Posts in Category Modulation

Sideband Analysis with Lock-in Amplifiers

on 27.02.2014 at 20:10 by Sadik on Blog of Sadik Hafizovic
When a sinusoidal waveform is periodically modulated in either amplitude or frequency sidebands are generated as a result of this carrier modulation. These sidebands can be measured using a lock-in amplifier. Zurich Instruments lock-in amplifiers (HF2LI and UHFLI) can measure […]

Double-sideband Suppressed-carrier Modulation

on 28.08.2013 at 11:17 by Sadik on Blog of Sadik Hafizovic
Double-sideband Suppressed-carrier (DSB-SC) modulation is an amplitude modulation, which consists only of the two symmetrical sidebands and no carrier band. I came across this scheme in an ultra-sound application, where the power utilization can be maximized when all power is […]

Broadcasting FM and AM Radio with the Zurich Instruments UHFLI 600 MHz Lock-in Amplifier

on 06.05.2013 at 17:19 by Sadik on Blog of Sadik Hafizovic
Following my previous blog, Listening to FM Radio with the UHFLI 600 MHz Lock-in Amplifier and PLL, people advised me to also try and broadcast FM Radio. Naturally for this I had to retreat into Zurich Instruments’ shielded radiation lab, […]

Listening to FM Radio with the UHFLI 600 MHz Lock-in Amplifier and PLL

on 17.04.2013 at 11:10 by Sadik on Blog of Sadik Hafizovic
A guy at Zurich Instruments soldered a 3.5mm headphone socket to a BNC cable and attached a 75-cm antenna wire to the Signal Input of our 600MHz UHFLI Lock-in Amplifier with UHF-PID PID/PLL option and was happily listening to FM […]

Amplitude and Frequency/Phase Modulation Explained

on 20.10.2011 at 09:22 by Michele Zaffalon on Blog of Michele Zaffalon
I always had difficulties in understanding frequency modulation (FM) and its frequency spectrum. Even for the pure tone modulation, the FM spectrum consists of an infinite number of sidebands whose signs change from one sideband to the next one and whose amplitudes are given by the horrible Bessel functions. I have a pictorial representation of AM/FM that helped me understand the sidebands.

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