# Oscillator Phase Noise MCQ’s

This set of RF & Microwave Circuit Design Multiple Choice Questions & Answers (MCQs) focuses on “Oscillator Phase Noise”.

1. ____________ due to random fluctuations caused by thermal and other noise sources appear as broad continuous distribution localized about the output signal.
a) Phase noise
b) White noise
c) Thermal noise
d) Shot noise

2. The phase variation for an oscillator or synthesizer is given by:
a) ∆f*sin ωmt/ fm
b) ∆f / fm
c) Sin ωmt/ fm
d) None of the mentioned

3. A practical oscillator has a frequency spectrum consisting of a single delta function at its operating frequency.
a) True
b) False

4. The expression for phase noise in an oscillator is given by:
a) θrms2
b) θrms2/√2
c) θrms2/2
d) θrms2/ 3

5. Noise power versus frequency for an amplifier has spikes at the operating frequency without the application of an input voltage.
a) True
b) False

6. At higher frequencies of operation of an oscillator, induced noise is mostly:
a) Thermal noise
b) White noise
c) Shot noise
d) Flicker noise

7. Phase noise at the output of an oscillator is given by:
a) kBFGT0
b) kT0F/Pc
c) kT0F/Pc
d) None of the mentioned

8. An idealized power spectral density of amplifier has a straight line parallel to X axis and the noise is constant at all frequencies.
a) True
b) False

9. A GSM cellular telephone standard requires a minimum of 9 dB rejection of interfering signal levels of -23 dBm at 3 MHz from the carrier, -33 dBm at 1.6 MHz from the carrier, and -43 dBm at 0.6 MHz from the carrier, for a carrier level of -99 dBm. Determine the required local oscillator phase noise at 3 MHz carrier frequency offset.
a) -138 dBc/Hz
b) -128 dBc/Hz
c) -118 dBc/Hz
d) None of the mentioned

10. The most affected parameter of a receiver by the phase noise is signal to noise ratio.
a) True
b) False