2 a. Determine the scattering matrix of a lossless circulator (clockwise) that has insertion [5] loss of 1.5 dB and an isolation of 25 dB. b. Design a 5 dB Branch-line coupler for the system impedance of 50 Q and center [5] frequency of 5 GHz. Draw the top view microstrip layout of the coupler on substrate.

A signal with a power level of 4 mW is applied to the input of a directional coupler. The output from the main guide is measured at 2.2 dBm and the output from the secondary guide is measured at -18 dBm.   A.) Calculate the insertion loss for this device in dBs. B.) Calculate the coupling loss for this device in dBs.

6-1. You are designing an FDM-PCM/FDMA analog link that will occupy 36 MHz of an INTELSAT VI transponder with 10 users of equal bandwidth. The uplink and downlink center frequencies of the occupied band are 5985.5 MHz and 3760.5 MHz. The distance from the satellite to your earth station is 40,000 km. The saturation uplink flux density (total - all carriers) for your uplink is - 75 dBW/m2 and the satellite's G/T is = -11.6 dB/K. At saturation, the transponder EIRP for your downlink is 29 dBW and the earth station's G/T is 41 dB/K. Assume that the transponder is linear (an unrealistic scenario - but do it this way such that BOI = BOo, dB. The intermodulation carrier to noise ratio, (C/N), in dB, is related to the back-off BOo in dB by (C/N)31M = 7.86 - 0.714 * BO0 In other words, at Xponder saturation the value of (C/N)31M = 7.86 dB and for example BOo = -6 dB the (C/N)31M = 7.86 0.714*(-6) = 12.14 dB. (a) Find the maximum overall carrier-to-noise ratio (C/N), in dB that this link can…

Question 3 a) For a single-frequency sine wave modulating signal of 3 kHz with a carrier frequency of 36 MHz, what is the spacing between sidebands? b) A carrier of 49 MHz is frequency-modulated by a 1.5-kHz square wave. The modulation index is 0.25. Sketch the spectrum of the resulting signal. (Assume only harmonics less than the sixth are passed by the system.)

Problem 2 AConsider a cellular system of hexagonal structure. It is assumed that all the base stations transmit with the same power and the path loss follow the break-point model with exponent 4. The required S/I (signal power to interference power ratio) is 12dB. The fading margin is 10dB. What is the minimum cluster size?

Q6. Figure Q6 shows the line spectrum of a modulated signal (all components are positive and real). 3 1 232 234 236 238 frequency/kHz Figure Q6: Line spectrum of a modulated signal (a) Describe the modulation scheme. (b) What are the values of the carrier frequency, modulation frequency and the modulation index? (c) What is the transmission efficiency (ratio of modulated to total power) in this example? (d) The reception of this signal is undertaken with a superheterodyne detector using an intermediate frequency of 110 kHz. What is the appropriate local oscillator frequency? (e) Demodulation of this type of signal is usually accomplished using an envelope detector. Describe the principles of operation of an envelope detector and sketch an example circuit. (f) What considerations should be made about the component values in the design of an envelope detector in order to demodulate the signal after shifting to the intermediate frequency? Relative unitsS

4. For an AM DSBFC modulator with a carrier frequency fc = 100 kHz and a maximum modulating signal fm(max) = 5kHz, determine: a. Frequency limits for the upper and lower sidebands; b. Bandwidth; c. Upper and lower side frequencies produced when the modulating signal is a single frequency 3-kHz tone; Then d. Sketch the output frequency spectrum.

Q7. Figure Q7(a) shows the spectrum of a frequency modulated waveform with a sinusoidal modulation. 12 4.8 5.0 5.2 5.4 5.6 5.8 6.0 Frequency/MHz Figure Q7: (a) Spectrum of a frequency modulated waveform with a sinusoidal modulation. (a) Is this modulated waveform described as narrowband or as wideband? (b) What is the value of the carrier frequency? (c) What is the value of the modulation frequency? (d) Determine the value of the peak frequency deviation. Plots of Bessel functions of the first kind are provided below in Figure Q7(b) to assist you. (e) Estimate the fraction of the total signal power at the carrier frequency. (f) Detection of such a frequency modulated signal is usually accomplished with the use of a discriminator. Describe the function of a discriminator. (g) What is the equivalent AM modulation index obtained if this signal in Figure Q7(a) is demodulated with a high-pass RC filter discriminator? J„(x) 1.0 0.8 0.6 0.4 0.2 -0.2 -0.4 Figure Q7: (b) Bessel functions of the…

Q2] The following code (11001010) produced from the PCM system. (a) Draw the Polar NRZ line coder waveform, and calculate its average (DC) voltage. (b) Draw the Manchester line coder waveform, and calculate its average (DC) voltage. (c) Compare between the two-line coder schemes in DC values, and in bandwidth.

q4-  In spread spectrum communications, a pseudo-noise (PN) sequence converts _______ signal to ______ signalSelect one option:   a. unmodulated, modulated b. narrowband, wideband c. none of other answers d. wideband, narrowband