Igor Vehec

Design of microstrip band pass filter based on LTCC for UWB sensor system

This paper deals with design, simulation, manufacturing and experimental testing of microstrip bend pass (BP) filter for I - Q (In-phase Quadrature) demodulator that is a part of Ultra Wide-Band (UWB) sensor system. Paper refers to the needs that should be focused on the design and manufacturing of microstrip filters based on LTCC (Low Temperature Co-fired Ceramic) with emphasis on issues of quality of transmitted signals in the high frequency (HF) area in the terms of actual production. There are presented simulated and measured results of insertion loss (S21) and return loss (S11) of microstrip BP filter for I - Q demodulator made from material system Green Tape 951 XP. This paper demonstrates the design and full-wave electromagnetic simulation of microstrip BP filter using the HyperLynx 3D EM Designer (from Mentor Graphics). It assesses the suitability of LTCC material system Green Tape 951 XP as well as conductor paste DuPont 6145 for the production of microstrip BP filters for HF area. The presented filters should be used as a BP filter mean for I - Q demodulator presented in [1] which is a part of laboratory UWB sensor system.

Technology and Application of 3D Shaped LTCC Modules for Pressure Sensors and Microsystems

This paper deals with shaping technology of LTCC (low temperature cofired ceramics) and as well on analysis of the possibilities of sensors in 3D shaped modules. Analysis of marginal possibilities of LTCC ceramic shaping was realized on a sample with various bending angles and various layer numbers, where thick-film conductive paths were present. The applicability of the obtained results was demonstrated by the development of a 3D shaped module with a thick-film pressure sensor.

Influence of various multilayer LTCC systems on dielectric properties’ stability in GHz frequency range

Purpose The purpose of this paper is to create multilayer substrate (composite) from various low temperature co-fired ceramic (LTCC) substrates by their mutual combinations and to analyse influence of these multilayer substrates on dielectric properties in GHz frequency range. Design/methodology/approach GreenTape 951, GreenTape 9K7 and Murata LFC were used to create compound multilayer substrates that include three layers: middle layer is from Murata LFC, and both upper and bottom layers are either from GreenTape 951 or GreenTape 9K7. Shrinkage in all x-, y- and z-axes of all substrates including multilayer substrates were analysed, and influence of different shrinkage on dielectric properties was examined by microstrip ring resonators applied on all mentioned of substrates. Findings The middle layer of Murata LFC has significant influence on shrinkage value of composites which has a good repeatability and minimalizes problems with design of multilayer LTCC devices. Impact of middle layer from Murata LFC on dielectric constant is not significant, but on the other hand Q factor (loss tangent) of these composites is increased according to inhomogeneity between single LTCC layers, especially at frequency around 6 GHz. Originality/value The novelty of this work lies in creating multilayers systems from different types of LTCC substrates to find combination with the most suitable physical and dielectric properties for various purposes in GHz range applications.

Impact analysis of LTCC materials on microstrip filters’ behaviour up to 13 GHz

Purpose – The purpose of this paper is to consider the adequacy of various microstrip filters’ behaviour based on different low-temperature co-fired ceramic (LTCC) dielectrics in the high frequency (HF) area up to 13 GHz. Design/methodology/approach – Low pass, band pass and band stop filters for ultra-wideband radar systems were designed, simulated, fabricated and measured using three various dielectric substrates: Dupont GreenTape 951, Dupont GreenTape 9K7 and Murata LFC. Findings – It is not possible to unambiguously determine the most suitable LTCC dielectric for these filter design because, in general, all designed filters fulfilled requirements (attenuation, cut off frequencies) with minimal divergences, but temperature-stable dielectric and physical properties of Murata LFC make them a promising ceramic for HF application (repeatability of realised experiments). Originality/value – The novelty of this work lies in unconventional usage of LTCC as material with defined dielectric properties proper fo...

Influence of firing profile on microstructural and dielectric properties of LTCC substrates

Purpose The purpose of this paper is to analyse the influence of various firing profiles on microstructural and dielectric properties of low-temperature, co-fired ceramic (LTCC) substrates in a GHz frequency range. According these analyses, sintering process can be controlled and modified to achieve better performance of devices fabricated from LTCC substrates. Design/methodology/approach Samples from LTCC substrates GreenTape 951 and GreenTape 9K7 were sintered by four firing profiles. Basic firing profile recommended by the manufacturer was modified by increasing the peak temperature or the dwell time at the peak temperature. The influence of firing profile on microstructural properties was analysed according to measurements by X-ray diffractometer (application of the Cu K-alpha radiation and the Bragg-Brentano method), and the influence on dielectric properties (dielectric constant and dielectric losses) was analysed according to measurements by split cylinder resonator method at 9.7 and 12.5 GHz. Findings Rising of the peak temperature or extension of dwell time at this temperature has influence on all analysed properties of LTCC substrates. Size of crystallites can be changed by modification of firing profile as well as microdeformation. In addition, dielectric properties can be changed too by modification of the firing profile. Correlation between microdeformation and dielectric losses was observed. Originality/value The novelty of this work lies in finding the mutual relationship between changes in microstructural (size of grains and microdeformation) and dielectric properties (dielectric constant and dielectric losses) caused by different firing profiles.

Design of low pass filter for UWB application

This paper deals with design, simulation and experimental testing of a low pass (LP) filter for Ultra Wide-Band (UWB) radar applications. The paper focuses on various technological possibilities of production that are used in the branch of UWB filters. This paper demonstrates the design of LP filter realised by the Filter Solution 2011 from Nuhertz as well its simulation done by Ansoft Designer from ANSYS. Simulated and measured results of insertion loss and return loss response of LP filter for UWB radar are presented. This paper assesses the suitability of hydrocarbon ceramic laminate substrate for the production of LP filter for high frequency (HF) area. Paper refers to the needs to be focused on the design of passive filters used in UWB radar systems with emphasis on issues of quality of transmitted signals in the HF range. It examines potential manufacturing possibility of such filter based on Low Temperature Ceramics (LTCC) technology too. The presented filter is an example of an antialiasing LP filter for particular laboratory UWB radar.

Animated components in the scope of the electronic technologies education

The contribution deals with possibilities and practical utilization of animated components in educational process with the scope of technologies used in microelectronic industry. The effort in this area is the part of evolvement of multimedia support in education process at the Department of Technologies in Electronics of Technical University of Košice. With utilization of multimedia components were created number of study modules for electronic educational courses in the area of materials, technologies and sensors used in electronics industry.

E-learning system and virtual laboratory for the study of electronic technologies

The paper describes the e-learning system and virtual laboratory that are intended for implementation into electrotechnology-oriented study programs. It is a short description of the main functions of the systems as well as the technologies used for the implementation.

Chosen electrical and reliability properties of thick film photoimageable components

This paper presents the correlation between electrical and reliability properties and processing conditions. Fodelreg photoimageable technology as an extension of traditional thick-film process providing a higher line resolution, has been considered in the field of unconventional application based on both 3D bent multilayers and thick film mono and multilayer inductors construction with a resolution about 150 mum. Common denominator of two different ideas is our experience with thick film photoimageable conductors and study of chosen electrical and reliability properties. The developed and adapted LTCC technology based on photoimageable technology has produced about 100 mum wide lines that are composed in shaped 3D bent multilayer structures. Chosen electrical properties of inductors based on photoimageable conductor has been evaluated including their ageing reliability test

Stability of miniaturized non-trimmed thick- and thin-film resistors

Abstract This paper is focused on reliability tests of non-trimmed miniaturized thin-film and thick-film resistors. Thick-film resistors are screen printed by polymer paste on LTCC (Low Temperature Co-fired Ceramic) substrate by two different approaches. Nonstandard precise screen printing process provide tolerance of resistivity less than 5% and thus further trimming is not necessary. OhmegaPly material with Nickel Phosphorous (NiP) metal alloy is used for thin-film resistors fabricated by subtractive process. Miniaturized resistors have dimensions 0.5 × 0.5 mm, and thus 1 square, with thickness 1 μm for thin-film and 20 μm for thick-film resistors. Stability of miniaturized resistors were tested by humidity test, thermal shocks, long-term thermal ageing, direct current stress, current pulses and simulation of soldering process using VPS (Vapour Phase Soldering). Resistivity of resistors is measured by four wire method before and after each set of test and relative change of resistivity is plotted in graphs. Influence of every test on each type of resistor is analysed.