GATE Communications: Analog Communications – Previous Year Questions
24 GATE previous year questions on Analog Communications (Communications, Electronics and Communication Engineering) with answers and explanations, from every paper.
- GATE 2015 EC Q32 – A sinusoidal signal of 2 kHz frequency is applied to a delta modulator. The sampling rate and step-size of the delta modulator are 20,000 samples per…
- GATE 2015 EC Q33 – Consider the signal s(t) = m(t)(2 f c t) + m(t)(2 f c t) where m(t) denotes the Hilbert transform of m(t) and the bandwidth of m(t) is very small…
- GATE 2015 EC Q61 – In the system shown in Figure (a), m(t) is a low-pass signal with bandwidth W Hz. The frequency response of the band-pass filter H(f) is shown in…
- GATE 2016 EC Q26 – The block diagram of a frequency synthesizer consisting of a Phase Locked Loop (PLL) and a divide-by-N counter (comprising 2, 4, 8, 16 outputs) is…
- GATE 2016 EC Q32 – A superheterodyne receiver operates in the frequency range of 58 MHz - 68 MHz. The intermediate frequency f IF and local oscillator frequency f LO are…
- GATE 2016 EC Q33 – The amplitude of a sinusoidal carrier is modulated by a single sinusoid to obtain the amplitude modulated signal s(t) = 5 1600 t + 20 1800 t + 5 2000…
- GATE 2016 EC Q62 – An antenna pointing in a certain direction has a noise temperature of 50 K. The ambient temperature is 290 K. The antenna is connected to a…
- GATE 2018 EC Q25 – Consider the following amplitude modulated signal: s(t)=(2000 t)+4(2400 t)+(2800 t). The ratio (accurate to three decimal places) of the power of the…
- GATE 2018 EC Q37 – Let c(t)=A c(2 f ct) and m(t)=(2 f mt). It is given that f c5f m. The signal c(t)+m(t) is applied to the input of a non-linear system, whose output v…
- GATE 2018 EC Q49 – The input 4\,sinc(2t) is fed to a Hilbert transformer to obtain y(t), as shown in the figure below. Here, sinc(x)=( x) x. The value (accurate to two…
- GATE 2019 EC Q32 – The baseband signal m(t) shown in the figure is phase-modulated to generate the PM signal (t)=(2 f ct+k\,m(t)). The time t on the x-axis in the figure…
- GATE 2020 EC Q52 – For the modulated signal x(t)=m(t)(2 f ct), the message signal m(t)=4(1000 t) and the carrier frequency f c is 1 MHz. The signal x(t) is passed…
- GATE 2020 EC Q57 – S PM(t) and S FM(t) as defined below, are the phase modulated and the frequency modulated waveforms, respectively, corresponding to the message signal…
- GATE 2021 EC Q32 – Consider a carrier signal which is amplitude modulated by a single-tone sinusoidal message signal with a modulation index of 50%. If the carrier and…
- GATE 2021 EC Q59 – A sinusoidal message signal having root mean square value of 4 V and frequency of 1 kHz is fed to a phase modulator with phase deviation constant 2…
- GATE 2021 EC Q60 – Consider a superheterodyne receiver tuned to 600 kHz. If the local oscillator feeds a 1000 kHz signal to the mixer, the image frequency (in integer)…
- GATE 2022 EC Q51 – Consider an FM broadcast that employs the pre-emphasis filter with frequency response H pe()=1+j 0, where 0=104 rad/sec. For the network shown in the…
- GATE 2023 EC Q27 – Let m(t) be a strictly band-limited signal with bandwidth B and energy E. Assuming 0=10B, the energy in the signal m(t) 0t is
- GATE 2023 EC Q45 – Let a frequency modulated (FM) signal x(t)=A( ct+k f -tm()d), where m(t) is a message signal of bandwidth W. It is passed through a non-linear system…
- GATE 2023 EC Q50 – Let x 1(t) and x 2(t) be two band-limited signals having bandwidth B=4103 rad/s each. In the figure below, the Nyquist sampling frequency, in rad/s,…
- GATE 2024 EC Q28 – An amplitude modulator has output (in Volts) s(t)=A(400 t)+B(360 t)+B(440 t). The carrier power normalized to 1\ resistance is 50 Watts. The ratio of…
- GATE 2025 EC Q14 – Consider a frequency-modulated (FM) signal f(t)=A c(2 f ct+3(2 f 1t)+4(6 f 1t)), where A c and f c are, respectively, the amplitude and frequency (in…
- GATE 2025 EC Q28 – Consider a message signal m(t) which is bandlimited to [-W,W], where W is in Hz. Consider the following two modulation schemes for the message signal:…
- GATE 2026 EC Q57 – Consider a real, narrowband signal x(t)=A(t)[2 f ct+(t)] where the maximum frequency components of A(t) and (t) are f M and f c\,(=1000f M),…