Publications by Pavel Kejik | EPFL Graph Search

The High-Resolution Magnetic Camera: A Novel Sensor for Eddy Current Testing

Roland Moser, Hannes Bleuler, Marco Picasso, Pavel Kejik, Gilles Raphaël Santi, David Florian Hippert

Eddy current techniques are often used to detect and, in some advanced applications, to characterize fatigue surface-breaking cracks appearing in mechanical parts. One of the major difficulties in this approach is to reliably separate the crack contributio ...

Ios Press2014

Characterization of Surface Cracks Through The Local Magnetic Field Induced by Eddy Currents

Roland Moser, Hannes Bleuler, Marco Picasso, Pavel Kejik, Gilles Raphaël Santi, David Florian Hippert

It is important to reliably characterize cracks in metallic mechanical parts in order to assess the serenity of damage due to fatigue. The most important parameter for this is the crack depth. This is notoriously difficult with standard Eddy current techni ...

Ios Press2014

Offset Compensation Based on Distributed Hall Cell Architecture

Pavel Kejik, Pierre-André Farine, Pierre-François Thibault Bourdelle

A new offset reduction strategy for CMOS Hall devices is proposed. The novelty is to fragment the Hall device into multiple Hall blocks, distributed over the silicon area and easy to interconnect. The suitable number of Hall blocks and the bias current lev ...

Institute of Electrical and Electronics Engineers2013

Layout and Architecture Issues in Hall based CMOS microsystems

Pavel Kejik, Pierre-André Farine

The Hall cells intended for industrial applications are mainly produced in silicon integrated circuit technology. Recently, the increased use of other technologies, such as GaAs, InAs and InSb, have been reported. However, a single chip solution comprising ...

Czech Technical University in Prague, Faculty of Electrical Engineering2012

An Integrated Probe for Electromagnetic NDT Inspection

Pavel Kejik

Electromagnetic techniques present definite advantages for Non Destructive Testing such as no need for surface couplant, potential for miniaturization, and fast scanning rates. They suffer, however, from a lack of reliability when crack sizing capabilities ...

2010

Offset compensation based on distributed Hall system architecture

Radivoje Popovic, Pavel Kejik

Integrated Hall devices have the great advantage, over other magnetic sensors, that they can be fully fabricated by a standard CMOS process. However they are known to have a relatively large offset (i.e. residual voltage at zero magnetic field). Techniques ...

2010

Hall sensor array

Pavel Kejik

Integrated circuit Hall sensor system comprising a plurality of elementary blocks (EB), each elementary block including a Hall cell (4), a differential pair (8) of an input stage of a Differential Difference Amplifier (DDA), and terminals (12a, 12b), where ...

2010

Ultra Low-Power Angular Position Sensor for High-Speed Portable Applications

Radivoje Popovic, Pavel Kejik

We present a technique for contactless angular position sensing that allows low power consumption while keeping dynamic properties comparable to existing sensors. The technique essentially consists in combining a recently developed sensing element, the so- ...

IEEE Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2009

Orthogonal fluxgate magnetic field sensor

Pavel Kejik, Ozge Zorlu

Orthogonal fluxgate sensor for measuring an external magnetic field Hext, comprising a conductor for carrying an excitation current lexc, a ferromagnetic material adapted to saturate in the presence of a magnetic field generated by the excitation current, ...

2009

Micro Fluxgate Sensor with Cascaded Planar Ring Cores

Pavel Kejik, Ozge Zorlu

In this paper, we present a new microfabricated fluxgate sensor structure having cascaded planar rings as the ferromagnetic core. A circular magnetic excitation is provided with a rod passing through the FeNi rings as a sewing thread. Planar coils placed u ...

2009

Integrated Magnetic Angle Sensors

Radivoje Popovic, Pavel Kejik, Mirjana Banjevic

2008

Purely CMOS Angular Position Sensor Based on a New Hall Microchip

Radivoje Popovic, Pavel Kejik

This paper presents a new technique to sense the direction of the magnetic field, enabling a new generation of contactless 360 degrees absolute angle encoders. The sensor consists of a microchip that contains a special ring-shaped Hall element. It is the f ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2008

Magnetic field sensor for measuring direction of a magnetic field in a plane

Radivoje Popovic, Pavel Kejik

A magnetic field sensor for measuring a direction of a magnetic field in a plane comprises a sensing structure (4) comprising a ring-shaped well (10), a plurality of contacts (11) of equal size placed at equal distance from each other along the ring-shaped ...

2008

An orthogonal fluxgate-type magnetic microsensor with electroplated Permalloy core

Radivoje Popovic, Pavel Kejik, Ozge Zorlu

In this paper, we present a new microfabricated orthogonal fluxgate sensor tructure. The sensor consists of an electroplated copper excitation rod surrounded by an electroplated Permalloy layer and has planar pick-up coils for signal detection. The use of ...

Elsevier2007

Three-Axis Teslameter with Integrated Hall Probe

Radivoje Popovic, Pavel Kejik, Enrico Schurig

The first commercially available teslameter with a fully integrated three-axis Hall probe is described. The Hall probe chip contains horizontal and vertical Hall elements, analog electronics, and a synchronization circuit. A horizontal Hall element measure ...

Institute of Electrical and Electronics Engineers2007

Fluxgate-type magnetic microsensors for wide linear measuring range

Radivoje Popovic, Pavel Kejik, Ozge Zorlu

In this paper, we present a microfabricated fluxgate sensor for wide linear measuring range applications. The sensor consists of an electroplated copper excitation rod surrounded by an electroplated Permalloy core layer, and has planar pick-up coils for si ...

2007

True 2D CMOS integrated Hall sensor

Radivoje Popovic, Pavel Kejik

We have designed and realized a new integrated Hall structure that converts the magnetic field vector in the chip plane, into an ac signal, whose amplitude and phase correspond to the magnitude and direction of the field, respectively. It is the first Hall ...

2007

Multi-axis integrated Hall magnetic sensors

Radivoje Popovic, Pavel Kejik

2007

Integrated Hall Microsystem with Current Re-Use

Radivoje Popovic, Pavel Kejik, Predrag Drljaca

A new architecture of a Hall microsystem for low-power applications is presented. The innovation in this paper lies in the re-use of the electric current for biasing of several parts in the microsystem permitting substantial reduction of the current consum ...

American Scientific Publishers2007

Circular Hall transducer for angular position sensing

Radivoje Popovic, Pavel Kejik

We developed a new integrated magnetic sensor based on the Hall effect, suitable for the application in magnetic contactless 360° absolute angle sensors. The device consists of a narrow n-well ring with a chain of 64 contacts equally distributed around the ...

2007