The design of high gain substrate integrated waveguide antennas

The design and implementation of circularly polarized substrate integrated waveguide (SIW) antenna in X Band is presented in this paper. The substrate integrated waveguides represents the family of substrate integrated circuits which is planar in nature and used for the transmission of electromagnetic energy. In this paper the design techniques for substrate integrated waveguide using slots with the integration of microstrip are presented, which emphasis the broad perspective of the substrate integrated waveguide in circular polarization. The design has simulated in HFSS Software. From the simulation results, it is observed that gain has increased in SIW structure with slots for circular polarization as compared to SIW structure without slots.

I. Introduction

The transmission of electromagnetic energy is accomplished conventionally by two conductor lines such as parallel line, coaxial cables and two wire cables. The energy will not travel through normal electrical wire without great losses. It can encounter large losses such as radiation loss, copper loss, dielectric loss and skin effect. Also the transmission lines encounters difficulty in interconnecting with the planar circuits due to its non-planar nature. Waveguides are the better option for the transmission of electromagnetic energy in comparison with transmission lines. Since waveguides are non - planar and bulky, substrate integrated waveguide can be a substitute option for the transmission of the electromagnetic energy. But it has the benefits of conventional waveguides such as high power handling capability and high quality factor. In the transmission line the wavelength of the signal in the transmission line is comparable to the transverse size of the line so some complicated excitations are occurred in transmission lines.