Discriminador de microondas reconfigurable de 2 bits con interruptores RF-MEMS

Abstract

This project describes the operation, requirements and design of a microwave discriminator with 2 ports, core component in a 2-bit frequency detection system. The reconfigurable frequency detection circuit allows the identification of any unknown signal in the range of frequency between 9 to 11 GHz (X-Band). The microwave discriminator is the component that performs this function within the receiver. This receiver is implemented with the combination of coplanar technology and microelectromechanical radiofrequency systems (RF-MEMS). The discriminator is composed by three transmissions lines: the first reference line, with a "λ/2" wavelength and two delay lines, with "λ", "3λ/2" wavelengths, which are the fundamental lines for the discriminator design. The combinations of these lines are connected to a power divider at the input and a power combiner at the output. All these components are integrated on a quartz substrate. The power divider is made with coplanar transmission lines (CPW) and a Wilkinson type divider with two stages of derivation is used. The function of the divider is to distribute the power received by the discriminator through its input port equally between its two output ports, in which the reference line and the delay lines will be connected. The Wilkinson-type splitter also acts as a power combiner at the output of the lines. The lines are switched through an SPDT system, by means of an RF-MEMS switch, which provides re-configurability and will allow to change the states in the design. The switch is modeled as RLC circuits for simulations. This switch and delay lines are the main component of the microwave discriminator. All the design and simulations of this project was done with ADS / Momentum software, obtaining satisfactory results, since it allowed integrating all the components of the discriminator to obtain later the identification of the bits for frequency identification by means of a reconfigurable RF-Mems circuit.