A transmitter has a directional antenna with a gain of 4 dB. The frequency is 72 MHz. The power into the antenna is 2 W. The receiver uses a one-quarter wavelength ground plane. The distance between the transmitting and receiving antennas is 3 mi. What is the power at the receiver? What is the receiver input voltage with a 50-V input impedance?

Problem 3. A receiver front end has a noise figure of 10 dB and a gain of 60 dB and a bandwidth of 12 MHz. The input signal power is 10-11 W. The antenna temperature is 180° K. Find Te, Ts, Nout, SNRin and SNRout. You may use To=290° K and Boltzmann's constant equals 1.38 x 10-23 J/K.

Question 3 Figure below shows how a single wire can be used to carry measurement data at the same time. This is done by modulating two widely different carrier frequencies with data and using filters to extract the data at the receiving end. Suppose one data channel is a modulated signal of 1.0 to 1.5 kHz and the other is a modulated signal of 50 to 55 kHz. Design the extraction filters using simple RC filters such that the data loss is restricted to 0.707 (3 dB, or 50% power) in the data signals. How much amplitude crossover results? (What is the amplitude ratio of the 50-55 kHz in the 1-1.5-kHz channel and vice versa?) Signal 1 50-kHz Modulator oscillator Filter1 Demodulator Signal 1 23-11 Adder Transmission 1-kHz Modulator Filter2 oscillator Demodulator Signal 2 Signal 2