Review of 3D Printed Millimeter-Wave and Terahertz Passive Devices

Table 1

Measured inner surface roughness of V-band horns.

Sample	Spv (μm)	Sq (μm)	Sa (μm)	IsoFlatness (μm)
(a)	129.00	16.10	12.89	127.42
(b)	142.84	6.73	4.64	128.27
(c)	67.74	9.46	7.82	59.56
(d)	30.10	3.52	2.79	25.49
(e)	20.50	1.67	1.29	19.89
(f)	39.35	0.54	0.25	37.67