Resonant length of longitudinal slots and validity of circuit representation: theory and experiment

The design of waveguide-fed longitudinal slot arrays requires input data on self-admittance versus slot offset and length. Experimental determination of this data is costly and ultimately not sufficiently accurate. Method-of-moments solutions now can provide this data cheaply and with greater inherent accuracy. This is demonstrated by comparing theory to carefully performed experiments. The theory is also used to examine the validity of the equivalent shunt element representation of the slot.