Synthesis of a 4 <formula formulatype="inline"> <tex Notation="TeX">$\times$</tex></formula> 4 Walsh–Hadamard Transformer Using Long-Period Waveguide Grating Arrays

Synthesis of a 4 - 4 Walsh–Hadamard Transformer Using Long-Period Waveguide Grating Arrays | IEEE Journals & Magazine | IEEE Xplore