Category: Telecommunication Systems
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What is the difference between Broadband and Baseband Transmission?
Broadband transmission is used for a network in which information is modulated onto a radio frequency carrier which passes through the transmission medium such as a coaxial cable. Broadband transmission allows a number of modulated radio frequency carriers to be simultaneously transmitted and therefore offers a multichannel capability. Normally the topology of broadband LANs is…
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Tuned Amplifier Applications
A tuned amplifier operates over a band of frequencies centered on a resonant frequency. Its two main requirements are to provide high gain and good selectivity. We have several applications in telecommunications systems where it is necessary to amplify a narrow band of frequencies centred on one frequency. A typical example is shown in the…
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Applications of Filters in Telecommunication Systems
Electronic filters have many applications in the telecommunication and data communications industry. For example, they are used in a multichannel communication system employing a technique known as time-division multiplexing (TDM). In this system, several channels are transmitted through a medium such as optical fiber or through a co-axial cable or waveguide. Multiplexing means combining several…
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Features of FM Receivers
FM receivers employ heterodyne principle. The FM broadcast signals lie in the frequency range between 88 MHz and 108 MHz. The intermediate frequency (IF) of a FM receiver is 10.7 MHz which is much higher than the IF value of 455 kHz in AM receivers. Let’s consider the block diagram of an FM receiver below:…
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Radio Frequency (RF) and Microwave – Multiple Choice Questions & Answers (MCQ3)
The Answers have been provided at the end of Questions. Q1. What is the approximate bandwidth of radio frequency (RF) electromagnetic waves? A. 300 Hz to 300 GHz B. 20 Hz to 20 kHz C. 300 Hz to 3000 GHz D. 300 MHz to 300 GHz Q2. In spectral analysis the following factors are considered…
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RF Power and Voltage Measurement
RF system’s output power level is often the key factor in the design and ultimately the performance of virtually all radio frequency and microwave equipment. For the measurement of average power, a sensor along with a calibrated power meter is connected with the RF transmitter. Initially, if the output of the sensor is switched OFF…
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Types of AM Radio Receivers
A radio receiver is a device which reproduces the modulated or radio waves into sound waves. The radio receivers used in reproducing amplitude modulated signals are called AM radio receivers. So as to reproduce the AM wave into sound waves, every radio receiver must perform the following functions: Related: General Principles of Radio Broadcasting, Transmission…
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Demodulation in Telecommunication Systems
Demodulation is the process of recovering the audio signal from the modulated wave. Demodulation is also known as detection in communication systems. Why Demodulation is needed in Telecommunication Systems Amplitude modulated wave consists of carrier and sideband frequencies. The audio signal is contained in the sideband frequencies which are radio frequencies. If the modulated wave…
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Modulation in Communication Systems
Introduction Modulation is the process of changing some characteristics (e.g. Amplitude, Frequency, or Phase) of a carrier wave in accordance with the intensity of the message signal. Modulation means to ‘’change’’. In Modulation, some characteristics of the carrier wave is changed in accordance with the intensity i.e. amplitude of the message signal. The resultant wave…
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RF Scalar and Vector Network Analyzers
The RF network analyzer is an active test instrument which generates a signal that is applied to the device under test, and then it measures the response. Functions of a RF Network Analyzer Signal Separation The signal separation element is often called the test set. It provides two functions: Receiver and Signal Detection When signal…