Wideband slow phase loaded inductor-composite right/left-handed transmission line for compact UWB power divider

This article introduces analysis of the new configuration; inductor loaded left-handed composite right-/left-handed transmission line ((L-CRLH TL). Compared to conventional CRLH and dual CRLH, this configuration has the advantage of very slow phase (almost constant) and nonlinear propagation coefficient which enables it to be very effective in designing compact size and ultra-wideband (UWB) microwave components. The theoretical and circuit model of the L-CRLH TL is discussed. As an application, a compact UWB (3.1-10.6 GHz) L-CRLH power divider is designed using only one L-CRLH cell with size of 2.7 x 8.6 mm(2) whereas the whole power divider photoprint is 12.14 x 18.83 mm(2). The size is 58.5% smaller compared to the conventional narrow band T-junction power divider designed at the mid frequency. The results reveal good insertion losses (3.2 +/- 0.2 dB for both S-21 and S-31), and good return losses (better than 10 dB within the passband).