10 Analogue Communication Interview Questions (With Answers)

By Indeed Editorial Team

Published 25 October 2022

The Indeed Editorial Team comprises a diverse and talented team of writers, researchers and subject matter experts equipped with Indeed's data and insights to deliver useful tips to help guide your career journey.

Analogue communication transfers information through the use of continuous impulses to send sound, image, video, electrons and other data. Analogue interview questions are about basic and in-depth concepts related to analogue communication systems. Interviewers may ask these questions to analyse your technical, theoretical and practical knowledge and preparing answers in advance can help you create a positive impression. In this article, we discuss 10 frequently asked analogue communication interview questions, along with their sample answers.

10 Analogue Communication Interview Questions With Sample Answer

Here are 10 analogue communication interview questions that hiring managers can ask in a technical interview, along with their sample answers to help prepare for your next interview:

1. What are the basic components of a communication system? How would you define an analogue signal?

Analogue communication is the transfer of data between a sender and a receiver with the help of an analogue signal. Analogue communication combines several elements to establish a network between the sender and the receiver. In your response, you can explain these elements and discuss the continuous nature of the signal, along with an example.

Example: 'Communication refers to the sending, receiving and processing of information between two or more entities or devices. Information source, input transducer, transmitter, communication channel, receiver, output transducer and destination are some fundamental parts of a communication system. Any continuous signal similar to another quantity is an analogue signal. For instance, the instantaneous signal voltage of an analogue audio signal continuously changes with the sound wave pressure.'

Related: How The Communication Process Works (Example Included)

2. What are the different types of signals? Explain periodic and non-periodic signals.

Signals can be of different types. For instance, a periodic signal has a definite pattern and repeats itself at regular intervals. Non-periodic signals may not repeat themselves. In your answer, you can explain the different types of signals and highlight the primary difference between periodic and non-periodic signals.

Example: 'Signals can be of six types, continuous time and discrete time signals, deterministic and non-deterministic signals, even and odd signals, periodic and aperiodic signals, energy and power signals and lastly, real and imaginary signals. If a signal repeats itself at regular intervals and follows a clear pattern, it is a periodic signal. Aperiodic or non-periodic signals do not occur at regular intervals of time.'

3. What is modulation, and what are its advantages?

Modulation is changing the carrier signal's parameters concerning the modulating signal's instantaneous value. For this reason, analogue signals are easier to process and are better suited for audio and video transmission. Your answer can explain this and other advantages of modulation in analogue communication.

Example: 'Modulation involves incorporating information into an electrical or optical carrier signal for the process of transforming data into radio waves. Electromagnetic transmissions such as radio waves, lasers and computer networks use modulation. Implementing modulation in communication systems has several benefits, including a reduction in the antenna size, zero signal mixing, a wider spectrum of communication, multiplexing of signals, the possibility of an adjustable bandwidth and improved reception quality.'

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4. What are the different types of modulation?

There are two basic types of modulation, analogue and digital. Analogue modulation is of three different subtypes. You can mention these three types and briefly explain each of them while answering this question.

Example: 'There are three basic modulation types: amplitude modulation, frequency modulation and phase modulation. Amplitude modulation is frequently used in electronic communication to convey data across a radio carrier wave. Frequency modulation changes the wave's instantaneous frequency by encoding information in a carrier wave. Phase modulation prepares communication signals for transmission. It transforms a message signal into fluctuations in a carrier wave's instantaneous phase.'

5. What is the square law modulator?

The square law diode modulation utilises the non-linear current-voltage characteristics of the diode. As the current-voltage characteristic of diodes is highly non-linear in the low voltage region, this approach is appropriate for low voltage levels. The diode functions in this nonlinear area for this application. While answering this question, you can define the concept and mention what a demodulator is to demonstrate that you understand both concepts clearly.

Example: 'The square law is the input-output relationship of the modulation device. Square law modulators have non-linear current-voltage characteristics and generate amplitude modulation. Since modulation transmits the audio signal farther to a receiver at the broadcasting station, extracting the audio signal from the modulated wave after the radio receiver receives it is essential. This is the process that takes place in the radio receiver and is known as demodulation.'

Related: 25 Interview Questions In Electronics (With Example Answers)

6. What is sampling?

Interviewers may ask this question to analyse if you can calculate the right rate of transmission to prevent loss of information. For signals with high-frequency components, it is necessary to sample at a higher rate to avoid data loss. In your response, you can define the concept of sampling and explain why it is important.

Example: 'Sampling is an analogue communication technique that transforms continuous-time signals into a series of discrete-time signals. The value of the signal is measured at specific time intervals to keep track. This process helps convert incoming data into a suitable rate of transmission to prevent any data losses. It is essential to sample the signal at twice its maximum frequency to retain all of its data.'

Related: What Is A Biased Sample? (With Definition And Examples)

7. What is multiplexing? Name its types.

Multiplexing allows transmitting a multitude of signals to one medium. Multiple signals may require simultaneous handling through this channel, which can be a physical medium like a coaxial, metallic conductor, or wireless link. In your response, you can explain the concept of multiplexing and discuss how it works.

Example: 'Multiplexing is a technique used in telecommunications and computer networks to combine several analogue or digital signals into a single signal via a common medium. There are two types of multiplexing, frequency division and time division multiplexing. In frequency division multiplexing, each user has a fixed frequency band that spans the entire channel bandwidth. The user receives this frequency continuously. In time division multiplexing, a pulse is present for a brief period, and there is typically no signal between them. Pulses from other channels may fill this space. Multiplexing can help reduce transmission costs.'

8. What is PAM, and what are its drawbacks?

Pulse amplitude modulation or PAM has a larger bandwidth than modulating signal frequency. The rectangular pulse train's amplitude receives adjustment as per the modulating signal's current value. Due to this, transmission occurs when different levels of power are available. For this question, you can briefly explain the concept of PAM and mention the key drawbacks.

Example: 'PAM or Pulse Amplitude Modulation is the process of transmitting data by changing the amplitudes of each electromagnetic pulse in a regular time sequence. The peak power of the modulating s/g is substantially higher since the pulse amplitudes vary. Since the amplitude fluctuates, transmission requires more bandwidth.'

Related: Guide: Career Options After Completing BSc In Physics

9. What is amplitude modulation?

Amplitude modulation is an important concept in analogue communications and is known for its ease of use. An analogue system requires modulation of the carrier amplitude and the receiver's detector to be a straightforward diode-based circuit. You can explain the basic concept of amplitude modulation to answer this question.

Example: 'Amplitude modulation is an electronic communication technology most frequently used to transmit data over a radio carrier wave. It changes the carrier wave's amplitude proportional to the message signal. The benefit of amplitude modification is that it can improve the strength of the signal without changing its original parameters.'

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10. What is the pass and stop band?

Wireless transmitters and receivers often use bandpass filters. The primary role of a filter is to limit the output signal's bandwidth to the transmission band. As a result, the transmitter cannot interfere with other stations. To answer this question, you can define a passband and a stop band and explain them with an example.

Example: 'Passband is the range of frequencies or wavelengths that can pass through a filter. For instance, a radio receiver has a bandpass filter that allows it to choose the desired frequency of the radio signal from the different radio waves picked up by its antenna. A stopband is a range of frequencies that fall within certain limits. Through a stopband, circuits either prevent the passage of signals or attenuate them beyond the minimum stopband attenuation level.'

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