General · correct answers only, in question-pool order.
A bleeder resistor provides a discharge path for power-supply filter capacitors after power is removed, reducing the time that dangerous stored voltage remains.
Power-supply filter networks commonly use capacitors and inductors to smooth rectified DC and reduce ripple.
A center-tapped full-wave rectifier uses two diodes, one for each half of the transformer secondary, so both halves of the AC cycle contribute to the DC output.
A half-wave rectifier uses one diode and conducts during only one half of each AC cycle.
A half-wave rectifier converts one half of the sine-wave cycle to DC, which is 180 degrees of the 360-degree cycle.
A full-wave rectifier uses both halves of the AC waveform, so all 360 degrees of each cycle are converted to pulsating DC.
Because a full-wave rectifier uses both halves of the AC cycle, its unfiltered output consists of DC pulses at twice the input AC frequency.
Switchmode supplies operate at high internal switching frequencies, allowing transformers, inductors, and capacitors to be much smaller than comparable 50/60-Hz linear-supply components.
In Figure G7-1, symbol 1 is the field-effect transistor symbol.
In Figure G7-1, symbol 5 is the Zener diode symbol.
In Figure G7-1, symbol 2 is the NPN junction transistor symbol.
In Figure G7-1, symbol 6 represents a solid-core transformer.
In Figure G7-1, symbol 7 is the tapped-inductor symbol.
Neutralization feeds back a small signal with the proper phase and amplitude to cancel unwanted internal feedback that could make an amplifier oscillate by itself.
Class C amplifiers conduct for less than half of each RF cycle and can achieve the highest efficiency among the amplifier classes listed.
A two-input AND gate produces a high output only when both inputs are high.
A Class A amplifying device conducts for the entire signal cycle, or 100 percent of the time.
A three-bit binary counter has 2³ possible states, which equals eight.
A shift register is a clocked chain of digital storage stages that moves data one step through the array with each clock event.
A sine-wave oscillator requires gain plus frequency-selective feedback. The filter establishes the frequency while the amplifier supplies the gain needed to sustain oscillation.
RF power-amplifier efficiency is the useful RF output power divided by the DC input power.
The resonant tank circuit sets the frequency of an LC oscillator, so its inductance and capacitance determine the oscillation frequency.
A linear amplifier reproduces the input waveform at greater amplitude without intentionally changing its shape.
Class C amplification is appropriate for FM because FM is a constant-envelope mode; the information is carried by frequency changes rather than amplitude variations.
A balanced modulator produces both sidebands. A filter selects the desired sideband and rejects the other to create an SSB signal.
A balanced modulator suppresses the carrier while producing upper and lower sidebands, resulting in double-sideband suppressed-carrier RF.
An impedance-matching transformer at a transmitter output makes the transmitter and feed line see the impedance they are designed to work with.
A product detector mixes an incoming SSB signal with a locally generated carrier so the original audio modulation can be recovered.
A direct digital synthesizer generates selectable frequencies digitally while deriving its stability from a precise reference oscillator, often crystal controlled.
DSP filters can implement many different bandwidths and response shapes in software without changing physical analog components.
Insertion loss is the attenuation a filter introduces to signals that are supposed to pass through its passband.
The official G7C08 source identifies input amplifier gain as one of the parameters that affects receiver sensitivity.
The official G7C08 source identifies demodulator stage bandwidth as one of the parameters that affects receiver sensitivity.
The official G7C08 source identifies input amplifier noise figure as one of the parameters that affects receiver sensitivity.
I and Q signals are in quadrature, meaning they differ in phase by 90 degrees.
With I-Q modulation, suitable digital processing can synthesize many modulation types from the same underlying hardware.
The official G7C11 source identifies filtering as a function that can be performed in software in an SDR.
The official G7C11 source identifies detection as a function that can be performed in software in an SDR.
The official G7C11 source identifies modulation as a function that can be performed in software in an SDR.
A low-pass filter's cutoff frequency is the point where output power has fallen below one-half of the input power, corresponding to about -3 dB.
Ultimate rejection describes the greatest attenuation a filter can provide to unwanted signals far outside the passband.
Band-pass filter bandwidth is measured between its lower and upper half-power, or -3 dB, frequencies.