Analysis of open-end slot-line for examining radiation mechanisms of constant width and tapered slot antennas

Constant width and tapered slot antennas have been generally categorised as travelling-wave antennas without referring to their exact radiation mechanisms. This paper examines current distribution of an open-end slot-line of a few wavelengths long and establishes that the radiation from these antennas can be caused by discontinuities as well as by leaky modes. The results reported widen understanding of the radiation mechanisms and are significant in the development of better approximate models for the design of efficient well-behaved constant width and tapered slot antennas.