This paper presents a new type of microstrip composite right/left handed transmission line (CRLH TL) constructed by Minkowski loop shaped complementary split ring resonators (M-CSRRs) and interdigital capacitor in the upper metal level. Transmission behavior of novel CRLH TL is researched by EM simulation as well as electrical simulation and validated by experimental measurement. By using the CRLH TL effect, a broadband quadrature power splitter (QPS) is designed and fabricated. The simulation and tested results show that within the frequency band range of 2.7-6.6 GHz, all return losses are greater than 10dB while the isolation is better than 15dB, phase non-equilibrium and transmission magnitude difference between two outputs are less than 90°±7° and 0.8 dB respectively，thus the relative bandwidth reaches 83.9%.