Table 2.

Comparison of different microwave glucose sensors.

Ref	Sensing technique	Operating frequency (GHz)	Test solution	Sample volume (µL)	Concentration (mg/dL)	Sensing parameter	S (per MHz/[mg/dL])
60	Microstrip based series resonator	6.5	Aqueous solution	50	0–70,000	fR (S21)	3.13E−05
38	Spatially separated SRR	1.4	Aqueous solution	600	504–3531	fR (S21)	1.83E−04
55	Dielectric resonator	1.68	Aqueous solution	5	5000–30,000	fR (S11)	2.00E−04
61	Rectangular waveguide cavity	1.9	Aqueous solution	43–170	500–2500	fR (S21)	4.00E−04
62	Patch antenna	5.0	Saline-glucose solutions	36,000	0–250	fR (S11)	1.09E−03
63	Open split ring resonator	6.5	Aqueous solution	–	0–40,000	fR (S21)	1.88E−03
40	ENG unit-cell resonator	2.074	Aqueous solution	2	2000–10,000	fR (S21)	1.00E−02
64	Single-port resonator	4.8	Aqueous solution	125	100–1000	fR (S11)	1.40E−02
65	Distributed MEMS transmission lines (DMTL)	16	Aqueous solution	–	0–34,780	fR (S11)	1.64E−02
66	Interdigitated capacitor (IDC) resonator-etched coplanar waveguide (CPW)	2.46	Aqueous solution	2	0–8000	fR (S21)	2.00E−02
41	Complementary electric-LC (CELC) resonator	1.0–1.70	Aqueous solution	0.63	2000–10,000	fR (S21)	2.11E−02
67	Split ring resonator	4.18	Aqueous solution	–	0–5000	fR (S21)	2.60E−02
This work	Complementary split ring resonator driven by an ISM Radar	2.45	Aqueous solution	600	40–140	fR (S21)	4.5–9.50E−01 (dispersed) 6.3–12.5E−01 (compact)