Posts by Mehdi

How to Retrieve the Carrier Frequency of Phase-Modulated or Carrier-Suppressed Signals with Costas Loops

on 08.11.2020 at 13:43 by Mehdi on Blog of Mehdi Alem
Introduction  Phase-locked loops (PLLs) are widely used to recover the frequency of a carrier signal in many detection systems such as lock-in amplifiers and data receivers. In order to properly lock to the carrier phase and extract its frequency, a […]

How to Generate QAM Signaling with the HDAWG Arbitrary Waveform Generator

on 25.11.2019 at 12:24 by Mehdi on Blog of Mehdi Alem
Introduction  Digital modulation is extensively used in telecommunications, radar systems and quantum technologies. Corresponding to every analog modulation technique, i.e. amplitude modulation (AM), phase modulation (PM) and frequency modulation (FM), there is a digital version of signal modulation: amplitude-shift keying […]

Synchronization of Multiple MFLI Lock-in Amplifiers by MDS

on 16.09.2019 at 00:00 by Mehdi on Blog of Mehdi Alem
Introduction  Multi-channel signal generation and detection are indispensable in many applications such as multi-qubit quantum computing and multi-sensor systems. Synchronization of signal channels comes to the equation when the temporal sequence of events is of interest, especially for fast physical […]

Frequency-Domain Response of Lock-in Filters

on 19.03.2019 at 18:10 by Mehdi on Blog of Mehdi Alem
Introduction  The response of a lock-in amplifier is characterized by the parameters of its low-pass filter (LPF), i.e. time constant and filter order. The temporal response of the LPF demonstrates the latency of measurement while its spectral response shows the […]

How to Demodulate Multi-frequency Signals such as AM, FM and PM

on 20.03.2018 at 13:26 by Mehdi on Blog of Mehdi Alem
Introduction  When analyzing signals with multiple frequency components, it is important to measure the amplitude and phase of each frequency component accurately so that a change in the characteristics of one component does not affect the measurement of another frequency component. There […]

Generation of Single-Sideband Modulation by Arbitrary Waveform Generators

on 15.12.2017 at 17:32 by Mehdi on Blog of Mehdi Alem
Introduction  I/Q modulations are extensively used in a variety of applications including telecommunications, quantum computing (QC), nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR) spectroscopy and band-excitation atomic force microscopy (AFM). In this post, we demonstrate how to generate such signals using Arbitrary […]

Enhancing the Luminosity Quality of Sulfur Plasma Lamps by the HF2PLL Phase-Locked Loop

on 07.12.2017 at 14:11 by Mehdi on Blog of Mehdi Alem
Introduction The choice of technology in lighting industry requires a trade-off between color rendering and luminous efficacy because the spectral sensitivity of the human eye varies with wavelength. As sustainable development has become a priority, the manufacturing industry of lighting […]

Kramers–Kronig Test Applied to Impedance Measurements of Electrical Circuits

on 25.09.2017 at 06:57 by Mehdi on Blog of Mehdi Alem
Introduction  In this post, the Kramers-Kronig relations are used to verify the results of an impedance measurement experiment performed by the Zurich Instruments MFIA Impedance Analyzer or MFLI Lock-in Amplifier equipped with the MF-IA option. The Kramers-Kronig relations state that the real […]

Noise Analysis of Signal Components

on 29.03.2017 at 13:57 by Mehdi on Blog of Mehdi Alem
Introduction  In this post, the relation between the noise of signal amplitude and phase on one hand and the noise of in-phase and quadrature components of the signal on the other hand is investigated. We try to respond to the wrong […]

Time-Domain Response of Lock-in Filters

on 09.02.2017 at 08:36 by Mehdi on Blog of Mehdi Alem
Introduction  The heart of a lock-in amplifier is a phase-sensitive detector which includes a signal mixer and a low-pass filter. In this post, we focus on the time response of the low-pass filters implemented in Zurich Instruments lock-in amplifiers including […]

The Nyquist Diagram for Electrical Circuits

on 11.01.2017 at 07:10 by Mehdi on Blog of Mehdi Alem
Introduction The Nyquist diagram of a transfer function is a parametric plot of its imaginary part versus real part as the frequency sweeps in a certain range [1]. When dealing with electric circuits, the transfer function is the immittance [2] of the […]

Categories