We propose here a composite right/left handed transmission line constructed by using conductor-backed coplanar strips. In this line, we can easily realize a shunt inductor without via because it has the electric-wall symmetry at the guide center. The left-handed nature is verified by both the finite difference time-domain (FDTD) and the equivalent-circuit calculations. Furthermore, we demonstrate the proposed line can easily satisfy the balanced condition for no band gap between the right-handed and the left-handed modes, and can be applied to a leaky-wave antenna, numerically and experimentally.