Miniaturised and multilayer Wilkinson divider and balun for microwave and millimeter-wave applications

Two miniaturised passive circuits, lumped-distributed Wilkinson divider and the all-ports matched impedance transformer based on Marchand balun are proposed. Applying a shunted input capacitor and RC isolation network, the Wilkinson divider size is arbitrarily reduced. For the all-ports matched Marchand balun, a proposed isolation network has been applied to reduce the whole size. These two circuits were designed and simulated based on 2.5D electromagnetic simulation software package. Excellent results of X-band lumped-distributed Wilkinson and W-band CPW balun were achieved.