Projecte fet en col.laboració amb el centre Vrije Universiteit Brussel

In this master degree project a Synthetic Aperture Radar (SAR) transmitter is designed and realized. This transmitter will be used in the Signal Theory and Communications lab of Universitat Politècnica de Catalunya as a test transmitter because the actual transmitters, which are two satellites from the European Space Agency, only provide a few seconds of testing every few weeks. This is not su cient to continuously improve the sophisticated receiver subsystems. It was mainly focussed on the design, layout and building of the analog microwave subsystems but also some programming skills were necessary to generate the required input signal. By means of two synchronized direct digital synthesizers, two linearly frequency sweeping signals (chirps) at low-frequency band (base band) are generated and two mixers upconvert these signals to a high-frequency band around a carrier at 5.3 GHz. The carriers are provided by a quadrature hybrid, which splits the high-frequent sine wave from the local oscillator in an in-phase signal and a signal 90 degrees shifted in phase to the latter one (quadrature signal). Both outputs from the mixers are recombined by a power combiner, ltered and ampli ed by a low-noise ampli er and a power ampli er to obtain the required test signal. The testing of the transmitter was a great success in which theory went hand in hand with practice. The realization of this project will be one of the required assets for further groundbreaking developments in the SAR research domain.