Chapter 6: Single-Sideband Communications Systems - Review Notes

Reviewer and summary notes of the important concepts and formulas in Chapter 6 of the book "Introduction to Electronics Communications" by Wayne Tomasi.

Chapter 6: Single-Sideband Communications Systems

This is the summary notes of the important terms and concepts in Chapter 6 of the book "Electronic Communications System" by Wayne Tomasi. The notes are properly synchronized and concise for much better understanding of the book. Make sure to familiarize this review notes to increase the chance of passing the ECE Board Exam.

CHAPTER 6

SINGLE – SIDEBAND COMMUNICATIONS SYSTEMS

Items

Definitions

Terms

1

A form of amplitude modulation in which the carrier is transmitted at full power but only one of the sidebands is transmitted.

AM Single-sideband Full Carrier ( SSBFC )

2

A form of amplitude modulation in which the carrier is totally suppressed and one of the sidebands removed.

AM Single-sideband Suppressed Carrier ( SSBSC )

3

A form of amplitude modulation in which one sideband is totally removed and the carrier voltage is reduced to approximately 10% of its unmodulated amplitude. Sometimes called single-sideband reinserted carrier.

AM Single-sideband Reduced Carrier ( SSBRC )

4

It is the reinserted carrier in SSBRC for demodulation purposes.

Pilot Carrier

5

A form of amplitude modulation in which a single carrier frequency is independently modulated by two different modulating signals.

AM Independent Sideband ( ISB )

6

A form of amplitude modulation in which the carrier and one complete sideband are transmitted, but only part of the second sideband is transmitted.

AM Vestigial Sideband ( VSB )

7

________ is the picture portion of a commercial television broadcasting signal.

VSB System

8

Are obvious advantages of single-sideband suppressed- and reduced- carrier transmission over conventional double- sideband full-carrier transmission?

Bandwidth Conservation and Power Efficiency

9

This ratio determines the degree of intelligibility of a received signal.

Signal-to-Noise Ratio

10

With double-sideband transmission, the two sidebands and carrier may propagate through the transmission media by different paths and therefore, experience different transmission impairments. This condition is called ________.

Selective Fading

11

A condition in double-sideband transmission where one sideband is significantly attenuated.

Sideband Fading

12

A form of selective fading where there is a reduction of the carrier level of a 100%-modulated wave that will make the carrier voltage less than the vector sum of the two sidebands.

Carrier-Amplitude Fading

13

A condition where the relative positions of the carrier and sideband vectors of the received signal change, causing a decided change in the shape of the envelope, causing a severely distorted demodulated signal.

Carrier or Sideband Phase Shift

14

A product modulator where the output signal is the product of the modulating signal and the carrier.

AM Modulator

15

Modulator circuits that inherently remove the carrier during the modulation process.

DSBSC Modulators

16

A circuit that produces a double-sideband suppressed-carrier signal.

Balanced Modulator

17

A balanced modulator that is constructed with diodes and transformers. Sometimes called balanced lattice modulator.

Balanced Ring Modulator

18

The small carrier component that is always present in the output signal of a balanced modulator.

Carrier Leak

19

The operation of this balanced modulator as the balanced ring modulator is completely dependent on the switching action of diodes D1 through D4 under the influence of the carrier and modulating signal voltages.

Balanced Bridge Modulator

20

A double-balanced modulator/demodulator that produces an output signal that is proportional to the product of its input signals.

LM1497 / 1596 Balanced Modulator IC

21

The circuit where the carrier is reinserted.

Linear Summer

22

Three methods for single-sideband generation.

Filter, Phase-Shift, and Third Method

23

Types of single-sideband filters.

Crystal Lattice, Ceramic, Mechanical, Saw Filters

24

A mechanically resonant transducer that receives electrical energy, converts it to mechanical vibrations, and then converts the vibrations back to electrical energy at its output.

Mechanical Filter

25

Filters that use acoustic energy rather than electro-mechanical energy to provide excellent performance for precise bandpass filtering.

Surface Acoustic Wave Filters

26

Reflected energy that cancels and attenuates the incident wave energy.

Heterodyne

27

Reflected energy that aids the incident wave energy.

Constructive Interference

28

A transducer which launches the acoustic wave in only one direction.

Unidirectional Transducer

29

Any difference between the transmit and receive local oscillator frequencies produces a _______ in the demodulated information signal.

frequency offset error

30

Fifty hertz or more offset is distinguishable by a normal listener as a _______.

tonal variation

31

A narrowband PLL that tracks the pilot carrier in the composite SSBRC receiver signal and uses the recovered carrier to generate coherent local oscillator frequencies in the synthesizer.

Carrier Recovery Circuit

32

An SSB receiver that uses a PLL carrier recovery circuit and a frequency synthesizer to produce coherent local and beat frequency oscillator frequencies.

Multichannel Pilto Carrier

33

Systems that provide narrowband voice communications for land-mobile services with nearly the quality achieved with FM systems and do it using less than one-third the bandwidth.

Amplitude-Compandoring Single-Sideband ( ACSSB )

34

The process of combining transmissions from more than one source and transmitting them over a common facility, such as metallic or optical fiber cable or a radio-frequency channel.

Multiplexing

35

A transmission that can be used to combine hundreds or even thousands of narrowband channels into single, composite wideband channel without the channels interfering with each other.

Single-Sideband Suppressed-Carrier Transmission

36

Single-sideband transmitters are rated in ________ and ________.

Peak Envelope Power ( PEP ) & Peak Envelope Voltage ( PEV )

Complete List of Reviewers in Electronic Communications System per Chapter

Important List of Communications Engineering Materials


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