3-D-031: Phase Locked Loops (PLLs); Voltage Controlled Oscillators (VCOs); Mixers
3-31D1:
What frequency synthesizer circuit uses a phase comparator, look-up table, digital-to-analog converter, and a low-pass antialias filter?
A direct digital synthesizer.
Phase-locked-loop synthesizer.
A diode-switching matrix synthesizer.
A hybrid synthesizer.
3-31D2:
A circuit that compares the output of a voltage-controlled oscillator (VCO) to a frequency standard and produces an error voltage that is then used to adjust the capacitance of a varactor diode used to control frequency in that same VCO is called what?
Phase-locked loop.
Doubly balanced mixer.
Differential voltage amplifier.
Variable frequency oscillator.
3-31D3:
RF input to a mixer is 200 MHz and the local oscillator frequency is 150 MHz. What output would you expect to see at the IF output prior to any filtering?
50, 150, 200 and 350 MHz.
50 MHz.
350 MHz.
50 and 350 MHz.
3-31D4:
What spectral impurity components might be generated by a phase-locked-loop synthesizer?
Broadband noise.
Spurs at discrete frequencies.
Random spurs which gradually drift up in frequency.
Digital conversion noise.
3-31D5:
In a direct digital synthesizer, what are the unwanted components on its output?
Spurs at discrete frequencies.
Broadband noise.
Digital conversion noise.
Nyquist limit noise pulses.
3-31D6:
What is the definition of a phase-locked loop (PLL) circuit?
A servo loop consisting of a phase detector, a low-pass filter and voltage-controlled oscillator.
A servo loop consisting of a ratio detector, reactance modulator, and voltage-controlled oscillator.
A circuit also known as a monostable multivibrator.
A circuit consisting of a precision push-pull amplifier with a differential input.
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