Table 2.

A comparison study between the proposed MTM sensor and others was reported in the literature.

References	Material sensing	Operating frequency (GHz)	Dielectric constant (DK) value	Shift of $f_r$ (MHz)	Amplitude change of $S_{11}$ (dB)	Q-factor	FOM
20	Transformer oil	2–6	2.7 for clean and 2.9 for waste transformer oil	40	− 1.5	60	34
23	Oil	1–8	2.74 for clean oil and 2.87 for waste oil	63	− 0.9	90	32
27	Diesel	8–12	2.72 for branded diesel and 2.48 for unbranded diesel	60	− 2.5	110	37
28	Diesel	8–12	2.73 for branded and 2.47 for unbranded diesel	120	− 3.2	105	41
36	Transformer oil	8–12	2.8 for clean and 2.7 for waste transformer oil	70	− 4.5	100	48
	Oil	8–12	2.78 for olive oil and 2.6 for corn oil	50	− 0.8
37	Diesel	10–12	2.07 for branded and 2.68 for unbranded diesel	72	− 4	90	52
	Gasoline	10–11	2.43 for branded and 2.52 for unbranded gasoline	12	− 6
38	Diesel	8–12	2.08 for pure and 2.7 for adulterated diesel	100	− 10	95	38
44	Gasoline	8–12	2.43 for branded and 2.51 for unbranded gasoline	28	− 8	105	43
	Diesel	8–12	2.07 for branded and 2.68 for unbranded diesel	92	− 20
47	Transformer oil	8–12	2.9 for clean and 2.7 for waste transformer oil	70	− 3.7	75	36
	Lubricant	8–12	2.5 for clean and 2.3 for waste lubricant	60	− 4.1
Proposed work	Olive and corn oils	8–12	2.56 for olive oil and 3.07 for corn oil	100	− 10.74	135	76
	Sunflower oil and palm oil	8–12	2.93 for sunflower oil and 2.81 for palm oil	80	− 5.99
	Clean and waste brake oil	8–12	2.78 for clean and 2.69 for wase brake oil	70	− 3.97
	Benzene and carbon-tetrachloride	8–12	2.55 for benzene and 2.51 for carbon-tetrachloride	90	− 3.62