Table 3.

Comparison with the already designed sensors.

Ref.	Size (${\mathit{\lambda }}_{\mathit{g}}$)	${\mathit{f}}_0$ (GHz)	Technology	$\mathsf{\Delta }$F (MHz)	Sensing	Sensitivity (MHz/${\mathit{ϵ}}_{\mathit{r}}$)
[8]	0.5 × 0.5	4.4	SIW	500	Single	9.35–101 KHz/RH
[12]	NA	4–5	SIW	112.1, 265.7	Dual	17.5, 25.7
[15]	1.25 × 1.25	5	SIW	380	Single	69.07
[16]	0.21 × 0.21	2.02, 3.34	Microstrip	281, 309	Dual	3.57, 3.9
[17]	NA	4.7	SIW	70	Single	12.73
[18]	0.43 × 0.93	5.85	SIW	38	Single	5.84
[19]	1.7 × 1.98	17	SIW	145	Single	26.36
Type 1 Sensor	0.52 × 0.52	5.25	DRA	202	Single	8.75
Type 2 Sensor	0.52 × 0.52	5.25	DRA	450	Single	10.28