Answer to Question #108525 in Electric Circuits for Pkm

Question

State with reasons whether the following statements are True or False.i) Bandwidth of frequency modulated (FM) signal is narrower than that of amplitude modulated (AM) signal.
ii) Amplitude shift keying is modulation of digital carrier by analog signal.
iii) GSM is a spread spectrum technology.
iv) TRF receivers are preferred over super-heterodyne receivers in audio communication.
v) Schottky diode can handle higher frequency signals than p-n junction diode.

Answer 1

i) False because AM methods are designed to have more stations available in any frequency range.

ii) False because by definition, "the amplitude of analog carrier signal is modified to carry digital signal".

iii) False because GSM implies using TDMA and FDMA, while spread-spectrum technology does not woth with TDMA and FDMA

iv) False because out of its simplicity, a TRF receiver cannot amplify a specific signal, it amplifies a raw signal and then removes the carries signal, while superheterodyne receiver amplifies the raw signal and mixes it with an internal signal, which among other benefits improves selectivity and sensitivity.

v) True because the diodes in Schottky diodes can operate at higher speeds.