“…In other words, rather than embedding the electrically small resonant metallic inclusions into the host material, the left handed feature can also be realized with low loss by periodic loading of conventional microstrip transmission lines with series capacitors and shunt inductors in planar microwave technology [Caloz & Itoh, 2005;Eleftheriades & Balmain, 2005]. Many microwave circuits have been implemented by using this strategy such as compact broadband couplers [Nguyen & Caloz 2007], broadband phase shifters [Eleftheriades & Balmain, 2005], compact wideband filters [Gil et al, 2007], compact resonant antennas [Lee et al, 2005[Lee et al, , 2006Schüßler et al, 2004;Sanada et al 2004].…”