Characteristics ofBilaterally Metal-Loaded Tr- PlateStrip Line Filter atMillimeter-Wavel ength

Although dielectric-supported tri-plate strip lines are usually usedatcentimeter frequencies, theysuffer fromalotof transmission lossduetotheir roughunder-surfaces ofmetal strips. And moreover, undesired radiation occursincircuit elements suchasaband-pass filter duetotheir asymmetrical structures. Inthispaper, we solved thisproblembymaking center conductors onbothsurfaces ofthedielectric substrate and designed athree-pole 0.1dBripple Chebyshev band-pass filter by using suchguiding structure, termedbilaterally metal-loaded tri- platestripline.It was obviousthatthetransmission characteristics ofthebilaterally metal-loaded tri-plate strip line wasunaffected bytheskineffect oftheundersurface ofthe metalstrips, because thetwocenter conductors werethesame voltage, andhence, thelow-loss nature. Insertion lossofthe designed band-pass filter wassmall duetoitslow-loss nature as wellasno-undesired radiation. Keywords-component; Printed transmission line, Band-pass Filter, Tri-plate strip transmission line, Millimeter-waves