Consider the following inverter circuit: For the CMOS inverter shown, let VDD = 3.3 V, kn = 80 μA/V2, kp′ = 50 μA/V2, VTN = 0.4 V, and VTP = −0.4 V. (a) Let (W/L)n = 2 and (W/L)p = 5. Find Vo for VI = 0.7 V and VI = 2.8 V Find VI for Vo = 0.25 V and Vo = 3.05 V Find the transition points for the p-channel and n-channel transistors. Sketch the voltage transfer characteristics indicating the points calculated before (b) Repeat part (a) for (W/L)n = 4 and (W/L)p = 5.
Q5) In the following MOSFET transistor, a) State the operation region of the transistor (proof whether it is in cutt-off saturation or triod region) b) Design the following circuit to estabilish a drain voltage 0.10 V. Find the value of RD. Find the effective resistance of drain and source at this operating point. Let the MOSFET transistor have Vt = 1 V, kn′(W/L) = μnCox = 1.2 mA/V2. Neglect the channel length modulation effect (assume λ = 0)
Consider the periodic modulating signal shown below. For a carrier frequency of ωc = 8π [rad/s], find: (a) Sketch the full AM signal for a modulation index of 0.5, and ∞. (b) If the signals in (a) are passed through a peak detector, sketch the signals at the output of the detector. (c) Determine the power efficiency in each case of part (a). (d) Determine the bandwidth of the AM signal.
Signal m(t) (shown above) is used to modulate a carrier Acos(2πfct) (where fc ≫ 1000 Hz) using the following 3 modulation schemes: a-DSB-SC b-DSB with Carrier (modulation index μ = 0.5) c-DSB with Carrier (modulation index μ = 2) i. Write an expression of the modulated carrier and plot it versus time for each case ii. Calculate the power efficiency for each case (hint: cos2θ = 0.5(1+cos2 θ) ) iii. If the modulated carrier is applied to an envelope detector, plot the output signal versus time for each case. Comment about the suitability of the envelope detector for each case
If the modulated wave for AM is S(t)AM = Ac(1 + Kam(t))cos(2πfct). Where m(t) is the information signal and Accos(2πfct) is the carrier signal. The AM wave is plotted in frequency domain as in figure1- Determine Ac, Am, fc, fm 2- The bandwidth of the wave. 3 -sensitivity of the modulator. 4- Determine the average power at the carrier (assume the 1 ohm resistor). Noto : assume Modulation index 1. Fig. 1. AM wave in Frequency domain
(a) Draw 150% and 200% DSB+C AM modulated signal with proper labeling. Calculate the efficiency for a DSB +C AM signal which has both the modulation indices as stated above. [4+2] (b) In the figure below, x(t) = sinωct is the given signal and ωc = 20 k. It is sampled with a train of pulse signal s(t)¯, where T = 20 μs. The sampled version of the signal is y(t). Sketch the spectrum of X(ω), S(ω) and Y(ω). [6] (c) How can you reconstruct x(t) from y(t) ? Draw with proper block diagram and labeling. [3]
A baseband message signal with an amplitude of +/−3 volts and a single-sided bandwidth of 4 kHz has been modulated using a Frequency Modulation (FM) scheme. Assume the frequency modulator has a carrier frequency of 80 kHz and a frequency sensitivity of: Kω = 3400π (rad/sec)/volt. Use Carson's rule to determine the bandwidth of the modulated signal. B = 18.2 kHz B = 4 kHz B = 9.1 kHz B = 84 kHz B = 8 kHz B = 80 kHz
(b) Consider an Amplitude Modulation (AM) system as shown in Figure 3(a). The input or message signal to this system is x(t) = cos(10πt). The carrier signal is c(t) = cos(1000πt). Answer the following questions for this system: i. Plot z1(t) = x(t)c(t) as a function of time. ii. Plot the spectrum of |Z1(ω)|, |Z2(ω)| and |Y(ω)| vs. ω Figure Q3b
An amplitude modulated wave is given by s(t) = [1 + kam(t)]c(t), where ka is the modulator sensitivity, m(t) is the message wave and c(t) is the carrier wave. Assume that a sinusoidal signal is chosen as the carrier wave; c(t) = cos(2πfct), where fc is the carrier frequency. Let the message signal m(t) be a periodic triangular pulse wave shown in Fig. 1 Figure 1: Message signal m(t) (a). Find ka for 50% modulation. [hint: Percentage modulation is defined as max|kam(t)| × 100% ] (b). Sketch the amplitude modulated signal s(t) for 50% modulation.
Sketch the AM signal φAM(t) = Acosωct + m(t)cosωct for the periodic signal m(t) shown in Figure 1 corresponding to the following modulation indices. (a) μ = 0.25; (b) μ = 1; (c) μ = 1.25; and (d) μ = ∞.
Sine-triangle modulation or SPWM is commonly used to regulate the DC to single-phase AC conversion. A bipolar PWM is demonstrated in the following figure. Based on the waveform, determine the frequency modulation ratio.
An input binary sequence 1 0 1 1 0 0, is modulated for transmission with the following digital modulation techniques. where, input sequence bit rate Rb = 33.333 Kbps and carrier frequency (fc) = 10 MHz. a) B PSK b) 8 Ary PSK c) B FSK d) 4 Ary-ASK (fc2 = 2 fc1) for each case of the above modulation techniques i. Sketch the time domain waveforms of the given input bits stream and the passband modulated signal for the above four cases. ii. Write down an expression the passband signal for each case. iii. Plot the signal space for each case of the following modulation techniques
1)The baseband with a bandwidth of W is preceded by an x(t) sign in the form of s(t). Ts sec at Nyquist frequency with pulse sequence. are sampled at intervals and the sampled sign xs(t) is applied to the circuit with the impulse response h(t) (Fig. 1). As can be seen, this system is a pulse amplitude modulation (PAM) system in which triangular pulses are used instead of rectangular pulses. Figure 1-PAM Modulator a) Find and plot the Fourier transform of s(t). b) Since the sample values are in the form of show that c) Find and draw the sampled sign xs(t) and Xs(f). d) Find the XPAM (t) mark and |XPAM (f)| on the modulator output and draw them roughly. e) Design the demodulator circuit with all its parameters so that x(t) can be obtained in the receiver part.
Bandlimited Baseband Modulation (18 points) Consider an M-ary PAM baseband communication system. The communication channel is an ideal lowpass filter with a cutoff frequency (or bandwidth) of W = 8 kHz. Let us denote the signal component at the output of the receiving filter as x(t) and its Fourier transform as X(f). Suppose the system is designed such that X(f) is a raised cosine spectrum: X(f) = {T0 ≤ |f| ≤ 1−α2 TT2[1+cos(πTα(|f|−1−α2 T))]1−α2 T ≤ |f| ≤ 1+α2 T0|f| > 1+α2 T where 0 ≤ α ≤ 1, and the corresponding x(t) is x(t) = sinc(tT)cos(παt/T)1−4 α2 t2 /T2 Note: sinc(x) = sin(πx) πx (a) Suppose there is no inter-symbol interference (ISI), then what is the maximum symbol rate supported by the channel, and what is the symbol rate when a "true" (α = 1) raised cosine spectrum is used? (b) Determine and plot the shape of x(t) when the maximum symbol rate is used, identify the zero crossings, and explain why there is no ISI.
Recall that for binary antipodal modulation, the bit error probability is given as Pb = Q(2Eb N0) whereas for binary orthogonal modulation it is Pb = Q(Eb N0). Assume the signals s1(t) and s2(t) above are used for binary antipodal modulation and s3(t) and s4(t) are used for binary orthogonal modulation. Let the value of A be 1 Volt for all signals and let N0 be 10−6 Watts/Hz. We would like to have a bit error probability of Pb = 10−6. (a) Calculate the value of T1 for Pb = 10−6. (b) What is the corresponding transmission rate in bits/second? (c) Calculate the value of T2 for Pb = 10−6. (d) What is the corresponding transmission rate in bits/second? (e) Does the ratio of T1 /T2 change with respect to what P6 is? Hint: Q(4.7535) = 10−6
Conventional AM The message signal m(t), which is given in Problem CP-3.1, modulates the carrier c(t) = cos2πfct using conventional AM. The carrier frequency is fc = 250 Hz and the modulation index is a = 0.80. Plot the message signal m(t) and the modulated signal u(t) using a sampling interval ts = 0.0001. Determine and plot the spectra of the message signal m(t) and the modulated signal u(t). Repeat Parts 1 and 2 when t0 = 0.4, and comment on the results between t0 = 0.1 and t0 = 0.4.
A 1.0 kHz tone is used to generate both an AM and an FM signal. Unmodulated carrier amplitude is the same for both AM and FM. The modulation index β of FM is 12 . If the frequency components at (fc ± 1000)Hz have the same magnitude in AM as well as FM, then the modulation index of AM is a. 48.00 b. 12.00 c. 24.00
A polar NRZ baseband signal is modulated using a 16−PSK modulation scheme. This modulated signal is observed to have a transmission bandwidth of W = 350 MHz. If this same signal was instead modulated using 4-PSK (QPSK) what would the transmission bandwidth be? W = 700 MHz W = 175 MHz W = 350 MHz W = 1.4 GHz W = 1.6 GHz W = 2.8 GHz
Question 4. [20 points] Consider the Double Sideband-Large Carrier (DSB-LC) modulated signal s(t) : s(t) = 10cos(304×103πt) + Acos(300×103πt) + 10cos(296×103πt) a) Determine the message signal m(t) and the carrier signal c(t). b) Calculate the carrier power and the power in the sidebands. c) Find A for the modulation index, μ = 0.8. d) Find A for a power efficiency of 10%.
a) Figure Q1(a) shows a sinusoidal modulated DSBFC (or DSBLC) waveform with modulating signal period, Tm of 1 msec and carrier signal period, TC of 0.125 msec, respectively. Figure Q1 (a): Full AM Waveform i. Determine the modulation index, m ii. Determine the modulating frequency, fm and the carrier frequency, fc iii. Sketch a line spectrum iv. Calculate the ratio of the average power in the sidebands to that of the carrier v. Determine the amplitude of the additional carrier which must be added to attain a modulation index of 10%
a) Define the modulation index (m) in Amplitude Modulation (AM). (2 marks) b) Sketch the Double Side Band Full Carrier (DSBFC) signal for a single tone modulation with modulation index of i) m = 0.5 (2 marks) ii) m = 1 (2 marks) c) Define the transmission efficiency ( η ) of DSBFC (2 marks) i) Calculate the efficiency (η) of the A. M signal when m = 0.5 ( 50 percent modulation). (4 marks) ii) Show by calculation that for a single tone AM, maximum efficiency (ηmax) is 33.3% when m = 1. ( 5 marks) d) Prove that a synchronous demodulator as shown in Figure Q2 can demodulate an AM signal regardless of the value of A (8 marks) xAM(t) = [A+m(t)]cosωct m(t) is the information, A amplitude of the carrier xAM(t) Figure Q2 AM Demodulator
An amplitude modulation system in Figure 2. A has an input signal x(t) and carrier signal m(t) = cosω0t. The spectrum for signal x(t) is shown in Figure 2. B. a) By using Fourier transformation properties, i. determine the equation G(ω) and ii. sketch the spectrum G(ω). Figure 2. A Figure 2. B b) If the modulated signal G(ω) is being transmitted, suggest a modulation system with filtering in the receiver to get back the input signal form, denoted as X^(ω). Explain your system with the aid of diagrams, output spectrums and the frequency domain formulation.
For an FM modulator with modulation index m = 2, modulating signal vm(t) = Vmsin(2π2000t), and an unmodulated carrier vc(t) = 8 sin(2π800 kt), a. Determine the number of sets of significant sidebands b. Determine their amplitudes c. Draw the frequency spectrum showing the relative amplitudes of the side frequencies d. Determine the bandwidth e. Determine the bandwidth if the amplitude of the modulating signal increases by a factor of 2.5
Consider a DSB-SC modulated wave using message signal m(t) with spectrum shown in the following figure and a carrier signal c(t) = Accos2πfct. The DSB-SC modulated wave is applied to a coherent detector using a locally generated sinusoid cos(2πfct). The coherent detector consists of a product modulator and a low-pass filter (with a bandwidth of fm). (a) What is the spectrum of the product modulator output, denoted by V(f)? (b) Sketch the spectrum of the detector output when fc = 1.25fm and fc = 0.75fm. (c) What is the value range of fc for which the coherent detector can demodulate the message signal m(t)?
An amplitude modulated (AM) signal, xAM(t), is represented by the following expression: xAM(t) = [Ac + m(t)]cos(2πfct + π). The carrier frequency, fc = 107 Hz and the power in the modulation signal, m(t), is represented as Pm. (i) Derive an expression for the power efficiency, η, of the AM signal, xAM(t), in terms of Pm. (ii) Given that the modulation index, μ = 0.5, determine the power efficiency, η, of the modulating signal m(t) shown in Figure B1 c overleaf. Figure B1 c: Triangular waveform as modulating signal, m(t).
Amplitude Modulation Throughout this problem, assume that the message signal m(t) is given as m(t) = cos(2πfmt+ϕ). The frequency of the second set of mixers is f2 = fc+fm, where the carrier frequency fc is much higher than fm. Let m(t) be input to the system in Figure 1. The cutoff frequency of the lowpass filters equals fm. Figure 1: System for AM Problem (a) Find the Fourier transform M(f) of the message signal m(t). (b) Compute the signals u1(t) and u2(t) as well as their Fourier transforms U1(f) and U2(f). (c) Compute the ouputs of the lowpass filters, v1(t) and v2(t), as well as their Fourier transforms V1(f) and V2(f). (d) Find the output signal sp(t) and its Fourier transform Sp(f) (e) How would you describe what this system does?
In an amplitude modulation system, the message signal is given below and the carrier frequency is 1 kHz. The modulator output is y(t) = [2b + 0.5m(t)]cosωct. (a) Determine the average power in y(t) as a function of b. (b) If b = 1, determine the modulation index and the modulation power efficiency. (c) Find the minimum value of b such that the AM signal can still be demodulated via envelope detection. (d) Determine maximum modulation index and maximum modulation power efficiency based on the resulting b.
Given an FM modulated signal as XFM(t) = 100 cos[2π(1000)t + ∅(t)] If the message signal entering the FM modulator is given by: m(t) = 5 cos[2π(8)t], and the deviation constant fd = 8, Determine: a- The modulation index. b- The phase deviation ∅(t) c- The bandwidth according to Carson's rule. d- If a BPF filter is to be used at the output of the FM modulator with a transfer function H(f) as shown below, determine the power at the filter input and output terminals.
Question 2 (DSB-SC Amplitude Modulation): Design a DSB-SC AM modulator to generate a modulated signal ks(t)cos(ωct + θ), where s(t) is a signal band limited to B Hz. The following figure demonstrate a DSC-SC amplitude modulator which is available in the stockroom. The available carrier generator can only generate cos3(ωct) (Note: it cannot generate the standard cos(ωct)). Explain whether you would be able to generate the design using only this available equipment. You may use any kind of filter you like. (Note: ωc = 2πfc) (a) (b) Figure 1. The DSB-SC Amplitude Modulaion What kind of filter is required in Figure (a)? Determine the signal spectrum at point b and c in Figure (a), and indicate the frequency bands occupied by these spectrums.
Consider an amplitude modulation with carrier (DSC-WC) having a modulation index of 0.5. The message signal m(t) is a periodic signal as shown in the figure. a) Sketch the modulator structure. If the carrier frequency is 5 kHz, sketch the modulated signal which is transmitted (in time domain). b) You may use envelope detector circuitry to recover the signal m(t). Draw this circuitry and explain its function.
Fourier Transform The modulation property of the Fourier transform. (a) Let f(t) be a signal, s0 a number, and define g(t) = f(t)cos(2πs0t). Show that Fg(s) = 1 2 Ff(s − s0) + 1 2 Ff(s + s0) (b) Find the signal (in the time domain) whose Fourier transform is pictured, below.
An Information signal m(t) = cos(500t) is Frequency modulated with the carrier frequency C (t) = 20cos(10000t). Write the complete Modulated waveform. Find instantaneous phase and instantaneous frequency at t = 0 and = 0.005. Find the frequency deviation and frequency sensitivity, Find the modulation index Find the Power of the carrier signal Find the Total Power of the signal What happen to the total power if the amplitude of the massage signal increased? If the information signal is as follows, find the transmitted spectrum. Sketch it.
The modulating (or message) signal into an FM modulator is m(t) = 12cos(30πt) where the frequency deviation constant of the modulator is kf = 20π. The frequency and amplitude of the carrier is 2000 Hz and 10 V, respectively. a) Determine the expression for the signal at the output of the FM modulator in the time domain along with its bandwidth. b) Determine maximum frequency deviation in Hertz. c) Determine the peak phase deviation in radians. d) If the channel noise is white noise with a power spectral density of η/2 = 10−7 W/Hz, calculate the SNR at the output of the demodulator. State your result in dB. e) The FM modulator is followed by an ideal bandpass filter having a center frequency of 2000 Hz and a bandwidth of 92 Hz. The gain of the filter is 1 in the passband. Determine the power of the modulated signal at the output of the filter.
Suppose that we modulate the periodic message signal m(t) given in the figure by PM modulation with kp = 1000π. Assume that the bandwidth of the message signal is its fifth harmonic frequency. What is the bandwidth of the modulated signal? select one: 8 kHz 4 kHz 6 kHz
The following figure shows a switching modulator. Assume the lowpass message signal m(t) has bandwidth 3000 Hz and max|m(t)| = 0.2. The carrier signal is c(t) = cos(2π15000 t). x(t) = m(t)+c(t). After the diode, the signal y(t) is periodic and thus its Fourier series representation is y(t) = x(t)[12+2πcos(2π15000 t)−23πcos(2π3×15000 t)+25πcos(2π5×15000 t)−⋯]. (1) With an appropriate bandpass filter BPF, this modulator can conduct AM modulation. Please determine the magnitude spectrum of the ideal BPF (e. g. , determine its center frequency and bandwidth). Find the output AM signal waveform expression s(t) and its percentage modulation. (2) Can it work as a DSB-SC modulator? If yes, please also find the appropriate magnitude spectrum of the ideal BPF and find the output DSB-SC signal waveform expression s(t).
To generate an angle-modulated signal, u(t), a message signal, m(t), is used to frequency modulate a carrier signal, c(t), where m(t) = 5cos(20000πt) and c(t) = 100cos(2πfct). If the peak-frequency deviation is 20 kHz and fc = 100 MHz, determine: (i) an expression for the frequency modulated signal, u(t); (ii) the modulation index, β, and the approximate bandwidth of the generated FM signal using Carson's rule; (iii) the amplitude of all signal components that have power level of at least 10% of the power of the unmodulated carrier component; (iv) the frequency of the signal components in c)(iii).
A conventional amplitude modulated signal is given as, s(t) = [6 + 4cos(400πt)]cos(2800πt) Determine the SNR (in dB) of the output signal y(t) of the receiver given in Fig. Q5, if the PSD of noise is Sn(f) = 10−6
(a) A modulation signal 2 cos(2π103 t) V is used to amplitude modulate a carrier wave 10 cos(2π104 t) V. (i) Determine the carrier and modulating frequencies. (ii) Determine the transmission bandwidth. (iii) Determine the percentage modulation. (iv) Determine the carrier and sideband powers if the AM wave is dropped across a 50 Ω load. (b) Explain the operation of the Costas receiver, shown in Fig. 2, when used to demodulate a double-sideband suppressed carrier AM signal. In your answer show equations for the signals at A, B, C, D and E. Fig. 2. Costas receiver.
Figure 2 portrays the fundamentals of amplitude modulation (AM), in particular, double-sideband (DSB) AM. The message signal is g(t), and cos(ω0t) = cos(2πf0t) is the carrier. (a) (b) Fig. 2: Fundamental double-sideband (DBS) amplitude modulation (a) Mathematically derive the spectrum or Fourier Transform of g(t) directly from the formula/definition of Fourier Transform. (NOT using the tables of Fourier transform properties. ) (b) Express the spectrum or Fourier Transform of g(t)cos(2πfot) in a Mathematical manner. It is described in a graphical manner in Fig. 2-(d). (c) Describe how to demodulate this signal at the receiver. Draw the spectrum of the demodulated signal in the frequency domain.
Question 2: In an amplitude modulation system, the message signal is given as shown below: The carrier frequency is 1 kHz and the modulator output is: s(t) = 2[b + 0.5 m(t)]cos(2πfct) a) Determine the average message power. b) If b = 1, determine the modulation index and the modulation power efficiency. c) Sketch the modulated signal s(t) = 2[b + 0.5 m(t)]cos(2πfct) in time domain if b = 1. d) Draw the detailed receiver structure and show the signals at all the stages of the receiver. e) Discuss the system, if b = 0.5.
The message signal for a phase modulation (PM) is given in Figure 1. a as shown. The carrier signal has an amplitude of Ac = 1 Volt and a frequency of fc = 100 kHz, with a frequency deviation of Δf = [15] kHz. Since the resulting PM signal is demodulated as shown in Figure 1. b, please draw the signals formed at points c, d, e, and f. (The YGF in the figure only suppresses the DC component. Please indicate the amplitude and frequency information in the figures you draw. ) Figure 1. a Figure 1. b
Consider a phase modulated (PM) signal of the form xc(t) = Accos(2πfct + kpAmcos(2πfmt)). This modulated signal is applied to an ideal BPF whose characteristics are given below: Figure 1: The Bandpass Filter. (a) Find the Fourier series expansion of the signal xc(t). Note that xc(t) = Acℜ{ej(2πfct + kpAmcos(2πfmt)}, where ℜ{. } denotes real part of a complex number. (b) Determine the envelope, phase and instantaneous frequency of the modulated signal at the filter output as functions of time.
4.3-2 In an amplitude modulation system, the message signal is given by Fig. P4.3-1 and the carrier frequency is 1 kHz. The modulator output is sAM(t) = 2[b + 0.5 m(t)]cosωct (a) Determine the average power in sAM(t) as a function of b and A. (b) If b = A, determine the modulation index and the modulation power efficiency. (c) Find the minimum value of b such that the AM signal can still be demodulated via envelope detection. Determine maximum modulation index and maximum modulation power efficiency based on the resulting b.
b) In the analog modulation technique known as Frequency Modulation, the input carrier frequency to a frequency modulator is a 570 kHz signal with an amplitude of 30 V. At the output of this modulator, this signal has deviated for 9 kHz from its original value. Given the modulation index, mf of the system is 3. i. Calculate the value of modulating signal frequency. ii. Construct the general equation for the output signal of this frequency modulator circuit. iii. Using Bessel Table, indicate the number of sideband pairs produced. Figure 2.0: Basic Modulation system
Given two sinusoidal signals x1(t) and x2(t) such that: x1(t) = 5cos(500πt) x2(t) = 2sin(10000πt)Assuming an angle modulation scheme, which signal can be considered the carrier signal and which signal is considered the message signal? Write an expression for a PM signal, assuming a phase modulation index of 2/15. Write an expression for an FM signal, assuming a maximum frequency deviation of 75 KHz. For the FM signal, determine if it is a NBFM or WBFM, and draw a suitable modulator block diagram. For the FM signal, find the approximate bandwidth using Carson's rule. Assuming the amplitude of x1(t) is doubled, how will the FM signal be affected? Assuming the amplitude of x2(t) is doubled, how will the FM signal be affected?
Frequency Modulation (FM) is one of the earliest techniques for encoding data in magnetic storage devices, e. g. floppy disk drives. The figure below shows a waveform written to store an ASCII character on a hard disk using FM. Retrieve the binary number. T = Transition (magnetic flux reversal) N = No transition
The fundamental concept of single-sideband (SSB) amplitude modulation (AM) is described in Fig. 3. Referring to the figure, derive the time-domain representation of the lower-sideband (LSB) AM signal. The detailed derivation is mandatory. Lastly, explain how to demodulate the LSB AM signal; then, draw a plot of spectrum for the demodulated signal. (a) (b) (c) (d) (e) Fig. 3: Single-sideband (SSB) amplitude modulation (AM)
The process of impressing low-frequency information signals onto a high-frequency carrier signal is called modulation. Amplitude modulation (AM) is the process of changing the amplitude of a relatively high frequency carrier signal in proportion with the instantaneous value of the modulating signal. Consider an Amplitude Modulation (AM) wave signal v(t) = [15 + 4sin(44×103 t)]sin(46.5×106 t). i. Determine the type of the AM signal. [2 marks] ii. Calculate the powers of the carrier and side bands in dBm. [4 marks] iii. Draw the power spectrum with a clear label of the frequencies and amplitudes for all the components. [4 marks]
A combined modulator/demodulator is shown below: The input signal is x(t) = sinc2(t) + 2cos(18πt). The magnitude of frequency response of the ideal BPF is (a) How should the carrier frequency fc, the cutoff frequency of the Low Pass Filter fcutoff, and the gain of the Low Pass Filter, A, be selected such that y2(t) = x(t)? (b) For the selected value of fc, what type of modulation is this?
(a) An AM signal is given by φAM(t) = [20 + m(t)]cos(2πfct). Find the maximum value of the amplitude Am of the modulating signal m(t), as shown in the following figure, such that no distortion in the modulated signal would occur. Find also the corresponding modulation index. The figure for Problem 01 . (b) A baseband signal is given by m(t) = cos100t cos200t and the carrier signal is given by C(t) = 10cos5000t. Find and sketch the spectra of the DSB-SC modulated signal. Find also the upper sideband and the lower sideband. (c) What is the major drawback of SSB-SC and how can we overcome it?