Lab 2 Report

What is the impedance of a quarter-wave shorted stub (a quarter wavelength of transmission line shorted at the load end)? Does this répresent a series or parallel resonant circuit?

Figure 1 shows a signal obtained after amplitude modulation by a sinusoidal message. The carrier frequency is difficult to determine from the figure, and is not needed for answering the questions (a)-(c) below. (a) Find the modulation index. (b) Find the signal power. (c) Find the bandwidth of the AM signal. (d) Determine the carrier frequency from the figure 20 10 0 -10 -20 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 Time (milliseconds)

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

Problem 5. We are transmitting our 12/4 APSK waveform with outer ring voltage 5 Volts and inner ring voltage = 2 Volts. The constellation ring ratio in dB is? a) 6.25 b) 7.959 c) 9.875 d) 9.945 e) 19.891

PLEASE SHOW ALL WORK 2. Following plot is the radiation pattern of an antenna. Determine: a)    Antenna gain in dBi and dBd b)    Front to back ratio in dB. (Show calculation steps by marking on the diagram)

4. What is the dominant TE mode and its resonant frequency in a hollow conduction cylindrical resonator with a radius of a and a length d? Explain it.

What is the effective noise temperature at the input of LNB when a TVRO parabolic dish reflector mixer stage has a noise figure of 20 dB and is preceded by an LNB with a power gain of 10 dB and an equivalent noise temperature of 60 K?

What is a stability margin in a bode plot?

A 10Vp carrier signal is amplitude modulated by two different frequencies 5 KHz and 10 KHz with amplitude of 4Vp and 7.5Vp respectively using an DSBFC. If the system is connected to the 100Ω antenna, (a) what is the modulated carrier power and AM wave total power? From DSBFC, different transmitters with different modulation schemes were used to evaluate the performance in terms of power and bandwidth and compare to conventional AM.

How to draw bode plot?

A signal is transmitted at 1 W from an antenna. Due to channel attenuation, the received signal power is 1 mW. Calculate the change in signal power in terms of decibels. (The answer should be one sentence saying "X" dB amount of decrease is observed.)