Company Blog

Detecting a Small Fraction of Impedance Changes with Improved Sensitivity

16.09.2014

Basic Vector Network Analyzer Measurements with the UHFLI

03.07.2014

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

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 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...

Taking Your Microfluidics EIS Measurement to the Ultra-High Frequency Domain

08.01.2014

Introduction The HF2IS Impedance Spectroscope from Zurich Instruments is a versatile tool suitable for label-free electrical impedance spectroscopy (EIS) of single cells in the domain of cell counting and discrimination. The high frequency range, from DC to 50 MHz, and the multi-frequency capability of the instrument enable microfluidics researchers not...

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

18.12.2013

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

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

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...

Using a 10 MHz Clock Reference with HF2 Instruments

27.05.2013

Phase-synchronous operation of a variety of frequency sources and analyzers is a common requirement, which is usually solved by distributing a 10 MHz clock signal to which the individual instruments are phase-locked. This ensures not only a perfect frequency match between the referenced instruments, but also guarantees a constant phase...

Optimize Your HF2TA Transimpedance Amplifier Settings

24.05.2013

Users of the HF2TA transimpedance amplifier should always be aware of the trade-off between the transimpedance gain and the 3-dB roll-off bandwidth of the amplifier. (Hint: Since the HF2 software release 12.08, the bandwidth is also specified in the HF2TA gain drop-down list in ziControl.) However, there are other pitfalls...

Broadcasting FM and AM Radio with the UHFLI

06.05.2013

Following my previous blog post , people advised me to try to broadcast FM radio too. For this, I had to retreat into Zurich Instruments' shielded radiation lab, so that my experiment would remain concealed. It then took about 5 minutes to broadcast tunes from my mobile phone's 3.5 mm...

Listening to FM Radio with the UHFLI

17.04.2013

Someone at Zurich Instruments soldered a 3.5-mm headphone socket to a BNC cable and attached a 75-cm antenna wire to the Signal Input of the UHFLI Lock-in Amplifier with the UHF-PID PID/PLL option and was happily listening to FM radio. Abuse alert! I instantly had to copy that one.