표 3. | Table 3. 2차 대역통과필터 스펙 비교 | Comparison of 2nd BPF specifications.

Ref.	Filter order	fC [GHz]	3-dB FBW [%]	I.L. [dB] (@ fC)	TZs	Structure size (λg×λg)	εr / tanδ	Etc.
[21]	2	2.4	-	1.3	-	0.0792(0.36×0.22)	4.2 / -	Single-layer PCB
[22]	2	2.36	5.93	4.8	2	0.0700(0.28×0.25)	3.38 / 0.0021	Single-layer PCB
[23]	2	2.6	16	1.7	4	0.0045(0.09×0.05)	41.5 / -	LTCC
[24]	5	8.3	108.43	1.2	6	0.3220(0.70×0.46)	3.38 / 0.0027	Multi-layer PCB
Parallel coupled line	2	3.56	13.76	1.7	-	0.0702(0.78×0.09)	4.3 / 0.02	Single-layer PCB
This work-Ⅰ (MFG Co. muRata)	2	3.56	9.83	2.1	2	0.0180 (0.09×0.20)	4.3 / 0.02	Single-layer PCB
This work-Ⅱ (MFG Co. SAMSUNG)	2	3.56	12.64	1.1	2	0.0200(0.10×0.20)	4.3 / 0.02	Single-layer PCB