Fabrication of a 77 GHz Rotman Lens on a High Resistivity Silicon Wafer Using Lift-Off Process

Table 2

Comparison of key features.

Parameter	Reference [13]	Reference [14]	This paper
Frequency (GHz)	24	60	77
Material	RO3003 (𝜀𝑟=3)	Silicon and SiO2 (𝜀𝑟=11.7 and 3.9)	𝜀𝑟=11.8
Thickness (𝜇m)	508	300 and 1.5	200
Length × Width (mm)	7580	19.6×20	19.7×15.6
No. of beamports	5	5	3
No. of array ports	7	7	5
Phase error (deg.)	***	14.4	0.5
Insertion loss (dB)	1.85	2	3.29
Return loss (dB)	Almost 10	Almost 10	Almost 10
Max. Efficiency (%)	32.30	50	46.8