A microstrip antenna produces a multiband response due to various modifications done to the patch. These modifications include adding multiple stubs on the patch, or cutting multiple slots on the patch or using combination of stubs and slots. In this paper, an analysis to study the multi-band response in stub loaded half U-slot and rectangular cut rectangular microstrip antenna is presented. The paper begins with an analysis of half U slot cut and rectangular slot cut antenna which yields a triple band response. Here variations in current distribution and resonance frequencies are studied with respect to variation in length of the rectangular slot and then the position with half U slot cut dimensions kept constant. The paper then moves on to study the effect of variation of half U slot cut dimensions with rectangular slot length and position kept constant. Lastly the analysis of adding a stub on to this dual slot configuration is explained in detail. The proposed analysis gives an insight into the functioning of slot cut stub loaded multi-band rectangular microstrip antennas and will help to design them at desired frequencies.

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Rectangular microstrip antenna Multi-band microstrip antenna Rectangular slot Half U-slot Open circuit stub Higher order mode