Chapter 2: Electronic Fundamentals for Communications Flashcards
______ means amplification. It is the ratio of a circuit’s output to its input.
Gain
An amplifier is _____ when two or more stages are connected together.
Cascaded
_____ refers to a loss introduced by a circuit or component. If the output signal is lower in amplitude than the input, the circuit has loss or attenuation.
Attenuation
The ______ is a unit of measure used to express the gain or loss of a circuit.
Decibel
The ____ is the number obtained when the base is raised to the logarithm which is the exponent.
Antilog
When a _______ value is computed by comparing a power value to 1mW, the result is a value called the dBm.
Decibel
The value ___ is a decibel gain attenuation figure where the reference is the carrier.
dBc
Virtually all communications equipment contains _________ made up of inductors and capacitors that ___________at specific frequencies.
Tuned circuits
Resonate
Opposition to alternating current flow offered by coils and capacitors is known as __________.
Reactance
_______ is the tendency of electrons flowing is a conductor to flow near and on the outer surface of the conductor.
Skin effect
A ___________________ circuit is made up of inductance, capacitance and resistance connected in series.
Series resonant
The ____ of a series resonant circuit is the narrow frequency range over which the current is highest.
Bandwidth
________ are the current levels at which the frequency response is 70.7% of the peak value of resonance.
Half power points
The ________ of a series resonant circuit is the ration of inductive reactance to the total circuit resistance.
Quality (Q)
________ is how a circuit responds to varying frequencies.
Selectivity
The _____ circuit is formed when the inductor and capacitor of a tuned circuit are connected in parallel with the applied voltage.
Parallel resonant
It is often referred to as a ______ and the circulating current is referred to as the tank current.
Tank ciircuit
A ____ is a frequency selective ciircuit.
Filter
___________ are created using components such as: resistor, capacitor and inductors that do not amplify.
Passive filters
Use amplifying devices such as transistors and Op-Amps.
Active filters
Filters only pass frequencies below a critical (cutoff) frequency.
Low-pass filters
Filters only pass frequencies above the cutoff frequency.
High-pass filters
Filters pass frequencies over a narrow range between lower and upper cutoff frequencies.
Bandpass filters
Filters reject or stop frequencies over a narrow range between lower and upper cutoff frequencies.
Band-reject filters
Filters pass all frequencies over a desired range but have a predictable phase shift characteristic.
All-pass filters
Use combinations of resistors and capacitors to achieve a desired frequency response.
RC filters
Use combinations of inductors and capacitors to achieve a desired frequency response.
LC filters
_____________ is the loss the filter introduces to the signals in the passband.
Insertion loss
________ is the resistive value of the load and source terminations of the filter.
Impedance
________ is a term used to describe the amplitude variation with frequency in the passband.
Ripple
____________ is the ratio of the stop bandwidth to the pass bandwidth of a bandpass filter.
Shape factor
A ______ is a frequency at which there is a high impedance in the circuit.
pole
____ is a term used to refer to a frequency at which there is zero impedance in the circuit.
Zero
__________ or time delay is the time it takes for a specific point on an input waveform to pass through the filter.
Envelope delay
_______ or attenuation rate is the rate of change of amplitude with frequency in a filter.
Roll-off
The __________ filter effect has maximum flatness in response in the passband and a uniform attenuation with frequency.
Butterworth filter
Has extremely good selectivity, and attenuation just outside the passband is very high, but has ripple in the passband.
Chebyshev filter
Produces greater attenuation out of the passband, but with higher ripple within and outside of the passband.
Cauer Elliptical
Provides the desired frequency response (i.e., low-pass, bandpass, etc.) but has a constant time delay in the passband
Bessel Thomson
A _____________ uses resonant vibrations of mechanical dishs to provide the selectivity.
Mechanical filter
_____________ are made of thin slivers of quartz crystal or certain other types of ceramic materials.
Crystal and ceramic filters
