Fig. 3: STR sensor's S11 magnitude and phase angle. | npj Biosensing

Fig. 3: STR sensor's S11 magnitude and phase angle.

From: Surface Transmon Resonance (STR): a handheld nanogap biosensor for real-time, label-free molecular binding kinetics

Fig. 3

The Q factor of S11’s magnitude (A) is decreased for higher conductance samples since the real part of the impedance is increased. The minimum magnitude is shifted to a lower frequency due to the increase in conductance. The slope of S11's angle (B) is decreased when the conductance of the sample increases, increasing the real part of the impedance. The location where the S11 angle passes zero is shifted since the conductance increases. The sudden jump from −180° to 180° for the deionized water is due to the phase being wrapped. The phase passes through ±180° since the real impedance is less than the characteristic impedance of the VNA.

Back to article page