A transmission line has the following per-unit-length parameters: L = 0.5 H/m, C = 200 pF/m, R = 4.0 /m, and G = 0.02 S/m. Calculate the propagation constant and characteristic impedance of this line at 800 MHz. If the line is 30 cm long, what is the attenuation in dB? Recalculate these quantities in the absence of loss (R = G = 0).