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Artificial transmission lines based on lattice network unit cells can mimic the behavior of actual metamaterial transmission lines without introducing any stopband, as opposite to their conventional counterparts based on T- or II-network unit cells, which can be balanced to suppress the stopbands in the transitions from left- to right-handed bands, but will always present stopbands in the right-handed-to left-handed-band transitions. The aim of this paper is twofold. First, the general properties of lattice network unit cells are discussed using simple circuit theory concepts. As a result, a systematic classification of all possible balanced lattice network-based artificial transmission line unit cells is described. Second, a novel multiband lattice network-based unit cell is presented. The proposed unit cell is made up of a coupled-microstrip section in a host microstrip and requires neither air bridges nor via-holes. Coupled lines have already been used to obtain composite right-/left-handed transmission lines, but a solution, based on wiggly lines, is given in this paper to the problem caused by the different even- and odd-mode phase velocities. As a result, the wideband capabilities of the artificial transmission line are fully exploited, as the theoretical and experimental results corroborate.