Near-ground radio propagation In free space, the electric field received by a receiver antenna which is separated from a radiating transmitter antenna by a distance d is Eðd; tÞ ¼

E0d0 d

cos !c t 

d c




:

The received power is given by the Friis free-space equation PrðdÞ ¼

PtGtGrl2

ð4pÞ2d2

:

In the two-ray ground reflection model as depicted in Figure 3.15, the received electric field is ETOTðd; tÞ ¼

E0d0 d0 cos !c t 

d0 c






E0d0 d00 cos !c t 

d00 c




:

The T–R separation distance d is very large compared with hr and ht. Derive the received signal power.