Figure 3
The digital sensor design and assembly. (a) The block diagram of the digital circuit to detect the B1/RF field via an inductor, and convert it to a rail to rail square wave, which further down converted from 64 MHz to 10 kHz via an asynchronous counter and monostable multivibrator with duty cycle of >90%. A representative wave diagram is shown at each point of the circuit when an RF pulse is picked up by the inductor during transmission sequence (b) The circuit diagram of the switching matrix connected to the parallel wires of the metamaterial.(c) The respective assembled PCB (The sensing inductor and battery are not shown in the picture) for digital circuits and (d) The implemented PCB for switch matrix with a common anode and cathode bias line. RF Choke Inductors are connected to the anode and cathode of each diode to isolate them from each other at higher frequency (64 MHz).
