A New Filtering Patch Crossover With Improved Stopband Rejection Range and Reduced Size

This letter presents a new and straightforward design method for a patch filtering crossover that features an improved stopband performance and reduced size. A square patch with orthogonal mode TM<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> and TM<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">01</sub> resonances is positioned at the intersection, while four half-mode patches with half-TM<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> mode resonances are arranged around the square patch. Isolation between channels is achieved through mode cancellation. Due to the unique excitation of the half-mode patch and the interweaving of spurious modes, the −20-dB stopband range has been extended to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2.98f_{0}$</tex-math> </inline-formula>. A prototype has been designed, fabricated, and measured to validate the proposal, demonstrating good consistency between the simulated and measured results.