Which statement accurately describes pulse-width modulation (PWM)?
Explanation
This question requires differentiating the definition of PWM from other pulse-modulation schemes described in Section 13.20. PWM encodes information in the time duration (width) of the pulses.
Other questions
Which pulse-modulation scheme converts the instantaneous amplitude of a signal into a binary number for transmission as a serial string of bits?
What is the primary advantage of Pulse-Code Modulation (PCM) when transmitting signals over noisy channels?
In RF circuit construction, what is the primary reason for keeping component leads as short as possible?
What is the principle of amplification in a parametric amplifier?
Which electronic device is described as delivering the lowest noise of any amplifier?
What is the primary function of a Baker clamp (a Schottky clamping diode) in a high-speed switching circuit?
What is the typical output power delivered by Gunn diodes used as low-power oscillators in the 5-100GHz range?
In a transistor switch, what does the storage time (t_s) represent?
What is the effect of 'gold doping' in a transistor, as mentioned in the context of storage times?
In the open-collector bus driver example, what is the specified collector-base capacitance (Ccb) for the 2N5137 transistor at 10V?
What is the primary application for magnetrons?
According to the description of the open-collector bus driver example, what is the primary reason for the inferior performance of the 2N5137 transistor compared to the 2N4124?
For the compact disc digital audio standard mentioned, how many times per second is each stereo channel sampled?
What type of computer program, originated by L. W. Nagel, is specifically mentioned as a key tool for computer-aided analog modeling?
In the high-voltage driver example (Figure 13.55), what is the calculated collector rise time (10 percent to 90 percent)?
What is the function of using a double-sided PC board with one side used as a ground-plane in RF circuits?
What is a defining characteristic of a parametric amplifier's 'pump' signal, according to the pendulum analogy?
Which devices are described as behaving as voltage-variable resistances and are used to switch microwave signals on and off across a waveguide?
In the analysis of transistor rise time, what is the 'integrator-limited' rate of rise primarily caused by?
What is the primary purpose of using a 'speedup' capacitor across the base driving resistor in a high-speed switching circuit?
In the open-collector bus driver example (Figure 13.57), what is the integrator-limited rate of rise (dVc/dt) for the 2N4124 transistor?
Why are stripline and microstrip techniques used at very high frequencies (VHF and UHF)?
Present-day commercial GaAs FETs can deliver 28dB of gain at 10GHz with what noise figure?
What is the primary application of SNAP diodes mentioned in the text?
In the context of TTL bus drivers, why might a bus be terminated to a source of +3 volts instead of +5 volts or ground?
What is the primary function of shielded 'feedthrough capacitors' in RF circuit construction?
Which technology is particularly noted for its use in telemetry of images from space vehicles owing to its error-free properties?
What is a major limitation of using conventional capacitors at VHF and UHF frequencies?
In the photomultiplier preamp and discriminator circuit shown in Figure 13.60, what is the role of the differential amplifier Q2 and Q3?
What is the consequence of the long storage time (ts) in a transistor switch?
According to the Shannon sampling theorem, how can a band-limited waveform be fully described?
What is the specified hfe for the 2N5965 transistor used in the high-voltage driver circuit shown in Figure 13.55?
What is the function of IMPATT diodes as described in the text?
In the context of the open-collector bus driver analysis, what measured propagation delay (tPHL) was observed for the 2N4124 circuit?
What does the acronym 'Maser' stand for?
What is one of the primary challenges when building circuits at higher radio frequencies, such as VHF and UHF?
Which device is described as the 'heart of radar and microwave ovens'?
In the transistor switching model shown in Figure 13.50, which component is considered the 'all-important feedback capacitance'?
What does the waveform in Figure 13.52, showing the gate and drain of a MOSFET, illustrate?
In the context of the photomultiplier preamp circuit (Figure 13.60), why are the transistor quiescent currents set rather high?
What kind of RF amplifier is analogous to building up a pendulum's swing by pulling up and down on the string at twice its natural resonant frequency?
In the high-voltage driver example (Figure 13.55), what is the calculated fall time (tf)?
What is the primary function of varactor diodes in RF circuits?
In the open-collector bus driver example, what is the calculated propagation delay for the falling edge (tPHL) of the 2N5137 transistor?
What phenomenon in high-speed switching is caused by the extra injected minority carriers from the emitter needing to be swept from the base region after the drive signal is removed?
In the high-voltage driver circuit analysis in Figure 13.56, the rise is dominated by the time constant of the load capacitance and collector resistor, while the fall is dominated by what?
What is the primary characteristic of 'coded PCM'?
What is a key difference in the physical package of transistors intended for use at VHF and above?
In the photomultiplier preamp circuit (Figure 13.60), what is the function of the clamping diode D1?