ELECTRONIC CONSTRUCTION TECHNIQUES
50 questions available
Questions
Based on the graph of collector-to-base capacitance versus collector voltage in Figure 13.3, what is the approximate Ccb for a 2N3725 transistor at a collector voltage of 10 volts?
View answer and explanationWhat is the typical range for the exponent 'n' in the formula C = k(V - Vd)^n, which describes how the capacitance of a reverse-biased semiconductor junction in a transistor varies with voltage?
View answer and explanationAccording to the graph of gain-bandwidth product (fT) versus collector current (Ic) in Figure 13.4, at what collector current does the 2N3904 transistor reach its peak fT?
View answer and explanationWhat is the primary reason a transistor manufacturer typically specifies the transition frequency, fT?
View answer and explanationIn the high-frequency amplifier analysis example using a 2N4124 transistor, what phenomenon is identified as the dominant factor that severely limits the high-frequency rolloff?
View answer and explanationFor the 2N4124 amplifier example, with a low-frequency voltage gain of 100 and a feedback capacitance Ccb of 2.4 pF, what is the calculated effective input capacitance due to the Miller effect?
View answer and explanationWhich high-frequency amplifier configuration is described as a common-emitter stage driving a common-base stage, which eliminates the Miller effect by pinning the emitter of the second transistor with a fixed base voltage?
View answer and explanationIn the wideband design example from section 13.05, which uses the 2N5179 transistor in a configuration designed to eliminate Miller rolloff, what is identified as the ultimate performance-limiting factor?
View answer and explanationWhat is the specified collector-to-base capacitance (Ccb) for the 2N5179 transistor at a bias of 2 volts, as used in the wideband differential amplifier example?
View answer and explanationIn the performance analysis of the wideband amplifier design example in section 13.05, at what frequency was the overall circuit's output estimated to be down by 3dB?
View answer and explanationWhat phenomenon in high-frequency amplifiers is known as 'pole splitting'?
View answer and explanationThe 2N5179 transistor is specified with a 'collector-base time constant' (r'b * Ccb) of 3.5 picoseconds. Given its Ccb is 0.5 picofarads, what is the implied base 'spreading' resistance (r'b)?
View answer and explanationWhat are the typical input and output impedance levels for prepackaged modular RF amplifiers, designed for convenient system integration?
View answer and explanationWhat semiconductor technologies are mentioned for creating wideband amplifiers that operate at frequencies up to 18 GHz and beyond?
View answer and explanationAccording to the caption for Figure 13.14, which of the following is NOT part of the described hybrid construction technique?
View answer and explanationWhat method is invariably used to measure the noise figure or noise temperature in microwave amplifiers?
View answer and explanationRecent designs employing high-electron-mobility FETs (HEMTs) have achieved what phenomenal noise temperature at 8.5 GHz?
View answer and explanationAccording to the text, what is the approximate maximum transition frequency (fT) one can expect from an operational amplifier if an input offset of 10 mV or so can be tolerated?
View answer and explanationAccording to Table 13.1 (RF Transistors), what is the typical transition frequency (fT) for the 2N5179 transistor when operated at a collector current of 10mA?
View answer and explanationBased on the comments in Table 13.1 (RF Transistors), which device is specifically identified as a 'micropower' transistor?
View answer and explanationWhat is the typical slew rate specified for the AD844A wideband op-amp in Table 13.2?
View answer and explanationIn Table 13.2 (Wideband Op-Amps), what is the comment provided for the EL2022 op-amp?
View answer and explanationWhat is the fundamental rule for connecting a load to a transmission line in radiofrequency circuits to ensure proper operation and signal transfer?
View answer and explanationWhat is the typical characteristic impedance range for parallel-conductor transmission lines?
View answer and explanationOn a mismatched transmission line, what happens to a wave when it reaches a termination that is an open circuit?
View answer and explanationA transmission line that is an integral number of half wavelengths long is terminated in an impedance Z_load. What input impedance Z_in does this line present?
View answer and explanationWhat is a primary advantage of using a broadband transmission-line transformer over a conventional wire-wound transformer at high frequencies?
View answer and explanationIn the context of tuned RF amplifiers, what is the technique of 'neutralization' used for?
View answer and explanationFor creating tunable oscillators for gigahertz frequencies, what component does a YIG-tuned oscillator use as its magnetically tunable resonant element?
View answer and explanationTo achieve the highest level of frequency stability for timekeeping, what type of oscillator is used?
View answer and explanationIn the context of radiofrequency circuits, what is a 'mixer'?
View answer and explanationWhat distinguishes a 'balanced mixer' from a simple nonlinear mixer like a diode?
View answer and explanationWhat type of RF passive device, employing exotic ferrite materials and magnetic fields, is designed to transmit waves in only one direction between its two ports?
View answer and explanationWhat type of filter is mentioned as being 'extremely important' for setting receiver selectivity and is made from piezoelectric or mechanical resonators?
View answer and explanationWhat is 'synchronous detection', also called 'homodyne detection'?
View answer and explanationWhat is the primary characteristic of the bolometric method for measuring RF power?
View answer and explanationIn amplitude modulation (AM), what does the spectrum of a carrier modulated by a single sine wave consist of?
View answer and explanationWhat is the primary function of a superheterodyne ('superhet') receiver?
View answer and explanationIn a superheterodyne receiver, what is the 'image' frequency?
View answer and explanationWhat is the primary advantage of single-sideband (SSB) modulation compared to standard amplitude modulation (AM)?
View answer and explanationIn FM broadcasting, what is the peak frequency deviation (fdev) used, and what approximate bandwidth does this result in for each station?
View answer and explanationWhich method of detecting FM signals is described as a parallel LC circuit tuned off to one side of the IF, which converts frequency deviation into amplitude modulation?
View answer and explanationAccording to the Shannon sampling theorem, which makes digital transmission of analog signals possible, a band-limited waveform is fully described by sampling its amplitude at what rate?
View answer and explanationIn pulse-code modulation (PCM), what makes it particularly useful in repeater applications where a signal must be amplified multiple times?
View answer and explanationWhat is the primary purpose of using RF 'chokes' and shielded 'feedthrough capacitors' on power supply lines entering a shielded RF enclosure?
View answer and explanationWhen building circuits for VHF and UHF frequencies, why is it absolutely essential to keep component leads as short as possible?
View answer and explanationIn the context of exotic RF devices, what are 'paramps' (parametric amplifiers) used for?
View answer and explanationWhich exotic diodes are described as being used extensively at UHF and microwave frequencies as low-power oscillators in the 5-100 GHz range?
View answer and explanationIn the transistor model for high-speed switching, what is the 'storage time' (ts)?
View answer and explanationWhat is the purpose of using a Schottky diode as a 'Baker clamp' from a transistor's base to its collector in a high-speed switching circuit?
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