Load impedances of complex slotline terminations

Single slotline has gained new interest due to application in uniplanar circuits, antennas or active radiators, all these including slotline short circuits or even more complex terminations. This paper gives a new approach to calculation of reflection coefficient and load impedances of such terminations using the spectral domain method. Furthermore, slotline resonators are analysed in the similar way, and their complex resonant frequency is calculated. That is used in an alternative determination of the slotline load impedance by application of the transmission line theory. Computed results compare well with experiment. Closed-form formulae for CAD purposes are proposed.