Electrically tunable split-ring resonators at microwave frequencies based on barium-strontium-titanate thick films

Microstrip Transmission Line Loaded by Split-Ring Resonators Tuned by Ferroelectric Thin Film

“…The corresponding tuneability is around 7% for a bias voltage variation of 30 Volts. Comparable tuneability values (12%) was recently published in the literature [11] with rejection level of the same order of magnitude. However, it should be noticed that the bias voltage was 140 Volts for this reference and hence four times Figure 7.…”

“…Basically, a SRR can be described by a L-C equivalent circuit and thus the resonance frequency can be tuned by the capacitance value. So far, the tuneability, based on this principle, was demonstrated mainly by means of varactor diodes [9,10] and recently by using uniform ferroelectric films [11] with a bias in excess of 140 Volts. In this paper, we address the possibility to tune the SRR frequency response with Ba 0.5 Sr 0.5 TiO 3 controlled by a dc electric field under moderate voltages.…”

Tunable magnetic metamaterial based multi-split-ring resonator (MSRR) using MEMS switch components

“…Recently, there have been some efforts to realize tunable capacitance of the resonator structure by mechanical ways as well as appropriately combined ways of devices or materials, such as, mechanical tunability (Wang et al 2008(Wang et al , 2009, loaded passive and active devices tunability (Smith et al 2000;Wang et al 2007), voltage or thermal controlling ferroelectric material tunability (Gil et al 2009;Ozbay et al 2007), magnetic or thermal controlling liquid crystal (LC) material tunability ), electrical, magnetostatic and optical controlling semiconductor materials tunability (Han et al 2008;Shen et al 2009). These methods can make metamaterials work at a variable frequency range instead of a fixed frequency range determined by their geometry and realize tunable metamaterials.…”

Magneto-inductive phase-shifters and interferometers

“…Tunable resonant elements based mainly on varactors have been developed for SRR and other media [21][22][23][24][25], and have been used to construct tunable phase shifters [26][27][28][29][30][31]. There has also been interest in broadband phase shifter designs [32][33][34].…”