- Type of paper
: Book
Title: Mixing, Mixers and Frequency Synthesizers
- Authors:
- Modlic, Borivoj
- Bartolić, Juraj (2316)
- Editors
- Matutinović, Želimir
Publisher: Školska knjiga
ISBN: 953-0-30651-1
Year: 1995
Number of pages: 412
Number of references: 788
Language: hrvatski
- Type of paper
: Paper in book
Title: Telecommunications, Radiocommunications
- Authors:
- Zentner, Ervin (54750)
- Editors
- Požar, Hrvoje
Publisher: Leksikografski zavod "Miroslav Krleža"
ISBN: 86-7053-026-0
Year: 1992
Pages: from 576 to 613
Number of references: 21
Language: hrvatski
- Type of paper
: Paper in book
Title: Impedance Transformers
- Authors:
- Zentner, Ervin (54750)
Publisher: Leksikografski zavod "Miroslav Krleža"
Year: 1995
Language: hrvatski
- Type of paper
: Paper in journal
Title: Some Aspects of Microwave Diode Mixer Simulation
- Authors:
- Bartolić, Juraj (2316)
Journal: ELEKTROTEHNIKA
Number: 4
ISSN: 0013-5844
Volume: 35
Year: 1992
Pages: from 179 to 186
Number of references: 9
Language: hrvatski
Summary: A numerical method for the Schottky diode microwave mixer
simulation is described. The method is based on the subdivision of the
network into linear and nonlinear parts. The voltage and current waveforms
are determinated by the use of the harmonic balance technique and the
reflection algorithm. Computing is provided in the time and frequency
domains. The fast Fourier transform algorithm is used to convert between
the frequency and time domain. Some examples of diode mixer simulation for
different loading environments are given.
Keywords: Diode mixer, Microwave mixer, Computer application, Simulation
- Type of paper
: Paper in journal
Title: Some Solutions for Increaseing Electromagnetic
Compatibility in the Railways in the Context of the European Community New
Standards on EMC
- Authors:
- Mišljenović, Branko (69655)
- Šimić, Jandro (46784)
Journal: ELEKTROTEHNIKA
Number: 3
ISSN: 0013-5844
Volume: 36
Year: 1992
Pages: from 131 to 135
Number of references: 3
Language: hrvatski
Summary: The paper considers the question of electromagnetic
compatibility in the railways in condition of simultaneous operation of a
great number of electrical systems and facilities and of high requirements
imposed for a safe and reliable operation of them.In the context of the
European Community new standards on electromagnetic compatibility some
actual solutions for sensibility reduction of these facilities influenced
by electromagnetic sources, have been considered.
Keywords: Electromagnetic compatibility, European community (EC), New EC standards, Solutions, Sensibility reduction, Railways
- Type of paper
: Paper in journal
Title: Intermodulation Interference Probability Distribution in
Mobile Radiocommunication Systems
- Authors:
- Zentner, Ervin (54750)
- Bartolić, Juraj (2316)
Journal: ELECTRONICS LETTERS
Number: 3
ISSN: 0013-5194
Volume: 29
Year: 1993
Pages: from 252 to 253
Number of references: 5
Language: engleski
Summary: The problem of mobile radio system outage in the presence
of two signal third order intermodulation interferences is presented. The
probability that the desired signal level exceeds the interference level by
a predetermined value is defined, computed and graphically illustrated. For
all signals the superposition of lognormal and Rayleigh distributions is
assumed.
Keywords: Electromagnetic compatibility, Mobile radio systems, Nonlinear networks, Interference
- Type of paper
: Paper in journal
Title: Conversion Matrix Analysis of Microwave Diode Mixers
- Authors:
- Bartolić, Juraj (2316)
Journal: AUTOMATIKA
Number: 3-4
ISSN: 0005-1144
Volume: 34
Year: 1993
Pages: from 121 to 125
Number of references: 4
Language: engleski
Summary: An efficient and sufficiently gemeral method of microwave
mixer analysis is presented. The process involves first analyzing the
nonlinear device under large-signal excitation only. By the use of
nonlinear anaysis the LO voltage waveform is obtained, and diode
differential conductance and capacitance are determined. A linear diode
model, and conversion admittance are formed which relate the small-signal
sideband currents and voltages of the diode. The expressions for conversion
loss and port impedance are determined. A computer program is developed to
perform the analysis. Resulta are presented to show how the reactive
terminating impedances at image and sum frequency ports affect the mixer
input and output impedances, and mixer concersion loss.
Keywords: diode mixer, microwave mixer, nonlinear analysis, frequency conversion, computer application, simulation
- Type of paper
: Paper in journal
Title: Intermodulation Distortion Estimation of Small Signal
Amplifiers
- Authors:
- Nađ, Robert (33010)
Journal: AUTOMATIKA
Number: 3-4
ISSN: 0005-1144
Volume: 34
Year: 1993
Pages: from 127 to 130
Number of references: 4
Language: hrvatski
Summary: Bipolar transistor CAD modelling is performed. As a basis
the model elements obtained from S parameter measurement and aditional DC
measurements are used. The small signal model is extended to nonlinear
incremental model. A wideband feedback amplifier is designed. The output
spectrum of the realized circuit with the low excitation level is measured.
A nonlinear amplifier transfer function for weak nonlinearities is obtained
by the use of Volterra series representation. The results obtained by
measurements and simulation are compared.
Keywords: Bipolar Junction Transistor Model, Intermodulation Distortion, Nonlinear Incremental Model, Small Signal Amplifier, Volterra series, Weak Nonlinearity
- Type of paper
: Paper in journal
Title: Small Signal RF Amplifier Distortion Analysis Using
Volterra Series Representation
- Authors:
- Nađ, Robert (33010)
Journal: AUTOMATIKA
Number: 1-2
ISSN: 0005-1144
Volume: 35
Year: 1994
Pages: from 3 to 10
Number of references: 8
Language: hrvatski
Summary: Second and third order intermodulation distortion small
signal amplifier using Volterra series is analyzed. Functional series in
high frequency amplifiers with memory are used. Incremantal nonlinear model
is necessary for nonlinear transfer funstion evaluation. Bipolar transistor
model on the basis of S-parameter measurements is performed. It is possible
to obtain second and third intermodulation distortion components in
dependence of the source and load impedance. Optimal source and load
impedances for maximum values of second and third order intercept points
are found.
Keywords: Small Signal Amplifier, Weak Nonlinearity, Intermodulation Distortion, Volterra series, Nonlinear Incremental model
- Type of paper
: Paper in journal
Title: Intermodulation Products Statistics for Various Signal
Models of Their components
- Authors:
- Zentner, Ervin (54750)
Journal: AUTOMATIKA
Number: 3-4
ISSN: 0005-1144
Volume: 35
Year: 1994
Pages: from 73 to 77
Number of references: 5
Language: hrvatski
Summary: Based on the componenet signal statistics with Rayleigh,
lognormal or combined distribution function, a general expression for the
distribution function of n-th order intermodulation products is set up. For
suposed distributions of component signals third order intermodulation
product statistic are determined and for some examples numericaly and
graphicaly represented.
Keywords: Electromagnetic compatibility, nonlinear networks, interfrence, mobile radio systems
- Type of paper
: Paper in proceedings
Title: Electromagnetic Compatibility Testing with TEM cells
- Authors:
- Zentner, Ervin (54750)
Proceedings title: 4. Međunarodni simpozij o novim tehnologijama sv.II
Language: hrvatski
Place: Pula
Year: 1993
ISBN/ISSN: ISBN 86-81997
Pages: from 79 to 83
Meeting: 4. Međunarodni simpozij o novim tehnologijama
Held: from 10/25/93 to 10/27/93
Summary: The preference of measurement with TEM cells in relation to
remainder methods are shown, special for radiation interferen cesource
measurements and susceptability testing. Electric andmagnetic field
measurement methods and examples are demonstrated. Measuring methods and
result of impedance and transfer characteristic measurements on a TEM cell
are presented.
Keywords: Electromagnetic compatibility, interference, measurements
- Type of paper
: Paper in proceedings
Title: Electromagnetic Compatibility of Frequency Converters for
Asynchrone Motors
- Authors:
- Šimić, Jandro (46784)
Proceedings title: 4. Međunarodni simpozij o novim tehnologijama sv.I
Language: hrvatski
Place: Pula
Year: 1993
ISBN/ISSN: ISBN 86-81997
Pages: from 185 to 187
Meeting: 4. Međunarodni simpozij o novim tehnologijama
Held: from 10/25/93 to 10/27/93
Summary: The article deals with the testing methods of frequency
convertors for asynchron motors according to the requirements of the
electromagnetic compatibility. Radio interferences and higher harmonics are
particulary discussed. Compliance of products with EMC requirements will be
affixed by mark consisting the letters CE. This is based on the EMC
Directive mandated by the European Community.
Keywords: Electromagnetic compatibility, frequency converters
- Type of paper
: Paper in proceedings
Title: Nonlinear Incremental Model for Bipolar Junction
Transistor
- Authors:
- Nađ, Robert (33010)
Proceedings title: 4. Međunarodni simpozij o novim tehnologijama sv.I
Language: hrvatski
Place: Pula
Year: 1993
ISBN/ISSN: ISBN 86-81997
Pages: from 177 to 180
Meeting: 4. Međunarodni simpozij o novim tehnologijama
Held: from 10/25/93 to 10/27/93
Summary: Bipolar transistor CAD modelling is performed. As a basis,
the model elements obtained from S parameter measurements and additional DC
measurements are used. The small signal model is extended to nonlinear
incremental model. This model is useful for intermodulation analysis under
low excitation conditions.
Keywords: Nonlinear element modeling, intermodulation
- Type of paper
: Paper in proceedings
Title: Modern Methods for Solving Electromagnetic Compatibility
Problems in Radiocommunication Systems
- Authors:
- Zentner, Ervin (54750)
Proceedings title: ZBORNIK RADOVA 38. MEĐUNARODNI SKUP KoREMA sv.1
Language: hrvatski
Place: Zagreb
Year: 1993
ISBN/ISSN: 953-6037-00-9
Pages: from 13 to 17
Meeting: 38. MEĐUNARODNI GODIŠNJI SKUP KoREMA
Held: from 04/26/93 to 04/28/93
Summary: The organisation of radiochannel management is presented.
Described is the general approach to solve EMC problems. The origin and
effects of non-typical interference sources are analyzed. The measurement
with TEM cell in plane wave conditions is discussed.
Keywords: Atypical interfrence sources, TEM cell
- Type of paper
: Paper in proceedings
Title: Intermodulation Distortion Estemation of Small Signal
Amplifiers
- Authors:
- Nađ, Robert (33010)
Proceedings title: ZBORNIK RADOVA 38. MEĐNARODNI GODIŠNJI SKUP KoREMA
Language: hrvatski
Place: Zagreb
Year: 1993
ISBN/ISSN: 953-6037-00-9
Pages: from 38 to 41
Meeting: 38. MEĐUNARODNI GODIŠNJI SKUP KoREMA
Held: from 04/26/93 to 04/28/93
Summary: Bipolar transistor CAD modeling is performed. As a basis
the model of elements obtained from S parameter measurements and additional
DC measurements are used. The small signal model is extended to nonlinear
incremental model. A wideband feedback amplifier is designed. The output
spectrum of the realized circuit with the low excitation level is measured.
A nonlinear amplifier transfer function for weak nonlinearities is obtained
by use of the Volterra series representation. The results obtained by
measurements and simulation are compared.
Keywords: Intermodulation distortion, Nonlinear differential model, Volterra series
- Type of paper
: Paper in proceedings
Title: Conversion Matrix Analysis of Microwave Diode Mixers
- Authors:
- Bartolić, Juraj (2316)
Proceedings title: 38. MEĐUNARODNI GODIŠNJI SKUP KoREMA
Language: hrvatski
Place: Zagreb
Year: 1993
ISBN/ISSN: 953-6037-00-9
Pages: from 47 to 50
Meeting: 38. MEĐUNARODNI GODIŠNJI SKUP KoREMA
Held: from 04/26/93 to 04/28/93
Summary: An efficient and sufficiently general method of microwave
mixer analysis is presented. The process involves first analyzing the
nonlinear device under large-signal excitation only. By the use of
nonlinear analysis the LO voltage waveform is obtained, and diode
differential conductance and capacitance are determinated. A linear diode
model, and conversion admittance are formed which relate the small-signal
sideband currents and voltages of the diode.The expressions for conversion
loss and port impedance are determined. A computer program is developed to
perform the analysis. Results are presented to show how the reactive
terminating impedances at image and sum frequency ports affect the mixer
input and output impedances, and mixer conversion losses.
Keywords: Mixer, Conversion losses, nonlinear element analysis
- Type of paper
: Paper in proceedings
Title: Determing of the Optimal Common Electrode and the Feedback
for the Negative Resistance Oscillator
- Authors:
- Bartolić, Juraj (2316)
- Urh, Zoran
Proceedings title: ZBORNIK RADOVA 38. GODIŠNJI SKUP KoREMA
Language: hrvatski
Place: Zagreb
Year: 1993
ISBN/ISSN: 953-6037-00-9
Pages: from 42 to 46
Meeting: 38. MEĐUNARODNI GODIŠNJI SKUP KoREMA
Held: from 04/26/93 to 04/28/93
Summary: In this article one of the possible methods in the analysis
of the projecting of the oscillators is exposed. The starting point of this
method is the transistor, the three-port element. The following step is
determining of the common electrode stating the transistor on two-point
element, respectively. By adding the feedback the unit develops into
one-port unit of elements, oscillator. Such analysis needs many
calculations with complex numbers. Quiq transformation of S-parameters from
the common-emitter configuration in the common-base or common-collector
configuration is enabled by the usage of the computer. The adding of the
feedback and input and output matching networks is also possible. This
method is used in the construction of the negative resistance oscillators.
The analysis of greater number of transistors results, derives the
conclusions about the optimal common electrode and the feedback for that
type of oscillators.
Keywords: Oscilators, computer simulations
- Type of paper
: Paper in proceedings
Title: New Methods of Measurement Radio Interference from
Electric Traction Systems
- Authors:
- Mišljenović, Branko (69655)
Proceedings title: ZBORNIK RADOVA 38. MEĐUNARODNI GODIŠNJI SKUP KoREMA
Language: hrvatski
Place: Zagreb
Year: 1993
ISBN/ISSN: 953-6037-00-9
Pages: from 155 to 159
Meeting: 38. MEĐUNARODNI GODIŠNJI SKUP KoREMA
Held: from 04/26/93 to 04/28/93
Summary: In the paper are described sources of radio interferences
in the electric traction systems in the railway. New methods for
measurement radio interferences are elaborated, specially the "stacionary
method" and the method "vehicle in movement". Testing procedures are being
classified, parameters of antenna, environment and conditions for competent
measurement are being defined, methods of recording and elaboration obtain
results are described.
Keywords: Radio interference, traction sistems
- Type of paper
: Paper in proceedings
Title: EMC Figure of Merit Estimation for Two Radar Systems
- Authors:
- Zentner, Ervin (54750)
Proceedings title: Zbornik radova 35. Međunarodni simpozij ELMAR Zadar 1993
Language: hrvatski
Place: Zadar
Year: 1993
ISBN/ISSN: ISSN1330-092X
Pages: from 83 to 86
Meeting: 35. Međunarodni simpozij ELMAR
Held: from 09/24/93 to 09/26/93
Summary: As the EMC figure of merit between two radar systems the
intererence probability is introduced. The antenna radiation pattern,
transmitter spectrum, receiver response and signal processing are taken
into consideration. The antennas are located in the far field region. The
coupling between antennas is expressed as a statistical variable.
Keywords: Electromagnetic compatibility of radars, statistics of antenna coupling
- Type of paper
: Paper in proceedings
Title: Nonlinear Distortion Analysis of Feedback Amplifiers Using
Volterra Series Representation
- Authors:
- Nađ, Robert (33010)
- Editors
- Vidmar, Branko
Proceedings title: Zbornik radova 35. Međunarodni simpozij ELMAR
Language: hrvatski
Place: Zadar
Year: 1993
ISBN/ISSN: 1330-092 X
Pages: from 176 to 179
Meeting: 35. Međunarodni simpozij ELMAR
Held: from 09/24/93 to 09/26/93
Summary: In this paper the method of analysis of feedback amplifiers
using Volterra series representation of nonlinear transfer function is
presented. Nonlinear transfer functions are evaluated using exponential
probing method. Special attention was given to the third-order transfer
function analysis. Some methods using feedback for decreasing third-order
distortion are analyzed.
Keywords: Nonlinear distortion, interferences, amplifiers
- Type of paper
: Paper in proceedings
Title: Integration of Mobile Communication Systems in the Railway
by Application of Modern Technology in the Electronics
- Authors:
- Mišljenović, Branko (69655)
Proceedings title: Zbornik referatov, XIII. Jugoslovanski simpozij o elektroniki v prometu
Language: hrvatski
Place: Ljubljana, Slovenija
Year: 1991
Pages: from 149 to 162
Meeting: XIII. Jugoslovanski simpozij o elektroniki v prometu
Held: from 10/01/91 to 10/05/91
Summary: In the conditions of a gradual inclusion of the railways in
the network of the high-speed lines, the requirements are being increased
for higher capacity and quality of the information transmission along the
railway lines and between the centres, lines and trains in movement.
Progress in development of the electronics, particulary in development of
integrated modules, microprocessor and other circuits, makes posible the
integration of communication system functions accompanied by the
significant improvement of the relevant parameters.
Keywords: Railway communication systems, interference, safety
- Type of paper
: Paper in proceedings
Title: Electromagnetic Compatibility of Radio Systems and
Electric Trains
- Authors:
- Zentner, Ervin (54750)
Proceedings title: 3. Međunarodni simpozij o novim tehnologijama sv.5
Language: hrvatski
Place: Zagreb
Year: 1991
ISBN/ISSN: ISBN 86-81997
Pages: from 40 to 40
Meeting: 3. Međunarodni simpozij o novim tehnologijama
Held: from 10/15/91 to 10/17/91
- Type of paper
: Paper in proceedings
Title: Comparism of Three Analysis Techniques for Microwave
Plannar Antennas
- Authors:
- Bartolić, Juraj (2316)
- Miletić, Alenka
- Šipuš, Zvonimir
Proceedings title: 3. Međunarodni simpozij o novim tehnologijama
Language: hrvatski
Place: Zagreb
Year: 1991
ISBN/ISSN: ISBN 86-81997
Pages: from 55 to 59
Meeting: 3. Međunarodni simpozij o novim tehnologijama
Held: from 10/15/91 to 10/17/91
Summary: The paper deals with three different theoretical analysis
techniques including transmission line and multimode cavity models, and
method of moments in which dyadic Green's function is used. Calculations of
input impedance are compared with measured data for realized experimental
models of microstrip patch antennas.
Keywords: Multimode cavity model, method of moments
- Type of paper
: Paper in proceedings
Title: Microstrip Antenna Technology
- Authors:
- Bartolić, Juraj (2316)
- Zentner, Ervin (54750)
- Miletić, Alenka
- Šipuš, Zvonimir
Proceedings title: 3. Međunarodni simpozij o novim tehnologijama
Language: hrvatski
Place: Zagreb
Year: 1991
ISBN/ISSN: ISBN 86-81997
Pages: from 66 to 70
Meeting: 3. Međunarodni simpozij o novim tehnologijama
Held: from 10/15/91 to 10/17/91
Summary: In this paper a comprehensive surway of the state and
perspective of microstrip antenna technology development is provided. The
critical microstrip antenna features for various configurations are
discussed, together with antenna design and modeling techniques of
elementary antennas and antenna arrays.
Keywords: Microstripe technology, modelling
- Type of paper
: Paper in proceedings
Title: Optimum Channel Asignment in Mobile Radio Communication
Systems Considering the Traffic Density
- Authors:
- Zentner, Ervin (54750)
Proceedings title: 3. Međunarodni simpozij o novim tehnologijama
Language: hrvatski
Place: Zagreb
Year: 1991
ISBN/ISSN: 86-81997
Pages: from 75 to 78
Meeting: 3. Međunarodni simpozij o novim tehnologijama
Held: from 10/15/91 to 10/17/91
Summary: The available spectrum assigned to the mobile radio
communication system is limited therefore the requirement to achive the
best possible efficiency is an ultimate goal. With prescribed blocking
probability and cochannel interference the total spectrum efficiency is
investigated for some cell configurations. It is shown how the total
spectrum efficiency depends on the total available number of radio channels
for sectorized and undevided cell configurations. The performed analysis
makes possible to select the total number of channels and cell
configurations to achive maximum spectral efficiency.
Keywords: Radio networks, channel asignment, interference
- Type of paper
: Paper in proceedings
Title: Spectrum Effciency of Mobile Radiotelephone Systems with
Sectorized Cells
- Authors:
- Zentner, Ervin (54750)
Proceedings title: Zbornik 33. Simpozija ETAN u pomorstvu
Language: hrvatski
Place: Zadar
Year: 1991
ISBN/ISSN: ISSN0353-4685
Pages: from 275 to 278
Meeting: 33. Simpozij ETAN u pomorstvu, Zadar 1991
Held: from 06/24/91 to 06/26/91
Summary: Analysed is a mobile radiotelephone system with hexagonal
cells split in 2,3 and 6 sectors. Determined is the total spectrum
efficiency and compared with the efficiency of a system with undivided
cells.
Keywords: Mobile radio communication systems, interferences, efficiency
- Type of paper
: Paper in proceedings
Title: Active Gunn-Patch Elements and Arrays
- Authors:
- Bartolić, Juraj (2316)
- Šipuš, Zvonimir
- Zentner, Ervin (54750)
- Editors
- Vidmar, Branko
Proceedings title: Zbornik 34. Simpozija ELMAR
Language: engleski
Place: Zadar
Year: 1992
ISBN/ISSN: 86-80139-01
Pages: from 144 to 148
Meeting: 34. Simpozij ELMAR Zadar 1992
Held: from 09/28/92 to 09/30/92
Summary: In this paper an active antenna composed of Gunn diode and
rectangular patch is presented. Using quasi-optical combining technique a
simple active array of two Gunn-patch elements was realized. The radiation
patterns, ERP, and power combining and phase locking properties of an
active antenna have been measured. ERP of 96 mW with 25 mW diode at the
frequency of oscillation 11.7 Ghz is obtained. Experiments demonstrate
feasibility of the oscillating antenna concept in trasmitting active
arrays.
- Type of paper
: Paper in proceedings
Title: Probability Distributions of Interferences Caused by
Intermodulation in the Reciver
- Authors:
- Zentner, Ervin (54750)
- Bartolić, Juraj (2316)
Proceedings title: Zbornik 34. Simpozija ELMAR
Language: hrvatski
Place: Zadar
Year: 1992
ISBN/ISSN: 86-80139-01
Pages: from 154 to 157
Meeting: 34. Simpozij ELMAR Zadar 1992
Held: from 09/28/92 to 09/30/92
Summary: The pdf of the third order intermodulation products is
analysed with the assumption that all signals follow the superposition of
the Rayleigh and lognormal distribution. The probability that the recived
signal level exceeds the interference level caused by intermodulation is
computed and graphicaly presented.
Keywords: Intermodulation, statistics of the electromagnetic wave propagation,
- Type of paper
: Paper in proceedings
Title: Prediction of Interaction between Traction and
Telecommunication Electric Circuits
- Authors:
- Šimić, Jandro (46784)
Proceedings title: ZBORNIK RADOVA 37. MEĐUNARODNI GODIŠNJI SKUP KoREMA
Language: hrvatski
Place: Zagreb
Year: 1992
ISBN/ISSN: 86-81571-11-7
Pages: from 591 to 595
Meeting: 35. Međunarodni simpozij ELMAR
Held: from 04/26/92 to 04/29/92
Summary: The paper deals with prediction of interactions of traction
and telecommunication (tk) electric circuits caused by inductive and
capacitive couplings using the transmission line theory with distributed
parameters. For calculations of interferences between mentioned circuits
computer program SIMID was used. This program is developed for cross talk
calculations by tk lines. The accuracy and reliability of input parameters
are discussed as equally as the results of the past interference
measurements.
Keywords: Electromagnetic interfrence, distributed parameters, cross talk
- Type of paper
: Paper in proceedings
Title: Nonlinear Distortion Estimation of Weakly Nonlinear
Systems
- Authors:
- Nađ, Robert (33010)
Proceedings title: Zbornik 34. Simpozija ELMAR
Language: hrvatski
Place: Zadar
Year: 1992
ISBN/ISSN: 86-80139-01
Pages: from 227 to 231
Meeting: 34. Simpozij ELMAR Zadar 1992
Held: from 09/28/92 to 09/30/92
Summary: Nonlinearities in radiocommunication systems signal
processing units cause various signal distortions, which are a great design
problem. Low distortion level becomes more important every day because of
the rising number of frequency components used in thes pecific band.
Advanced technology products in reciver circuits improve low level signal
processing characteristics, but the effects of unwanted signal like
distortions, often cause serious problems.This is why one tries to find a
mathematical model of systems with weak nonlinearities. The model is
described with the nonlinear transfer function that is expressed with
Volterra functional.
Keywords: Nonlinear distortion, Volterra series, intermodulation
- Type of paper
: Paper in proceedings
Title: Effect of RF Load Impedance on Intermodulation Distortion
- Authors:
- Nađ, Robert (33010)
Proceedings title: ZBORNIK RADOVA 39.MEĐUNARODNI GODIŠNJI SKUP KoREMA
Language: hrvatski
Place: Zagreb
Year: 1994
Pages: from 35 to 38
Meeting: 39.MEĐUNARODNI SKUP KoREMA
Held: from 04/25/94 to 04/27/94
Summary: Narrow band RF amplifier was realized with LC coupling
networks. Using nonlinear active element model, narrow band amplifier
parameters were computed. Imtermodulation components for each amplifier
load impedance were calculated using Volterra series. From the results it
is posible to conclude that intermodulation distortions are related to the
load impedance. Some minimization effect could be realized but with some
gain degradation. Also, some interaction between second harmonic load
impedance and total intermodulation distortion was obtained. Theoretical
results of the calculations and analysis were in good agreement with
measurement results.
Keywords: Narrow band amplifier, intermodulation distortion
- Type of paper
: Paper in proceedings
Title: Designing of Wideband Amplifiers with Lossless feedback
- Authors:
- Bartolić, Juraj (2316)
- Polić, Igor
Proceedings title: ZBORNIK RADOVA 40.MEĐUNARODNI GODIŠNJI SKUP KOREMA
Language: engleski
Place: Zagreb
Year: 1995
Pages: from 39 to 42
Meeting: 40.MEĐUNARODNI GODIŠNJI SKUP KoREMA
Held: from 04/19/95 to 04/21/95
Summary: This paper focuses on the class of small signal amplifiers
using a transformer lossless feedback. The feedback is provided with a
ferrite coupler with three or four ports. The frequency bandwith reaches
the lower UHF range ( lower than 1 GHz). Designing of amplifiers by means
of TOUCHSTONE software is presented. The advantage of the use of TOUCHSTONE
software over other similar programs (SPICE,CN/L) has been noted due to the
possibility of making analysis synthesis of the 4-port transformer
(ferrite) couplers. This paper is treating a new amplifier model using a
4-port coupler. It consist of 4 cupled inductances on binocular ferrite
bead. At the and, the feedback loop phase relations are analyzed. It was
found that it was necessery to correct the phase in the collector circuit
in order to achieve the uniform amplification within the whole transmitted
frequency range.
Keywords: Wideband amplifiers, transformator coupling, computer modeling
- Type of paper
: Paper in proceedings
Title: Synthesis of the Low Noise Broadband Amplifier Using
Carlins Method
- Authors:
- Plahutar, Vesna
- Nađ, Robert (33010)
Proceedings title: ZBORNIK RADOVA 40.GODIŠNJI SKUP KoREMA
Language: engleski
Place: Zagreb
Year: 1995
Pages: from 43 to 46
Meeting: 40.MEĐUNARODNI SKUP KOREMA
Held: from 04/19/95 to 04/21/95
Summary: The amplifier synthesis is based on data resulting from
measuring of GaAs MESFET scattering parameters and noise parameters. The
final goal was to achieve the best posible noise factor of the amplifier
with satisfying flat gain response in octave band, using lossless matching
network. The adventage of the Carlins method is that synthesis does not
require transfer function of the matching network, or impedance function of
the load to be previously known. The input matching network will ensure
good noise properties and contribution to the transducer power gain of the
amplifier. If minimum reactance network is considered, using Carlins method
we shall achieve, from graphically chosen initial data, the approximating
rational function pointing to the network topology. The output network was
synthesised using the same method for the gain equalizing purpose.
Keywords: Wideband amplifier, noise factor, matching network
- Type of paper
: Paper in proceedings
Title:
- Authors:
- Zentner, Radovan
- Bartolić, Juraj (2316)
- Zentner, Ervin (54750)
Proceedings title: PROC. OF THE INTERNAT. CONFRRENCE ON ELECTROMAGNETICS FOR ADVANCE APPLICATIONS
Language: engleski
Place: Torino, Italija
Year: 1995
Pages: from 27 to 30
Meeting: International Conference on Electromagnetics for Advanced Applications
Held: from 09/12/95 to 09/15/95
Summary: A procedure of adding a parasitic patch element over a
driven rectangular patch in order to achieve an increased bandwith of
microstrip antennas has been considered. Comprehensive measurements were
carried out and enabled one to determine the influence of a separation
distance between the parasitic and the driven patch on the input impedance
locus. The matchinh network consisting of a single line transformer was
derived and its parameters computed for the antenna with optimized
separation distance between the driven and parasitic patches. The achieved
bandwith is obout 30% with VSWR lower or equal to 2.
Keywords: Parasitic antenna element, matching circuits, line transformer
- Type of paper
: Paper in proceedings
Title:
- Authors:
- Zentner, Ervin (54750)
- Editors
- Vidmar, Branko
Proceedings title: PROCEEDINGS OF THE 37th INTERNATIONAL SYMPOSIUM ELECTRONICS IN MARINE
Language: engleski
Place: Pula
Year: 1995
ISBN/ISSN: 1330-092X
Pages: from 43 to 46
Meeting: 37.Međunarodni simpozij ELMAR
Held: from 09/18/95 to 09/20/95
Summary: In the literature there are well-known sets of
complementary sequences with an unique peculiarity, all sidelobes in the
autocorrelation functions of all members in the set cancel each other by
adding. In the past the complementary codes were separated in frequency,
time or polarization to permit independently processing prior to addition.
This separation can cause decorrelation by radar targets or distributed
clatter, and can prevent cancellation of the sidelobes. In this paper the
simultaneous phase modulation of complementary codes on the same carrier
eliminates this drawback because they are now neither separated in
frequency nor in time, and the cancellation is fulfilled regardless of the
target characteristic or motion.
Keywords: Radars, pulse compression, imterference
- Type of paper
: Paper in proceedings
Title:
- Authors:
- Modlic, Borivoj
- Nađ, Robert (33010)
- Editors
- Vidmar, Branko
Proceedings title: PROCEEDINGS OF THE 37th SYMPOSIUM ELECTRONICS IN MARINE
Language: engleski
Place: Pula
Year: 1995
ISBN/ISSN: 953-96030-1-3
Pages: from 129 to 132
Meeting: 37.Međunarodni simpozij ELMAR
Held: from 09/18/95 to 09/20/95
Summary: The paper gives a review of the basic requirements for the
satisfactory reception quality of VHF-FM sound broadcasting services. The
measuring procedure of electromagnetic field from the local broadcasting
transmitter in Istria as well as the field of interfering signals is
described. The measuring results analysis shows that the RF protection
ratio is not respected at many test locations even where the usable field
level is much higher than the treshold level in reference to standards. The
effect of reduced RF protection ratio on the reception quality are studied
as well.
Keywords: Field measurement, interference signals, RF protection
- Type of paper
: Paper in proceedings
Title:
- Authors:
- Zentner, Radovan
- Bartolić, Juraj (2316)
- Editors
- Vidmar, Branko
Proceedings title: PROCEEDINGS OF THE 37th INTERNATIONAL SYMPOSIUM ELECTRONICS IN MARINE
Language: engleski
Place: Pula
Year: 1995
ISBN/ISSN: 953-96030-1-3
Pages: from 195 to 198
Meeting: 37.Međunarodni simpozij ELMAR
Held: from 09/18/95 to 09/20/95
Summary: A method to finding optimal dimensions of the line
transformer to match an arbitrary load to an arbitrary real impedance is
described. The procedure takes into account the frquency dependance of the
impedance to be matched and optimizes transformer lenght to obtain the
maximum bandwith. It is shown how to find an optimal transformer for a
load, using its prviously measured input impedance data. The restrictions
of such a matching are given. The area in the Smith chart, in which the
load cannot be matched is determined.
Keywords: Matching networks, line transformers
- Type of paper
: Ph.D.
Title: The impact of the passive network of the small signal
semiconductor amplifier on its operating conditions in a given range of
amplitudes and frequencies
Faculty: Fakultet elektrotehnike i računarstva Sveučilište u Zagrebu
Author: NAĐ ROBERT
Date of defense: 10/29/93
Language: hrvatski
Number of pages: 147
Summary: The purpose of the research was the analysis of the
interaction of a semiconductor amplifiers coupling network to the linear
and nonlinear distortion in the circuits for radiocommunication systems.
Analysis was primarily concerned to the systems with weak nonlinearities
using mathematical model with memory ability analysis. The response of
memory systems are depending not only of instantaneous excitation, but
also of excitations which have been existed before this time on the input
of the system as well. This problem, and the problem of general excitation
(excitation function of the general shape including excitation by noise)
was treated by application of Volterra functionals. It has been shown that
such a mathematical approach represent in fact the generalization of the
system impulse response-convolution integral. Because such a mathematical
approach was not usually used in classical intermodulation distortion
analysis in radiocommunication circuits, chapters three and four are
dealing with introduction to Volterra series application in the field of
nonlinear transfer function determination for some particular series.
The starting point in the analysis was the development of linear and
nonlinear models of active element. Measured results of active elements and
of realized circuit was used in the analysis as well. According to the fact
that the analysis was applied in the lower microwave band (below 1 GHz), a
bipolar transistor as active element was chosen.
Firstly, linear small signal model was realized, and then the analysis was
extended to a nonlinear model of bipolar transistor. Results of such an
approach was a more accurate model for frequencies below 1 GHz, in
comparison to the literature. Measured scattering parameters were the basis
for the modelling. The nonlinear model of bipolar transistors consist of
four nonlinear elements: exponential emitter nonlinearity connected to the
base-emitter barrier dynamic resistance, diffusion capacitance of the same
barrier, collector-base barrier capacitance, and collector nonlinear
current source.
The last one include also avalanche break down nonlinearities. Passive
components modelling was also necessary to achieve better accuracy of the
selective amplifier model. This model is the first one which contain all
mentioned nonlinearities. Frequency characteristics of the model and
measured realized circuits were compared, and results are in satisfactorily
correspondence. Distortion measurements were performed as a function of
frequency and of load impedances. Analysis of simulation and measurements
results in the relation between third-order and second-order distortion. In
the literature such an explicit relationship can not be found for the
bipolar transistor amplifier.
The theoretical model was compared with the experimental circuit. The
measured data are in good correspondence with calculation results. On the
basis of applied analysis it is possible to minimize influences of the
second and third harmonic components if the dependence of the source and
load impedance on the fundamental frequency and frequency of second
harmonic is known.
Keywords: Small signal amplifier, Weak nonlinearity, Intermodulation distorsions, Volterra series, Bipolar junction transistor model, Nonlinear incremental model
- Type of paper
: Mentorship
Title:
Faculty: Fakultet elektrotehnike i računarstva Sveučilište u Zagrebu
Mentor: BARTOLIĆ JURAJ
Date of defense: 04/25/91
Number of pages: 175
Author: Hrabar mr.sc. Silvio
Degree level: M.A.
- Type of paper
: Mentorship
Title:
Faculty: Fakultet elektrotehnike i računarstva Sveučilište u Zagrebu
Mentor: ZENTNER ERVIN
Date of defense: 06/28/91
Number of pages: 123
Author: Šipuš mr. Zvonimir
Degree level: M.A.
- Type of paper
: Mentorship
Title:
Faculty: Fakultet elektrotehnike i računarstva Sveučilište u Zagrebu
Mentor: ZENTNER ERVIN
Date of defense: 06/28/91
Number of pages: 123
Author: Ahmić mr.sc. Rusmir
Degree level: M.A.
- Type of paper
: Mentorship
Title:
Faculty: Fakultet elektrotehnike i računarstva Sveučilište u Zagrebu
Mentor: BARTOLIĆ JURAJ
Date of defense: 02/23/93
Number of pages: 157
Author: Urh Zoran
Degree level: M.A.
- Type of paper
: Mentorship
Title:
Faculty: Fakultet elektrotehnike i računarstva Sveučilište u Zagrebu
Mentor: BARTOLIĆ JURAJ
Date of defense: 06/25/92
Number of pages: 165
Author: Miletić Alenka
Degree level: M.A.
- Type of paper
: Mentorship
Title: Microwave oscillator stabilization by use of cavity and
dielectric resonators
Faculty: Fakultet elektrotehnike i računarstva Sveučilište u Zagrebu
Mentor: ZENTNER ERVIN
Date of defense: 11/02/94
Number of pages: 125
Author: Hajdinjak Mladen
Degree level: M.A.
- Type of paper
: Mentorship
Title:
Faculty: Fakultet elektrotehnike i računarstva Sveučilište u Zagrebu
Mentor: ZENTNER ERVIN
Date of defense: 05/26/94
Number of pages: 110
Author: Polchert Svemir
Degree level: M.A.
- Type of paper
: Mentorship
Title:
- Type of paper
: Mentorship
Title:
Faculty: Fakultet elektrotehnike i računarstva Sveučilište u Zagrebu
Mentor: ZENTNER ERVIN
Date of defense: 11/03/93
Number of pages: 96
Author: Gašparović Renald
Degree level: M.A.
- Type of paper
: Mentorship
Title:
Faculty: Fakultet elektrotehnike i računarstva Sveučilište u Zagrebu
Mentor: ZENTNER ERVIN
Date of defense: 04/29/93
Number of pages: 145
Author: Drndelić Nenad
Degree level: M.A.
- Type of paper
: Mentorship
Title:
Faculty: Fakultet elektrotehnike i računarstva Sveučilište u Zagrebu
Mentor: ZENTNER ERVIN
Date of defense: 10/26/92
Number of pages: 171
Author: Vlašić Radovan
Degree level: M.A.
- Type of paper
: Mentorship
Title:
Faculty: Fakultet elektrotehnike i računarstva Sveučilište u Zagrebu
Mentor: ZENTNER ERVIN
Date of defense: 02/13/95
Number of pages: 160
Author: Čaušević Jasmina
Degree level: M.A.
- Type of paper
: Mentorship
Title:
Faculty: Fakultet elektrotehnike i računarstva Sveučilište u Zagrebu
Mentor: ZENTNER ERVIN
Date of defense: 04/27/95
Number of pages: 157
Author: Dimitrijević Miljenko
Degree level: M.A.
- Type of paper
: Survey/Study
Title:
- Authors:
- Nađ, Robert (33010)
Ordering party: Tvornica električnih kabela ELKA
Institution depot: Fakultet elektrotehnike i računarstva
Year: 1995
Number of pages: 49
Language: hrvatski
- Type of paper
: Survey/Study
Title: General plan of communication network for Croatian
Electric Power Supply System, 7. Radial radio networks
- Authors:
- Zentner, Ervin (54750)
Ordering party: Hrvatska Elektroprivreda
Institution depot: Fakultet elektrotehnike i računarstva
Year: 1994
Number of pages: 25
Language: hrvatski
- Type of paper
: Technical report
Title: Mobile radiocommunications
- Authors:
- Zentner, Ervin (54750)
- Bartolić, Juraj (2316)
Ordering party: Hrvatska Elektroprivreda
Institution depot: Fakultet elektrotehnike i računarstva
Year: 1993
Number of pages: 99
Language: hrvatski
- Type of paper
: Other
Title: Mobile radiocommunications
- Authors:
- Zentner, Ervin (54750)
- Bartolić, Juraj (2316)
Type of work: Seminar o novim tehnologijama, Zagreb, 29.-31.ožujak 1993.
Language: hrvatski
- Type of paper
: Other
Title:
- Authors:
- Zentner, Ervin (54750)
Type of work: Izvješće u okviru projekta EZ COST 243
Language: engleski
Summary: The research activities of the Institute for High Frequency
Technology have been described. Statistical destription of cumulative
sources which produced intermodulation interference in receivers are
analyzed. Based on the component signal statistics with Rayleigh, lognormal
or complex (Rayleigh and lognormal fluctuation superimposed) distribution
functions, a general expression for the distribution function of the third
order intermodulation products is set up. Radio noise level produced by
corona effect of high voltage overhead power transmission lines has been
investigated. Faraday shielding rooms and TEM cell have been developped and
manifactured in co-operation with the Institute for Electrical Engineering
Končar. The problem of nonlinearities in radiofrequency circuits,
especially amplifiers, have been investigated.
Keywords: Electromagnetic compatibility, interferences, nonlinear circuits
