Table 1.

Performance compared to other polarization insensitive structures.

Ref	Substrate material	Symmetricity	-10 dB RCS reduction bandwidth	Thickness (mm)	Incidence angle insensitivity	Polarization angle insensitivity
36	FR4	Twofold symmetry	Not tested	3 mm	≤ 300	Polarization selective
39	F4B & curing film	Fourfold symmetry	Not checked	4.16 mm	Not shown	0 ≤ 900
40	F4B-2 woven glass	Four fold symmetry	80.7% (17–42 GHz)	1.5	0 ≤ 400	Not tested
41	Ordinary glass	Four fold symmetry	62% (18–34 GHz)	1.1	≤ 450	Not tested
46	FR4	Four fold symmetry	52%(7–12 GHz)	3	0 ≤ 300	Not tested
47	F4B	Four fold symmetry	76.9(8–18 GHz)	3	0 ≤ 300	Only tested for x and y polarization
48	RTduroid 5880	Four fold symmetry	129% (11.3–51.7 GHz)RCS -7 dB	1.6	0 ≤ 400	≤ 900
Proposed	FR4	Two fold symmetry	91% (5.7–15.3 GHz)	3.2 mm	≤ 450	≤ 900