Slot Array Antennas at V-band based on Inverted Microstrip Gap Waveguide

Licentiate thesis, 2017

Recently, gap waveguide technology is introduced as a proper guiding structure for millimeter-systems. The conception of gap waveguide technology can be modeled for theoretical analysis by two parallel plates, a top perfect electric conductor layer and a bottom perfect magnetic conductor layer. This structure stops all modes propagating in all directions except for a quasi-TEM mode when the gap between perfect electric conductor and perfect magnetic conductor plates is smaller than quarter wavelength at an operating frequency. Until now there are already four different visions of this novel conception-groove, ridge, inverted microstrip and microstrip ridge gap waveguides. Among those four structures, the inverted microstrip gap waveguide has same obvious advantages. First of all, it has a uniform bed of nails while the others do not. This uniform pin structure makes the fabrication much easier and cheaper. Secondly, fabrication of microstrip circuitry on PCB by etching is accurate and very low cost. In addition, theories and design principles of microstrip technologies are very well-developed. Therefore, my work in this Lic. thesis is focusing on the theory of inverted microstrip gap waveguide and its applications on millimeter wave array antenna design.