A Novel Miniaturized Microstrip-to-Microstrip Transition Using Interdigital Structure Loaded Open Slot

This letter presents a novel miniaturized microstrip-to-microstrip transition. The proposed microstrip-to-microstrip transition consists of two folding open circuit lines and one open slot line loaded interdigital structure. Equivalent model analysis shows that the introduction of the interdigital structure pushes the resonant frequency of the open slot to the lower side. As a result, a microstrip-to-microstrip transition with miniaturized size can be realized easily. Experimental results show that this structure has a very compact size of 0.0194λg2.