This Thesis is focused in the work developed by the author in the frame of the MAGIC collaboration, mainly in high frequency electronics for MAGIC I and II Cherenkov Telescopes. The main achievements during this PhD period have been the following: Design of low noise, low jitter pulse generators for te test of the analog transmission of the telescopes. Based in previous designs, modelling and construction of a prototype of pulsed light emmiter based on high speed LEDs. This prototype generates signals similar to the ones received by the telescope, with the purpose of testing the camera pixels. Desing, production and test of broadband (up to 1 GHz) low noise and high dynamic range amplifiers. Setup of a testbench for time response and single photoelectron counting of various state of the art photodetectors.