Dual-band distributed amplifier with new D-CRLH transmission line

A high-gain dual-band distributed amplifier (DBDA) based on the dual-composite right/left handed transmission line (D-CRLH TL) is presented. Both forward and reverse gains of the DAs are simultaneously available, when their conventional TLs are replaced by the metamaterial TLs. To improve the performance of the DBDA, a new D-CRLH with a narrower stop band than the conventional D-CRLH is proposed. This leads to enhanced bandwidth for the proposed DBDA. In addition, the introduced TL increases the reverse power gain of DBDA, by decreasing the wave attenuation coefficients at this band. The results show that the DBDA achieves 31.5 +/- 1.4 dB forward power gain with a 3 dB bandwidth of 2 GHz (from 0.8 to 2.8 GHz) and 31.5 +/- 1.5 dB reverse power gain with a 3 dB bandwidth of 2.5 GHz (from 5 to 7.5 GHz). The good agreement between measurement and simulation results confirms the accuracy of the design method.