Question 1

Frequency multiplication introduces ___________.

Accepted Answer

A) noise 
B) high reference frequencies 
C) drift problems 
D) output waveform 
A) noise 
B) high reference frequencies 
C) drift problems 
D) output waveform A

Question 2

Which of the following would be an application where a SAW filter would be used?

Accepted Answer

A) Miniaturized equipment 
B) Radar systems 
C) IF transformers 
D) Single-sideband systems 
A) Miniaturized equipment 
B) Radar systems 
C) IF transformers 
D) Single-sideband systems B

Question 3

What is the most common method of detecting an SSB signal?

Accepted Answer

A) Phase-locked loop 
B) Mechanical filter 
C) Product detector 
D) Voltage-controlled oscillator 
A) Phase-locked loop 
B) Mechanical filter 
C) Product detector 
D) Voltage-controlled oscillator C

Question 4

When are CMOS devices preferred?

Accepted Answer

A) When power consumption is a consideration. 
B) When much smaller spacing between output frequencies is necessary. 
C) When stability is directly governed by the stability of the reference input. 
D) When synthesizer frequency range is determined by the range of frequencies over which the VCO can operate. 
A) When power consumption is a consideration. 
B) When much smaller spacing between output frequencies is necessary. 
C) When stability is directly governed by the stability of the reference input. 
D) When synthesizer frequency range is determined by the range of frequencies over which the VCO can operate.

Question 5

A__________ is where the currents in the diodes and the currents in the transistors are the same.

Accepted Answer

A) current mirror 
B) push-pull 
C) cutoff 
D) conduction angle 
A) current mirror 
B) push-pull 
C) cutoff 
D) conduction angle

Question 6

Why are virtually all oscillators used in communications applications the feedback type?

Accepted Answer

A) They are capable of producing highly pure sine waves. 
B) The currents in the diodes and the currents in the transistors are the same. 
C) They use RC timing circuits to generate nonsinusoidal waveforms. 
D) They allow waveform distortion. 
A) They are capable of producing highly pure sine waves. 
B) The currents in the diodes and the currents in the transistors are the same. 
C) They use RC timing circuits to generate nonsinusoidal waveforms. 
D) They allow waveform distortion.

Question 7

Synthesizers are found in any device that must operate over a range of frequencies. Which of the following is an example of such a device?

Accepted Answer

A) Resonant tank circuits 
B) Cellular phones 
C) Rotary dial phones 
D) Landline phones 
A) Resonant tank circuits 
B) Cellular phones 
C) Rotary dial phones 
D) Landline phones

Question 8

Which of the following is needed in a reference oscillator to produce many frequencies?

Accepted Answer

A) Low-pass filter 
B) Varactor diode 
C) Phase comparator 
D) One crystal 
A) Low-pass filter 
B) Varactor diode 
C) Phase comparator 
D) One crystal

Question 9

The disadvantages of DDS include the limit on maximum output frequency and higher ___________.

Accepted Answer

A) cost 
B) output waveforms 
C) phase noise 
D) analog units 
A) cost 
B) output waveforms 
C) phase noise 
D) analog units

Question 10

The PLL is said to be in lock whenever the __________ can be matched to the reference.

Accepted Answer

A) free-running frequency 
B) VCO frequency 
C) capture range 
D) capacitance 
A) free-running frequency 
B) VCO frequency 
C) capture range 
D) capacitance

Question 11

___________ manifests itself as an opposition to current flow in ac circuits and is measured in ohms.

Accepted Answer

A) Resistance 
B) Reactance 
C) Impedance 
D) Capacitance 
A) Resistance 
B) Reactance 
C) Impedance 
D) Capacitance

Question 12

What is commonly used in single-sideband systems to attenuate the unwanted sideband?

Accepted Answer

A) Passband 
B) Stopband 
C) Wire leads 
D) Crystal filter 
A) Passband 
B) Stopband 
C) Wire leads 
D) Crystal filter

Question 13

Resonance is the condition where inductive and capacitive reactances are ___________.

Accepted Answer

A) equal 
B) reduced 
C) increased 
D) rejected 
A) equal 
B) reduced 
C) increased 
D) rejected

Question 14

From what material are ceramic filters normally constructed?

Accepted Answer

A) Quartz 
B) Crystal 
C) Lead zirconate-titanate 
D) Lithium niobate 
A) Quartz 
B) Crystal 
C) Lead zirconate-titanate 
D) Lithium niobate

Question 15

What type of filter is commonly used in single-sideband systems to attenuate the unwanted sideband?

Accepted Answer

A) Crystal 
B) Bandpass 
C) Mechanical 
D) Constant- k 
A) Crystal 
B) Bandpass 
C) Mechanical 
D) Constant- k

Question 16

The rate of attenuation is the steepness of the filter's response curve. What term is used to describe this rate?

Accepted Answer

A) Tank circuit 
B) Dissipation 
C) Roll-off 
D) Band-reject 
A) Tank circuit 
B) Dissipation 
C) Roll-off 
D) Band-reject

Question 17

To what does any modern,"frequency-agile" communication system owe its existence?

Accepted Answer

A) Crystal oscillators 
B) Amplifiers 
C) Parallel LC tank circuits 
D) Phase-locked loops 
A) Crystal oscillators 
B) Amplifiers 
C) Parallel LC tank circuits 
D) Phase-locked loops

Question 18

Amplifiers are classified by the amount of time during each input cycle that the active device within the circuit conducts __________.

Accepted Answer

A) harmonic content 
B) pulse-width modulation 
C) high linearity 
D) current 
A) harmonic content 
B) pulse-width modulation 
C) high linearity 
D) current

Question 19

Which of the following criteria would help you to choose the oscillator type for use in electronic circuits?

Accepted Answer

A) Input frequency required 
B) Frequency stability required 
C) Range of frequency output 
D) Allowable waveforms 
A) Input frequency required 
B) Frequency stability required 
C) Range of frequency output 
D) Allowable waveforms

Question 20

Which of the following is an advantage of mechanical filters?

Accepted Answer

A) New technology 
B) Extreme flexibility 
C) Excellent rejection characteristics 
D) Compatible with larger equipment 
A) New technology 
B) Extreme flexibility 
C) Excellent rejection characteristics 
D) Compatible with larger equipment

Frequency multiplication introduces ___________.

Which of the following would be an application where a SAW filter would be used?

What is the most common method of detecting an SSB signal?

When are CMOS devices preferred?

A__________ is where the currents in the diodes and the currents in the transistors are the same.

Why are virtually all oscillators used in communications applications the feedback type?

Synthesizers are found in any device that must operate over a range of frequencies. Which of the following is an example of such a device?

Which of the following is needed in a reference oscillator to produce many frequencies?

The disadvantages of DDS include the limit on maximum output frequency and higher ___________.

The PLL is said to be in lock whenever the __________ can be matched to the reference.

___________ manifests itself as an opposition to current flow in ac circuits and is measured in ohms.

What is commonly used in single-sideband systems to attenuate the unwanted sideband?

Resonance is the condition where inductive and capacitive reactances are ___________.

From what material are ceramic filters normally constructed?

What type of filter is commonly used in single-sideband systems to attenuate the unwanted sideband?

The rate of attenuation is the steepness of the filter's response curve. What term is used to describe this rate?

To what does any modern,"frequency-agile" communication system owe its existence?

Amplifiers are classified by the amount of time during each input cycle that the active device within the circuit conducts __________.

Which of the following criteria would help you to choose the oscillator type for use in electronic circuits?

Which of the following is an advantage of mechanical filters?

Fundamental Communications Concept

Amplitude Modulation

Angle Modulation

Transmitters

Receivers

Digital Communications Techniques

Digital Modulation and Demodulation

Telephone Networks

Wireless Communications Systems

Computer Communication and the Internet

Transmission Lines

Wave Propagation

Antennas

Waveguides and Radar

Fiber Optics

Filters

Exam 4: Communications Circuits

Frequency multiplication introduces ___________.

Which of the following would be an application where a SAW filter would be used?

What is the most common method of detecting an SSB signal?

When are CMOS devices preferred?

A__________ is where the currents in the diodes and the currents in the transistors are the same.

Why are virtually all oscillators used in communications applications the feedback type?

Synthesizers are found in any device that must operate over a range of frequencies. Which of the following is an example of such a device?

Which of the following is needed in a reference oscillator to produce many frequencies?

The disadvantages of DDS include the limit on maximum output frequency and higher ___________.

The PLL is said to be in lock whenever the __________ can be matched to the reference.

___________ manifests itself as an opposition to current flow in ac circuits and is measured in ohms.

What is commonly used in single-sideband systems to attenuate the unwanted sideband?

Resonance is the condition where inductive and capacitive reactances are ___________.

From what material are ceramic filters normally constructed?

What type of filter is commonly used in single-sideband systems to attenuate the unwanted sideband?

The rate of attenuation is the steepness of the filter's response curve. What term is used to describe this rate?

To what does any modern,"frequency-agile" communication system owe its existence?

Amplifiers are classified by the amount of time during each input cycle that the active device within the circuit conducts __________.

Which of the following criteria would help you to choose the oscillator type for use in electronic circuits?

Which of the following is an advantage of mechanical filters?

Fundamental Communications Concept

Amplitude Modulation

Angle Modulation

Transmitters

Receivers

Digital Communications Techniques

Digital Modulation and Demodulation

Telephone Networks

Wireless Communications Systems

Computer Communication and the Internet

Transmission Lines

Wave Propagation

Antennas

Waveguides and Radar

Fiber Optics

Filters