Diseño de un modulador vectorial basado en suma de vectores para aplicaciones de antenas activas en la banda de 17,8 a 20,2 GHz

Abstract

El objetivo principal del presente Trabajo Fin de Grado es el dise~no de un phase shifter o modulador vectorial para el rango de frecuencia de 17.8 GHz a 20.2 GHz, usando para ello, la tecnolog a SiGe BiCMOS de 130 nm de IHP. El desfasador se dise~nar a para antenas de tipo phased array. Este tipo de antenas est an cada d a m as demandadas ya que son capaces de suplir los inconvenientes que presentan las antenas parab olicas a la hora de implementarse en aplicaciones m oviles o que requieran de un per l de antena m as bajo. Inicialmente, se ha realizado un estudio de los desfasadores programables y de las antenas phased array, tras el cual se ha llevado a cabo el dise~no basado en un ampli - cador diferencial con la topolog a de un cascodo. Para el dise~no a nivel de esquem atico, tanto del ampli cador diferencial como del resto de componentes del desfasador (Quadrature All-Pass Filter, Digital-Analogic Converters, switches, etc) se ha usado el software Advanced Design System de la compa~n a Keysight Technologies. Cada parte del modulador vectorial se ha dise~nado e implementado a la vez que se han ido realizando simulaciones para adaptar el circuito y comprobar su correcto funcionamiento. Una vez completado el dise~no inicial, se han sustituido los componentes ideales del circuito (resistencias, condensadores y bobinas) por sus equivalentes reales de la tecnolog a con la que se ha trabajado. Finalmente, se ha realizado el dise~no del phase shifter capaz de generar cambios de fase entre 0° y 360° con saltos de 5:625°.

The main purpose of this work is the design of a phase shifter, also known as vector modulator, for the frequency range 17,8 GHz to 20,2 GHz. For that purpose, SiGe BiCMOS 130 nm technology developed by IHP will be used. The phase shifter has been designed for phased array antennas. The demand for this kind of antennas increases by the day due to their capacity to solve the drawbacks of dishes antennas when implemented in moving systems and when a lower antenna pro le is needed. Initially, a study of programmable phase shifters and phased array antennas was carried out, after which the design based on a di erential ampli er was made. For the schematic design of the ampli er and the other components of the phase shifter( Quadrature All-Pass Filter, Digital-Analogic Converters, switches...) the software Advanced Design System, developed by Keysight Techonolgies, was used. Each part of the vector modulator was designed and implemented while simulations were run to match the circuit and check the proper functioning at the same time. Once the design was completed, the ideal components of the circuit (resistors, capacitors and inductors) were replaced by their real equivalents of the selected technology. Finally, the design of the phase shifter capable of generating phase shifts between 0° and 360° with steps of 5:625° has been nished.