Theoretical and Experimental Comparison Results of Dual-Channel 3D Quasi-Optical Network System between Frequency Selective Surface and Wire Grid Polarizer

Table 2

The near-field measurement data of 324 GHz channel.

Filter	Cross-polarization level		Beam radius (ω) at D6 = 160 mm			Measurement consistency
	Simulation	Measurement	Simulation	Measurement	Theoretical value	ηs	ηv
FSS	−29.47 dB	−13.45 dB	15.710 mm = 16.966λ	14.44 mm = 15.595λ	15.145 mm = 16.35λ	96.5117%	92.3030%
Polarizer	−32.06 dB	−19.93 dB	15.375 mm = 16.605λ	14.74 mm = 15.919λ		99.9649%	98.6356%
Air	−31.91 dB	−18.44 dB	15.450 mm = 16.686λ	14.89 mm = 16.131λ		100%	100%