Figure 1
From: Realizing Tunable Inverse and Normal Doppler Shifts in Reconfigurable RF Metamaterials
Illustration of the experimental set-up used to demonstrate inverse and normal Doppler shifts.
a, The whole set-up used to test Doppler shifts. V(xi,t)(i = 1,2…14) are the bias voltages provided to the CRLH TL units. Two different colors on the reflective boundary controller stand for two different voltages, which leads to the different characteristics of the corresponding units of the transmission line. The units of the transmission line in gray lie in passband (either right-handed or left-handed), while the CRLH TL units in brown are set in band gap. The reflective boundary at the interface between the two kinds of units can move at the velocity of vs by switching the bias voltages supplied by the external controlling circuit. b, Schematic of the unit of the CRLH TL. The reflective boundary controller provides the bias voltage V(xi,t) to the varactors through a ferrite bead which prevents the incident wave propagating from the CRLH TL to the controller.
