In a telecommunication trans-receive system, the transmitting antenna with antenna aperture of 1m is fed with 1W of power at 10GHz. The receive antenna with antenna aperture of 0.5m located at 1km away receives x mW of power. If the transmitting frequency changes to 20GHz, what will happen to receive power?

A

Increase by 3dB

B

Increase by 6dB

C

Decrease by 3dB

D

Decrease by 6dB