Table 2. The SNR obtained from different kind of surface resonators.

Temperature (K)	d (mm)	The HTS surface resonator	The QD surface resonator	The copper surface resonator
T = 77 K	ds = 5 mm	SNR = 200		SNR = 88
T = 300 K	ds = 5 mm			SNR = 52
T = 300 K	D = 0 mm		SNR = 139
T = 300 K	D = 5 mm		SNR = 86

The distance between the HTS surface resonator/copper surface resonator and the phantom is d, while the distance between the QD surface resonator and the phantom is D.