Experimental investigation of photonic band gap in one-dimensional photonic crystals with metamaterials

Composite right/left-handed transmission lines with lumped element series capacitors and shunt inductors are used to experimentally realize the one-dimensional photonic crystals composed of single-negative metamaterials. The simulated and experimental results show that a special photonic band gap corresponding to zero-effective-phase (zero-φeffφeff) may appear in the microwave regime. In contrast to the Bragg gap, by changing the length ratio of the two component materials, the width and depth of the zero-φeffφeff gap can be conveniently adjusted while keeping the center frequency constant. Furthermore, the zero-φeffφeff gap vanishes when both the phase-matching and impedance-matching conditions are satisfied simultaneously. These transmission line structures provide a good way for realizing microwave devices based on the zero-φeffφeff gap.

► 1D photonic crystals with metamaterials were investigated experimentally. ► Both Bragg gap and zero-φeffφeff gap were observed in the microwave regime. ► The width and depth of the zero-φeffφeff gap were experimentally adjusted. ► Zero-φeffφeff gap was observed to be close when two match conditions were satisfied.