A stable low noise and high gain dual‐band active band‐pass filter with GaAs‐MESFET using CRLH metamaterial

Abstract

In this article, a stable low noise and high gain dual‐band active bandpass filter (BPF) with GaAs‐metal‐semiconductor field effect transistor (MESFET) using composite right‐/left‐handed (CRLH) metamaterial is presented. The CRLH approach in a microstrip structure is applied to develop a dual‐band BPF using an amplifier circuit with two arbitrary frequency bands. The two center frequencies of the filter are then chosen as ω1 = 1.23 GHz and ω2 = 1.63 GHz, where the phase slope characteristics of the response are chosen as −90° and −270° at frequencies of ω1 and ω2, respectively. The experimental results show gain values of 7.82 and 7.03 dB and the return losses of −15.1 and −10.1 dB with bandwidth of 55 (4.4%) and 105 MHz (6.4%) at the center frequencies of 1.22 and 1.61 GHz, respectively. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1985–1988, 2014

Compact low noise amplifier with high stable gain using distributed CRLH metamaterial

“…Figure shows the experimental results for the phase response slope in the CRLH unit‐cell at LNA. The phase of this artificial CRLH unit‐cell can be represented as where ϕ RH and ϕ LH are the phase responses of the RH and LH sections and N and f are the number of CRLH unit‐cells and operating frequencies, respectively. The operating frequencyis 2.0 GHz.…”

“…Figure also shows the L Li ( i = 1, 2) and C Li ( i = 1, 2) as shunt inductors and series capacitors corresponding to the CRLH unit‐cell, respectively and L L and C L can then be obtained from Ref. , which are given as …”