the commercial evaluation boards. Finally, an integrated design on a single board including all the manufactured hardware in this project will be proposed.