Low Noise and High Gain Dual-band Active Band-pass Filter with GaAs MESFET Using CRLH Metamaterial

In this paper, a low noise and high gain dual-band active bandpass filter (BPF) with GaAs MESFET using the CRLH (Composite Right/Left-Handed) metamaterial is presented. The CRLH is applied to develop a dual-band BPF using an amplifier circuit with two arbitrary frequency bands. Then, the two center frequencies of the filter are chosen as f(1)=1.23 GHz and f(2)=1.63 GHz, where the phase slop characteristics of the response are chosen as f(1)=-90 degrees and f(2)= -270 degrees. The experimental results are gain value of 7.82 dB and 7.03 dB and the return losses of -15.1 dB and -10.1 dB with bandwidth of 55 MHz (4.4 %) and 105 MHz (6.4 %) at the center frequencies of 1.22 GHz and 1.61 GHz, respectively.