A Bandpass Filter Based on Half Mode Substrate Integrated Waveguide-to-Defected Ground Structure Cells

Table 1

Comparison with filters presented in references.

Reference filter	Order	Topology	FBW^* and (GHz)	Insertion loss (dB)	Return loss (dB)	Size	2nd harmonic suppression (dBc)
[10]-1	3	HMSIW-slot	22% and 7.80	1.50	>10	0.52	>20
[10]-2	5	HMSIW-slot	40% and 8.79	1.20	>10	0.37	>28
[16]	3	SIW-CSRR	23% and 8.15	2.16	11.6	0.64
[23]	3	SIW-CSRR-DGS (bottom)	30% and 9.40	1.00	16	1.02	>20
This work	3	HMSIW-DGS	29% and 8.80	0.91–1.14	30	0.40	>35

FBW and stand for the fractional bandwidth and central frequency of the filters, respectively.
is the guided wavelength of the central frequency of the passband.