Modeling of a Conical Antenna Applied in a Waveguide Device

This work presents a study about impedance matching in a microwave device formed by the junction of waveguides. These transitions are characterized by a probe antenna that ensures the electromagnetic field coupling between waveguides of different geometries. The modeling for this antenna is based on the theory of the electrical transmission line. In this way, we estimate the input impedance of a conical antenna that feeds a coaxial waveguide. This theoretical approach allows obtaining the characteristic parameters, length and angle, of the conical antenna in a practical way. In order to validate the estimated parameters, we used COMSOL software to build the transition geometry and to simulate the waveguide device electrical response. The simulation results showed an improvement in the broadband response and impedance matching using a conical antenna as a field coupling probe inside the waveguide device.