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Electrical Engineering

Write down an expression for the voltage waveform, and sketch the waveforms of the harmonic components.

An a.c. voltage, V, comprises of a fundamental voltage of 100 V rms at a frequency of 120 Hz, a 3rd harmonic which is 20% of the fundamental, a 5th harmonic which is 10% of the fundamental and at a phase angle of 1.2 radians lagging. (i) Write down an expression for the voltage waveform. (ii) Sketch the waveforms of the harm

Range of local oscillator frequencies, Image frequency, Receiver's sensitivity, Sensitivity and dynamic range, System output

1. A receiver tunes the HF band (3 to 30 MHz), utilizes up-conversion with an intermediate frequency of 40.525 MHz, and uses high-side injection. Calculate the required range of local oscillator frequencies. 2. An AM broadcast receiver's pre-selector has a total effective Q of 90 to a received signal at 1180 kHz and uses an I

Why is it necessary to include an implementation margin when estimating the BER expected in a real digital communications link?

A satellite communication link transmits a QPSK signal at a rate of 10 Msps. The transmitter and receiver have ideal RRC filters with roll-off factor r = 0.25. At the input to the QPSK demodulator in the receiver, the CNR is 18.5 dB under clear air conditions (no rain in the link). a. What is the bandwidth occupied by th

Root Raised Cosine (RRC) Filters, Inter Symbol Interference (ISI), Noise Bandwidth

A digital communication system transmits binary data using polar NRZ pulses of current over a baseband link with a bandwidth of 20 kHz. The transmitter and receiver have ideal "Root Raised Cosine" (RRC) filters with roll off factor = 0.5. a. What is the minimum bandwidth that the link must provide to avoid generating IS

Characteristics of a filter

A filter has the following characteristics: Attenuation = 3.0 dB from 0 Hz to 2 kHz. From 2 kHz to 20 kHz attenuation increases from 3 dB to 23 dB in a straight line when plotted on axes of power in decibels (vertical axis) against log frequency ( horizontal axis). a. Is this a low pass, high pass, band pass or band sto

An audio signal is sampled, digitized and recorded on magnetic tape as a PCM signal. This process is analysed

An audio signal has a frequency range from 50 Hz to 20 kHz. The signal is sampled, digitized and recorded on magnetic tape as a PCM signal. a. Assuming that ideal filters are available, what is the lowest frequency at which the signal can be sampled and subsequently recovered in its analog form without distortion using a lo

Analysis of the Frequency Spectrum of Random Rect Pulses

A signal consists of rectangular pulses of duration 0.1 ms that arrive at a receiver at random intervals of time. What is the shape of the spectrum of the signal? What is the extent of the spectrum in the frequency domain? What is the unit that is applied to the magnitude of the spectrum?

A direct-to-home (QPSK) satellite television system uses a geostationary satellite in orbit above the equator. Some typical link parameters are determined including path loss over the link to Earth, the power received at the edge of the transmit beam, the noise power in the ground receiver, the CNR in clear sky conditions and the BER in rain conditions

A direct-to-home satellite television system uses a geostationary satellite in orbit above the equator at a longitude of 109 degrees west. The parameters of the satellite transmission are as follows: Transmit power 160 dBW Transmit antenna gain (edge of coverag

Op-amps: Slew rate, CMRR, RMS interference voltage, Closed-loop voltage gain, Input impedance, Critical frequency

1) When a pulse is applied to an op-amp, the output goes from -40 V to +5 V in 0.6 microseconds. What is the slew rate? 2) A certain diff-amp has a differential voltage gain of 1500 and a common-mode gain of 0.5. Determine the CMRR and express it in dB. 3) A certain diff-amp has a differential voltage gain of 3000 and a CMRR o

Linear Signal, Time-Invariant, Causal, and/or Memory-Less

Please walk me through the solutions for these problems, showing all work so that I can understand how these are done (see the attached file). 1) Determine if the signal given is linear, time-invariant, causal, and/or memory-less. y[n+1] + y[n] = 2x[n+1] - x[n] 2) For the series RLC circuit in the figure (in the att

Passband, Stopband and All-pass Filters

Please help with the following problems. 1. What are the distinguishing features of the response in the pass-band? 2. What are the distinguishing features of the response in the stop-band? 3. What is an all pass filter? 4. What does the frequency response of a filter measure or indicate?

Operational Amplifier Problems

1. Explain why an instrumentation amplifier has more than one stage? 2. How would you increase the output current of an op-amp? 3. Describe two ways to fix the output voltage offset of op-amps?

A. A digital radio link operates at a frequency of 75 MHz and uses ideal RRC filters with roll off factor r = 0.2 in the transmitter and receiver. The modulation used on the link is BPSK and the bit rate is 100 kbps. The 75 MHz transmitter has an output power of 1.0 W. Calculate the bandwidth occupi

Baseband Digital Transmission

A baseband digital data link transmits polar binary NRZ current pulses at a rate of 1.0 Msps. The link uses ideal RRC filters with roll off factor r = 0.5. a. Calculate the bandwidth occupied by the baseband binary signal. b. If the available channel bandwidth is 0.5 MHz, which of these can be used to transmit the di

Decompsotion of Time Domain Signals into Frequency Component

Please provide necessary explanations leading to the answer. a. A square wave signal with voltage levels 0 volts and 2.0 volt at a frequency of 1.00 MHz is multiplied by a sine wave at a frequency of 5.0 MHz. Which of the following frequencies are present at the output of the multiplier - there may also

Signal to noise ratio, Resonant frequency, Percent modulation, Transmitted power, Harmonic distortion

1. A microwave system requires a +4-dBm audio level to provide 100% modulation. Determine the voltage level required if this is a 600 ohm audio system. 2. Determine the noise produced by a 500 ohm resistor at 26 degrees Celcius over a 2 MHz bandwidth. 3. Consider an amplifier with an output of 2 mV rms and noise 0.76 mV rms.

Analysis of BPSK signals, BER with AWGN

A radio link sends BPSK signals to a receiver with a bit rate of 100 kbps. It is found that the output of a radio receiver when no signal is present is AWGN with a rms voltage of 1.0 V. a. What is the usual source of additive white Gaussian noise (AWGN) in a radio receiver? b. For what percentage of the time is the noi

Examination of a satellite QPSK link

A satellite communication link transmits a QPSK signal at a rate of 64 ksps. The transmitter and receiver have ideal RRC filters with alpha = 0.2. At the input to the QPSK demodulator in the receiver, the CNR is 19.0 dB under normal conditions (no rain in the link, known as clear air conditions). Assume an implementation mar

An underground twisted pair line is one mile long. The line is used to send a 1.50 Mbps signal as a polar binary NRZ voltage waveform. A logical 1 is transmitted as a +1.0 V pulse and a logical 0 is transmitted as a -1.0 V pulse. At the output of the receiver's sampling gate the pulses have peak amplitudes of +100 mV and -10

Op-Amps: cutoff frequency, input voltage, characteristics of the 741C

1. If the unity gain frequency is 5 MHz and the midband open-loop voltage gain is 200,000, what is the cutoff frequency? 2. An op amp has a voltage gain of 500,000. If the output voltage is 1V, what is the input voltage? 3. Name a few ICs other than op amps. 4. Above the cutoff frequency, what happens to the voltage gai

Baseband link equipped with an equalizer: maximum pulse rate, bit rate, average power and voltage

A baseband link is equipped with an equalizer such that its operating bandwidth is 1.00 MHz. Over this bandwidth the attenuation is constant at 25 dB and the phase shift is linear with frequency. The link is used for the transmission of digital signals. The transmitter and receiver have ideal RRC filters with roll off factor

A digital radio link is designed to carry a T1 rate digital signal (1.544 Mbps). The transmitter and receiver have ideal RRC bandpass filters with roll off factor (r) = 0.2. a. What RF bandwidth must the radio link provide if the modulation is binary phase shift keying (BPSK)? b. The link is unchanged but the modu

Twisted Pair Telephone Line: maximum symbol rate, bit rate

A twisted pair telephone line is equipped with an equalizer that ensures the line has a constant attenuation between 300 Hz and 3300 Hz, and linear phase shift with frequency. A carrier at a frequency of 1800 Hz is modulated with QAM so that digital data can be transmitted on the twisted pair. The transmitter and receiver have

Sampling and gausssian distribution

Assume, I have a Gaussian Distribution given by N~(u0,var) where u0 is mean and var is variance by sampling 999 points. I used Maximum Likelihood to get the above parameters i.e. u0 and var. Now from these 999 points, I take one point out (lets call it i) and add a new point (lets call it j). What will the new mean and v

Output Signal

Would you be able to help me with this questions? A 2 second pulse is transmitted through a communication channel. The output of the channel x(t) , is given by x(t) = eâ?'0.5tu(t) â?' eâ?'0.5tu(t â?' 2) . (i) Sketch the output signal; and (ii) Derive the expression for X (s) .

Optimum length of the antenna to receive the FM station

An FM radio station transmits at a frequency of 99.9 MHz. A radio receiver has an antenna that is a quarter wavelength monopole consisting of a telescoping rod (as seen on most portable FM radio receivers). What is the optimum length of the antenna to receive the FM station, correct to the nearest cm?

Bandwidth: Typical telephone link, NTSC video signal

A. What is the bandwidth of a typical telephone link? Give two advantages and two disadvantages of using this bandwidth compared to a much wider bandwidth, such as the 50 Hz to 20,000 Hz of a CD recording. b. Why can't a video signal such as an NTSC analog television signal be transmitted over a two km length of loaded twiste

PCM and PAM transmissions, Main difference between the amplifiers used in analog and digital systems

A. What do the letters PCM and PAM stand for? Why is PCM transmission preferred over PAM transmission? Give at least two reasons in your answer. b. A four wire analog transmission circuit requires amplifiers at specific intervals if the distance between terminals exceeds 10 miles. A PCM transmission system also requires a

Audio signal, Sampling frequency, Bit rate at the output of the ADC, Maximum bandwidth, Quantization SNR

An audio signal has a bandwidth that extends from 100 Hz to 10 kHz. The signal is sampled to create a PAM signal and then digitized by an analog to digital converter (ADC) that has 8 bits. The digital signal is transmitted as a bit stream to a distant location where it is converted to parallel words and input to a digital to a

Analyzing a Square wave in terms of sin components

A. A signal generator outputs a unipolar square wave with a period of 0.50 ms. The output of the generator is passed through an ideal low pass filter that has a cut off frequency of 4.5 kHz, to a spectrum analyzer. What frequencies would be seen on the spectrum analyzer screen? b. The signal generator output in part (a)