Compact right-handed (RH) and left-handed (LH) lattice-network unit cells implemented in monolayer printed circuits

The implementation of right-handed (RH) and left-handed (LH) X-type lattice network structures in monolayer printed circuits is investigated in this work. The resulting structures, based on semi-lumped planar elements, are compact, exhibit a broad bandwidth, and can be easily fabricated in conventional microwave substrates since only two metal layers (plus via holes) are required. This latter aspect is the main advantage of the proposed approach as compared to other existing lattice network structures. The circuit model of the structures, including parasitics, is proposed and compared to full wave electromagnetic simulations. Finally, a prototype device has been fabricated, where the baluns for measurement have been added to the input and output ports. Due to the broadband operation, these structures can be of interest for the design of compact enhanced bandwidth and multiband components with superior performance as compared to those based on conventional Π- or T-type artificial lines.