Coupled-Combline Structures for Use in M.I.C.´s

Passive M.I.C. components made of coupled-comb line sections were built by empirical optimization, but a theoretical approach for designing such devices has not been available so far. Making use of coupled-transmission-line techniques and the Bloch-wave formalism for periodic structures, a method for coupled combline analysis is developed in the present paper. The method is exact under the homogeneous-dielectric assumption and yields excellent approximation for the microstrip case. The analysis is carried out by explicit formulae, ensuring high efficiency when numerically implemented. Thus the design problem can be solved by straightforward optimization.