BSECE Board Examination Reviewer - Principles of Communications

Comprehensive vocabulary flashcards based on the BSECE Principles of Communications board examination reviewer transcript, covering definitions, inventors, technical standards, and mathematical concepts.

Harmonic

Frequencies that are exact multiples of the fundamental frequency.

Information Signal

The signal which is superimposed on a high-frequency sine wave; also known as the modulating signal.

Power

The rate at which energy is used, often expressed in watts.

J. Fourier

The mathematician who developed the mathematical solution to a complex repetitive waveform.

Frequency Spectrum

The entire range of frequencies of electromagnetic radiation.

Communications System Purpose

To provide an acceptable replica of the information at the designation point.

NO RY

Nomenclature standing for Normally Open Relay.

Class A Bias

The class of bias that should produce the least harmonics.

Class B Linear RF AM Amplifier Efficiency

An approximate efficiency of $50\%$.

Duplexer

A device used to connect a receiver and a transmitter to the same antenna.

Carrier Signal

A high-frequency signal that has a constant peak amplitude.

Period

The time required to complete one cycle of a wave.

Bandwidth

The range of frequencies represented in a signal.

Heterodyning

A term essentially synonymous with beating.

Wave Trap

A resonant circuit tuned to reject an undesired signal by reducing gain at the trap frequency.

Frequency Domain

The representation of a waveform such that its amplitude is displayed as a function of frequency.

ALC

Automatic Level Control.

Demodulator

The circuit that changes modulated RF (Radio Frequency) back to AF (Audio Frequency).

EHF Band

Extremely High Frequency band, which is in the radio spectrum range of $30$ to $300\,GHz$.

Edison

The inventor who created the phonograph in 1877 to make a permanent record of sound.

Logic Analyzer

A device designed to display the signal state of many lines simultaneously.

AGC

Automatic Gain Control; a circuit that automatically holds the level or strength of a signal at a predetermined level to compensate for variations due to fading.

Marconi

The individual who developed the wireless telegraph.

Quartz

The kind of crystal typically used in oscillators.

Frequency Discriminator

A circuit used specifically for detecting FM signals.

VOX

Voice-operated transmission.

Modulation

The process of impressing information signals onto a high-frequency carrier.

SI Unit of Magnetic Field Intensity

$Ampere/meter$.

ANSI

American National Standards Institute.

Balanced Modulator

The circuit that performs the suppression of the carrier signal.

Applegate Diagram

A diagram showing the relationship between RF signal phase and maximum bunching of the electron beam in velocity-modulated devices.

VIR

Vertical Interval Reference.

Fourier's Theorem

States that any periodic function is represented by the sum of a number of sinusoidal variations of different amplitudes, frequencies, and phases.

AFC

Automatic Frequency Control.

Transceiver

A device which can perform the function of both a transmitter and a receiver.

Communications

The sending, receiving, and processing of information by electronic means.

WDM

Wavelength Division Multiplexing.

Telegraph

The invention from 1844 that represented the big breakthrough in electric communications.

$$40\,dBW$$

A power level equivalent to $10000\,W$.