A transmitter has a power output of 10W at a carrier frequency of 250 MHz. It is connected by 10 m of a transmission line having a loss of 3 dB/100m to an antenna with a gain of 6 dBi. The receiving antenna is 20 km away and has a gain of 4 dBi. There is negligible loss in the receiver feedline, but the receiver is mismatched; the antenna and line are designed for a 50-2 impedance, but the receiver input is 75-2. assuming free-space propagation. А. Calculate the power delivered to the receiver, 204 nW В. 2040 nW С. 2.04 nW D. 20.4 nW

An X-band (λ = 3 cm) T/R module uses a power amplifier that exhibits a power addedefficiency on transmit of nominally 33% over a peak output power range from 0.1 W to 10 Wat 20% transmit duty cycle. In the transmit mode the module also requires 250 mW of DCpower to power the background control electronics. In the receive mode the module requires500 mW of DC power, including background control electronics. A radar is required to havea power-aperture-gain product of 80 dBWm2. Assume nominally 4,000 elements per squaremeter as an element density to satisfy scan volume requirements. Tabulate and plot the DCprime power required by the array for peak module powers from 0.1 W to 10 W and examinethe results.

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

4. Again, from the zigzag-path waveguiding model, explain why the group velocity is always slower than the phase velocity in a waveguide with a cutoff frequency.