# Analog Communication Systems · Communications · GATE ECE

Start Practice## Marks 1

GATE ECE 2022

Consider an FM broadcast that employs the pre-emphasis filter with frequency response
$${H_{pe}}(\omega ) = 1 + {{j\omega } \over {{\omega _0}}}$$,
wh...

GATE ECE 2016 Set 3

For a superheterodyne receiver, the intermediate frequency is 15 MHz and the local oscillator frequency
is 3.5 GHz. If the frequency of the received s...

GATE ECE 2016 Set 1

A super heterodyne receiver operates in the frequency range of 58 MHz – 68 MHz. The
intermediate frequency f1F and local oscillator frequency fL0 are ...

GATE ECE 2015 Set 1

Consider the signal
$$s\left(t\right)\;=\;m\left(t\right)\;\cos\left(2{\mathrm{πf}}_\mathrm c\mathrm t\right)\;+\widehat m\left(t\right)\;\sin\left(2\...

GATE ECE 2014 Set 3

Consider an FM signal $$f\left(t\right)\;=\;\cos\left[2{\mathrm{πf}}_\mathrm c\mathrm t\;+\;{\mathrm\beta}_1\sin\;2{\mathrm{πf}}_1\mathrm t\;+\;{\math...

GATE ECE 2010

Consider an angle modulated signal x(t) = 6cos[2$$\mathrm\pi$$x106
t+2sin(8000$$\mathrm\pi$$t) +
4cos(8000$$\mathrm\pi$$t)] V. The average power of x(...

GATE ECE 2008

Consider the amplitude modulated (AM) signal $$A_c\cos\omega_ct\;+\;2\cos\omega_mt\;\cos\omega_ct$$. For
demodulating the signal using envelope detect...

GATE ECE 2005

Which of the following analog modulation scheme requires the minimum
transmitted power and minimum channel bandwidth?

GATE ECE 2004

An AM signal is detected using an envelope detector. The carrier frequency and
modulating signal frequency are 1 MHz and 2 KHz respectively. An approp...

GATE ECE 2004

An AM signal and a narrow-band FM signal with identical carriers, modulating
signals and modulation indices of 0.1 are added together. The resultant s...

GATE ECE 2002

A 1 MHz sinusoidal carrier is amplitude modulated by a symmetrical square wave
of period 100 µsec. Which of the following frequencies will NOT be pres...

GATE ECE 1999

A modulated signal is given by, $$s\left(t\right)=m_1\left(t\right)\cos\left(2{\mathrm{πf}}_\mathrm c\mathrm t\right)\;+m_2\left(t\right)\sin\left(2{\...

GATE ECE 1998

The image channel selectivity of super heterodyne receiver depends upon

GATE ECE 1998

A DSB-SC signal is generated using the carrier $$\cos\left(\omega_ct\;+\;\theta\right)$$ and modulating singal
x(t). The envelope of the DSB-SC signal...

GATE ECE 1994

$$v\left(t\right)\;=5\left[\cos\left(10^6\mathrm{πt}\right)\;-\;\sin\left(10^3\mathrm{πt}\right)\times\sin\left(10^6\mathrm{πt}\right)\right]$$ repres...

## Marks 2

GATE ECE 2017 Set 2

The un-modulated carrier power in an AM transmitter is 5kW. This carrier is modulated by a
sinusoidal modulating signal. The maximum percentage of mod...

GATE ECE 2017 Set 2

A modulating signal given By $$x\left(t\right)=5\sin\left(4\mathrm\pi10^3\mathrm t\;-\;10\mathrm{πcos}2\mathrm\pi10^3\mathrm t\right)$$ V
is fed to a ...

GATE ECE 2015 Set 1

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 figu...

GATE ECE 2012

The signal m(t) as shown is applied both to a phase modulator (with
kp
as the phase constant) and
a frequency modulator (with
kf
as the frequency cons...

GATE ECE 2008

The signal $$\cos\;\omega_ct\;+\;0.5\;\cos\;\omega_mt\;s\mathrm{in}\;\omega_ct$$ is

GATE ECE 2007

A Hilbert transformer is a

GATE ECE 2006

The diagonal clipping in Amplitude Demodulation (using envelope detector) can
be avoided if RC time-constant of the envelope detector satisfies the fo...

GATE ECE 2005

A device with input x(t) and output y(t) is characterized by: y(t) = x2(t). An FM signal with frequency deviation of 90 kHz and modulating signal band...

GATE ECE 2005

A carrier is phase modulated (PM) with frequency deviation of 10 kHz by a single
tone frequency of 1 kHz. If the single tone frequency is increased to...

GATE ECE 2004

Two sinusoidal signals of same amplitude and frequencies 10 kHz and 10.1 kHz
are added together. The combined signal is given to an ideal frequency de...

GATE ECE 2003

A DSB-SC signal is to be generated with a carrier frequency fc = 1MHz using a
nonlinear device with the input-output characteristic $$v_0=a_0v_i\;+\;a...

GATE ECE 2003

Let $$m\left(t\right)\;=\cos\left[\left(4\mathrm\pi\times10^3\right)t\right]$$ be the message signal and
$$c\left(t\right)\;=5\cos\left[2\mathrm\pi\ti...

GATE ECE 2003

Let $$m\left(t\right)\;=\cos\left[\left(4\mathrm\pi\times10^3\right)t\right]$$ be the message signal and
$$c\left(t\right)\;=5\cos\left[2\mathrm\pi\ti...

GATE ECE 2000

In an FM system, a carrier of 100 MHz is modulated by a sinusoidal signal of 5
KHz. The bandwidth by Carson’s approximation is 1 MHz. If y(t) = (modul...

GATE ECE 1993

Which of the following demodulator(s) can be used for demodulating the signal
$$x(t)\;=\;5\left(1+2\;\cos200\mathrm{πt}\right)\cos\;20000\;\mathrm{πt}...

GATE ECE 1993

A superheterodyne radio receiver with an intermediate frequency of 455 KHz is
tuned to a station operating at 1200 KHz. The associated image frequency...

GATE ECE 1992

The maximum power efficiency of an AM modulator is