Low noise and high gain dual-band active band-pass filter with GaAs MESFET using CRLH metamaterial

Abstract

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 <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> =1.23 GHz and f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> =1.63 GHz, where the phase slop characteristics of the response are chosen as f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> =-90° and f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> = -270°. 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.