Robust stability characterizations of active metamaterials with non-Foster loads<xref rid="cpb_27_2_028102_fn1" ref-type="fn">*</xref><fn id="cpb_27_2_028102_fn1"><label>*</label><p>Project supported by the National Natural Science Foundation of China (Grant No. 61701349), the Natural Science Foundation of Shandong Province, China (Grant Nos. ZR2017QF012 and ZR2017MF042), and the Program for the Top Young Innovative Talents, China (Grant No. Q1313-03).</p></fn>

Robust stability characterizations of active metamaterials with non-Foster loads**

Project supported by the National Natural Science Foundation of China (Grant No. 61701349), the Natural Science Foundation of Shandong Province, China (Grant Nos. ZR2017QF012 and ZR2017MF042), and the Program for the Top Young Innovative Talents, China (Grant No. Q1313-03).

Fan Yi-Feng^{1, 1}, Sun Yong-Zhi^{1, 2, †}

(color online) (a) Nyquist contours of the proposed medium for the disturbed models, as compared with the result for the undisturbed model. (b) Magnified part of Nyquist contours around the −1 point. Disturbed model 1 (blue line) corresponds to the system with a normalized RTD disturbance of +10%, while disturbed model 2 (red line) corresponds to the case of −10%.