A certain low-loss non-magnetic dielectric material has a relative permittivity (εr ) of 2.5 and a loss tangent of 0.004. What is the phase constant (β) of a plane wave of frequency 11.3 GHz? (374.4)
A) β=2π×10⁹ rad/s
B) β=4π×10⁹ rad/s
C) β=6π×10⁹ rad/s
D) β=8π×10⁹ rad/s