Satellite Communication Numerical Problem 1

An Indian satellite transmitter work at a frequency of 4 GHz. Transmitter antenna has gain of 40 dBi and transmitter power of 7W. The receiver antenna has gain of 30 dBi and the path length is 40,000 km. compute the signal strength at the receiver side. A) -88 dBm B) -72.6 dBm C) -77 dBm D) -82.8 dBm