Study of Dielectric Loss and Conductor Loss among Microstrip, covered Microstrip and inverted Microstrip Gap Waveguide utilizing variational Method in Millimeter Waves

In this paper, the classic variational method is applied for newly introduced inverted microstrip gap waveguide. Then, the dielectric losses and the conductor losses among the microstrip, covered microstrip and inverted microstrip gap waveguide are analytically calculated based on the variational method in millimeter waves. According to our theory, the dielectric losses of microstrip and covered microstrip gap waveguide are at least 7 times higher than that of inverted microstrip gap waveguide. Therefore, inverted microstrip gap waveguide has huge advantage of low loss in millimeter waves.