Abstract: A microstrip transmission line structure a series of connected microstrip strip sections having different widths disposed on an outside layer of a unitized multilayer circuit structure and forming a microstrip line, respective ground planes for each of the strip sections formed between insulating layers of the untilized multilayer circuit structure and respectively spaced from the associated strip sections to provide a substantially constant impedance along the length of the microstrip line, and a plurality of conductive vias for electrically interconnecting the respective ground planes.

Abstract: Stripline shielding structures for stripline conductors implemented in unitized multilayer circuit structures are disclosed. The stripline structures generally include a lower ground plane below the stripline conductor, one or more embedded ground planes above the stripline conductor, and conductive elements laterally spaced from the stripline conductor for electrically connecting the ground planes. Resistive layers may be included above the embedded ground plane(s) for additional shielding.