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DFRT-PFM Workshop

27.11.2014

Earlier in November 2014, Zurich Instruments participated in a 2-day workshop on Piezoresponse Force Microscopy (PFM) organized by the Institut des Nanotechnologies de Lyon (INL) and the CNRS network RéMiSoL (Réseau des Microscopies à Sondes Locales). Starting with some theoretical introduction by Prof Brice Gautier, 2 parallel sessions on practical...

Demodulating Down to DC with the HF2LI

18.11.2014

DC Demod

Many of our customers use the possibility to measure DC voltage and current, together with an ac signal by setting the demodulation frequency ω=0. The measured value is seemingly incorrect as you need to divide the obtained rms value with the factor of √2 to get the actual signal amplitude...

Basic Vector Network Analyzer Measurements with the UHFLI

03.07.2014

Reflection

Introduction This blog post describes how to measure reflection and transmission coefficients using the Zurich Instruments UHFLI Lock-in Amplifier and a directional coupler. Network analysis is commonly performed in radiofrequency (RF) measurements. A network analyzer is an instrument that measures the network parameters of electrical circuits. Circuits that can be...

How to Achieve More Stable Z-feedback in FM-AFM Mode

15.05.2014

Choice of set point

The challenge with FM-AFM mode (or NC-AFM) is that tip-sample interaction can be either attractive (negative frequency shift, -df) or repulsive (positive frequency shift, +df) which leads to different parameter settings for the Z feedback loop with, respectively, either a positive or negative slope. For atomically smooth surfaces this is...

Sideband Analysis with Lock-in Amplifiers

27.02.2014

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 (such as the HF2LI and the UHFLI) can measure up to 8 frequencies simultaneously and...

Reducing Ground Disturbances with the HF2TA

26.02.2014

Ground Test Setup

Ground loops can pose a serious problem in many measurement setups. Due to the multiple connections to and from the HF2TA Current Amplifier and other external components, several ground loop related issues can pop up in the signal being measured. These issues can be high-frequency oscillations (> 10 MHz), 50/60...

High-Speed AFM Measurements

19.02.2014

Typically, for biological and catalysis applications time matters - and AFM images recorded in 10 minutes or longer are not acceptable. We often receive inquiries about what constitutes a complete solution for 'fast AFM' and what Zurich Instruments can offer in this area. Therefore, I would like to describe here...

Ring-Down Method for Rapid Determination of High Q-Factor Resonators

18.12.2013

Ring down

With the miniaturization of circuits and components such as MEMS and now also NEMS, the variety and quality of macro-fabricated devices have dramatically increased, leading to packaged or embedded systems with particularly sensitive electromechanical properties. The basic properties, such as resonance frequencies, Q-factor and dissipative power requires more and more...

GHz Differential Amplifier Using a 180° 2-Way Power Splitter

10.10.2013

Splitter Input/Output

Every now and then, a differential amplifier in the frequency range of the UHFLI Lock-in Amplifier is needed. The requirements for such an amplifier are low noise and a frequency range of at least 600 MHz. A commercial solution with an active differential amplifier is not available today. A straightforward...

How to Tune the HF2LI-PID Controllers

17.09.2013

Step Response

I often get questions from first-time users on how to properly tune the PID gain parameters. I am no expert in feedback control systems or the PID loop optimization, but I do believe tuning the HF2LI-PID parameters should not be an intimidating task for anybody who needs to use the...

Double-Sideband Suppressed-Carrier Modulation

28.08.2013

Double-sideband suppressed-carrier (DSB-SC) modulation is an amplitude modulation that consists only of the two symmetrical sidebands and no carrier band. I came across this scheme in an ultrasound application, where power utilization can be maximized when all power is available on the sidebands. It turns out that DSB-SC modulation can...

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