E8A Fourier analysis; RMS measurements; average RF power and peak envelope power (PEP); analog/digital conversion
- E8A01 (A)
What technique shows that a square wave is made up of a sine wave and its odd harmonics? #card
- A. Fourier analysis
- B. Vector analysis
- C. Numerical analysis
- D. Differential analysis
- E8A02 (A)
Which of the following is a type of analog-to-digital conversion? #card
- A. Successive approximation
- B. Harmonic regeneration
- C. Level shifting
- D. Phase reversal
- E8A03 (B)
Which of the following describes a signal in the time domain? #card
- A. Power at intervals of phase
- B. Amplitude at different times
- C. Frequency at different times
- D. Discrete impulses in time order
- E8A04 (B)
What is “dither” with respect to analog-to-digital converters? #card
- A. An abnormal condition where the converter cannot settle on a value to represent the signal
- B. A small amount of noise added to the input signal to reduce quantization noise
- C. An error caused by irregular quantization step size
- D. A method of decimation by randomly skipping samples
- E8A05 (D)
What is the benefit of making voltage measurements with a true-RMS calculating meter? #card
- A. An inverse Fourier transform can be used
- B. The signal’s RMS noise factor is also calculated
- C. The calculated RMS value can be converted directly into phasor form
- D. RMS is measured for both sinusoidal and non-sinusoidal signals
- E8A06 (A)
What is the approximate ratio of PEP-to-average power in an unprocessed single-sideband phone signal? #card
- A. 2.5 to 1
- B. 25 to 1
- C. 1 to 1
- D. 13 to 1
- E8A07 (B)
What determines the PEP-to-average power ratio of an unprocessed single-sideband phone signal? #card
- A. The frequency of the modulating signal
- B. Speech characteristics
- C. The degree of carrier suppression
- D. Amplifier gain
- E8A08 (C)
Why are direct or flash conversion analog-to-digital converters used for a software defined radio? #card
- A. Very low power consumption decreases frequency drift
- B. Immunity to out-of-sequence coding reduces spurious responses
- C. Very high speed allows digitizing high frequencies
- D. All these choices are correct
- E8A09 (D)
How many different input levels can be encoded by an analog-to-digital converter with 8-bit resolution? #card
- A. 8
- B. 8 multiplied by the gain of the input amplifier
- C. 256 divided by the gain of the input amplifier
- D. 256
- E8A10 (C)
What is the purpose of a low-pass filter used at the output of a digital-to-analog converter? #card
- A. Lower the input bandwidth to increase the effective resolution
- B. Improve accuracy by removing out-of-sequence codes from the input
- C. Remove spurious sampling artifacts from the output signal
- D. All these choices are correct
- E8A11 (A)
Which of the following is a measure of the quality of an analog-to-digital converter? #card
- A. Total harmonic distortion
- B. Peak envelope power
- C. Reciprocal mixing
- D. Power factor
