Zeszyty czasopisma

Tom 73 (2022): Zeszyt 4 (August 2022)

Tom 73 (2022): Zeszyt 3 (June 2022)

Tom 73 (2022): Zeszyt 2 (April 2022)

Tom 73 (2022): Zeszyt 1 (February 2022)

Tom 72 (2021): Zeszyt 6 (December 2021)

Tom 72 (2021): Zeszyt 5 (September 2021)

Tom 72 (2021): Zeszyt 4 (August 2021)

Tom 72 (2021): Zeszyt 3 (June 2021)

Tom 72 (2021): Zeszyt 2 (April 2021)

Tom 72 (2021): Zeszyt 1 (February 2021)

Tom 71 (2020): Zeszyt 6 (December 2020)

Tom 71 (2020): Zeszyt 5 (September 2020)

Tom 71 (2020): Zeszyt 4 (August 2020)

Tom 71 (2020): Zeszyt 3 (June 2020)

Tom 71 (2020): Zeszyt 2 (April 2020)

Tom 71 (2020): Zeszyt 1 (February 2020)

Tom 70 (2019): Zeszyt 7 (December 2019)
Special Zeszyt

Tom 70 (2019): Zeszyt 6 (December 2019)

Tom 70 (2019): Zeszyt 5 (September 2019)

Tom 70 (2019): Zeszyt 4 (August 2019)

Tom 70 (2019): Zeszyt 3 (June 2019)

Tom 70 (2019): Zeszyt 2 (April 2019)

Tom 70 (2019): Zeszyt 1 (February 2019)

Tom 69 (2018): Zeszyt 6 (December 2018)

Tom 69 (2018): Zeszyt 5 (September 2018)

Tom 69 (2018): Zeszyt 4 (August 2018)

Tom 69 (2018): Zeszyt 3 (June 2018)

Tom 69 (2018): Zeszyt 2 (March 2018)

Tom 69 (2018): Zeszyt 1 (January 2018)

Tom 68 (2017): Zeszyt 7 (December 2017)

Tom 68 (2017): Zeszyt 6 (November 2017)

Tom 68 (2017): Zeszyt 5 (September 2017)

Tom 68 (2017): Zeszyt 4 (August 2017)

Tom 68 (2017): Zeszyt 3 (May 2017)

Tom 68 (2017): Zeszyt 2 (March 2017)

Tom 68 (2017): Zeszyt 1 (January 2017)

Tom 67 (2016): Zeszyt 6 (December 2016)

Tom 67 (2016): Zeszyt 5 (September 2016)

Tom 67 (2016): Zeszyt 4 (July 2016)

Tom 67 (2016): Zeszyt 3 (May 2016)

Tom 67 (2016): Zeszyt 2 (April 2016)

Tom 67 (2016): Zeszyt 1 (January 2016)

Tom 66 (2015): Zeszyt 6 (November 2015)

Tom 66 (2015): Zeszyt 5 (September 2015)

Tom 66 (2015): Zeszyt 4 (July 2015)

Tom 66 (2015): Zeszyt 3 (May 2015)

Tom 66 (2015): Zeszyt 2 (March 2015)

Tom 66 (2015): Zeszyt 1 (January 2015)

Tom 65 (2014): Zeszyt 6 (November 2014)

Tom 65 (2014): Zeszyt 5 (September 2014)

Tom 65 (2014): Zeszyt 4 (July 2014)

Tom 65 (2014): Zeszyt 3 (May 2014)

Tom 65 (2014): Zeszyt 2 (March 2014)

Tom 65 (2014): Zeszyt 1 (January 2014)

Tom 64 (2013): Zeszyt 6 (November 2013)

Tom 64 (2013): Zeszyt 5 (September 2013)

Tom 64 (2013): Zeszyt 4 (June 2013)

Tom 64 (2013): Zeszyt 3 (May 2013)

Tom 64 (2013): Zeszyt 2 (March 2013)

Tom 64 (2013): Zeszyt 1 (January 2013)

Tom 63 (2012): Zeszyt 6 (November 2012)

Tom 63 (2012): Zeszyt 5 (September 2012)

Tom 63 (2012): Zeszyt 4 (July 2012)

Tom 63 (2012): Zeszyt 3 (May 2012)

Tom 63 (2012): Zeszyt 2 (March 2012)

Tom 63 (2012): Zeszyt 1 (January 2012)

Tom 62 (2011): Zeszyt 6 (November 2011)

Tom 62 (2011): Zeszyt 5 (September 2011)

Tom 62 (2011): Zeszyt 4 (July 2011)

Tom 62 (2011): Zeszyt 3 (May 2011)

Tom 62 (2011): Zeszyt 2 (March 2011)

Tom 62 (2011): Zeszyt 1 (January 2011)

Tom 61 (2010): Zeszyt 6 (November 2010)

Tom 61 (2010): Zeszyt 5 (September 2010)

Tom 61 (2010): Zeszyt 4 (July 2010)

Tom 61 (2010): Zeszyt 3 (May 2010)

Tom 61 (2010): Zeszyt 2 (March 2010)

Tom 61 (2010): Zeszyt 1 (January 2010)

Informacje o czasopiśmie
Format
Czasopismo
eISSN
1339-309X
Pierwsze wydanie
07 Jun 2011
Częstotliwość wydawania
6 razy w roku
Języki
Angielski

Wyszukiwanie

Tom 71 (2020): Zeszyt 6 (December 2020)

Informacje o czasopiśmie
Format
Czasopismo
eISSN
1339-309X
Pierwsze wydanie
07 Jun 2011
Częstotliwość wydawania
6 razy w roku
Języki
Angielski

Wyszukiwanie

10 Artykułów
Otwarty dostęp

SARL: A reinforcement learning based QoS-aware IoT service discovery model

Data publikacji: 24 Dec 2020
Zakres stron: 368 - 378

Abstrakt

Abstract

The IoT environment includes the enormous amount of atomic services with dynamic QoS compared with traditional web services. In such an environment, in the service composition process, discovering a requested service meeting the required QoS is a di cult task. In this work, to address this issue, we propose a peer-to-peer-based service discovery model, which looks for the information about services meeting the requested QoS and functionality on an overlay constructed with users of services versus service nodes, with probably constrained resources. However, employing a plain discovery algorithm on the overlay network such as flooding, or k-random walk could cause high message overhead or delay. This necessitates an intelligent and adaptive discovery algorithm, which adapts itself based on users’ previous queries and the results. To fill this gap, the proposed service discovery approach is equipped with a reinforcement learning-based algorithm, named SARL. The reinforcement learning-based algorithm enables SARL to significantly reduce delay and message overhead in the service discovery process by ranking neighboring nodes based on users’ service request preferences and the service query results. The proposed model is implemented on the OMNet simulation platform. The simulation results demonstrate that SARL remarkably outperforms the existing approaches in terms of message overhead, reliability, timeliness, and energy usage efficiency.

Słowa kluczowe

  • internet of things
  • services discovery
  • reinforcement learning
Otwarty dostęp

Low-power latch comparator with accurate hysteresis control

Data publikacji: 24 Dec 2020
Zakres stron: 379 - 387

Abstrakt

Abstract

Recent research has focused on finding ways to control hysteresis of dynamic comparators. The current proposed techniques are based on either geometrical dimension adjustment or digital control. The first case does not allow for post fabrication control, while the second has limited accuracy. This paper presents a new dynamic comparator design with external hysteresis adjustment using an analog voltage. This is achieved by proposing an architecture including control devices with a specific sizing. This is performed with no significant increase of the design complexity, keeping the power consumption as low as possible. The design is analyzed, showing that the proposed solution allows accurate hysteresis adjustment without affecting the inherent circuit properties. The dynamic comparator is also implemented using a 180 nm commercially available CMOS technology. The results show that a variation of 550 mV of the control voltage allows an accurate hysteresis adjustment ranging from 0 to 40 mV, according to the input conditions. Moreover, the simplicity of the circuit in conjunction with the use of dynamic technology have allowed the best performances to be achieved compared to the current state of the art, in terms of energy with an FoM equal to 116 fJ/decision and silicon area of 180 µm2 .

Słowa kluczowe

  • dynamic comparator
  • hysteresis analysis
  • hysteresis control
  • low power
  • Schmitt trigger
Otwarty dostęp

Design and analysis of two degree of freedom tilt integral derivative controller with filter for frequency control and real time validation

Data publikacji: 24 Dec 2020
Zakres stron: 388 - 396

Abstrakt

Abstract

To deliver steady electric power with decent quality, intelligent and healthy control schemes are greatly necessary for automatic generation control (AGC) of power systems therefore, this work presents the design of two degree of freedom based tilt integral derivative controller with filter for AGC. Firstly, a two-area reheat thermal model is considered, and the gain of the controller are optimized by adaptive differential evolution method. The advantage of the suggested approach is validated by equating results with latest published approaches such as symbiotic organism search algorithm and articial bee colony tuned PID controller. Further, the suggested method is extended to a three unequal area thermal model and the performance of results are equated with teaching-learning based optimization-PIDD and firey algorithm-PID for the identical model. Lastly, the experiment of the proposed scheme has been employed in real-time simulation using OPAL-RT, for validation of its viability and cogency.

Słowa kluczowe

  • automatic generation control (AGC)
  • two degree of freedom (2DOF)
  • tilt integral derivative controller with filter (TIDF)
  • adaptive differential evolution (ADE) algorithm
  • robustness analysis
Otwarty dostęp

Impulse signals classification using one dimensional convolutional neural network

Data publikacji: 24 Dec 2020
Zakres stron: 397 - 405

Abstrakt

Abstract

The main purpose of this work is to propose a modern one-dimensional convolutional neural network (1 D CNN) configurations for distinguishing separate PD impulses from different types of PD sources while the parameters of these sources are changed. Three PD sources were built for signal generation: corona discharge, discharge in a void, and surface discharge. The reason for using separate PD impulses for classification is to develop a universal tool with the ability to recognize an insulation defects by analysing very few events in the insulation in a short range of time. Additionally, we found the optimal sample rates for the data acquisition for these network configurations. The necessity of signal filtering was also tested. The following configurations of a neural network were proposed: configuration for classification raw PD impulses; configuration for classification of PD impulses represented by power spectral density, for both filtered and unfiltered variants.

Słowa kluczowe

  • convolutional neural networks
  • one-dimensional convolutional neural network
  • partial discharge
  • signal analysis
Otwarty dostęp

Optical properties of electrochemically etched N-type silicon wafers for solar cell applications

Data publikacji: 24 Dec 2020
Zakres stron: 406 - 412

Abstrakt

Abstract

The presented experiments and studies are intended for photovoltaic applications of crystalline silicon. This work deals with chemical treatment of the surface of n-type silicon wafers with different resistivity to reduce their reflectivity. Chemical surface treatment of silicon is an alternative method to using the antireflection layer. Optical losses caused by the reflection of light from the surface of the solar cells significantly reduce their efficiency. The investigated samples were prepared by the electrochemical etching method in the solution based on hydrofluoric acid and ethanol. The analysis of the prepared samples is divided into two parts, namely experimental measurements, and theoretical modeling. Experimental measurements are performed using UV-VIS spectroscopy, spectroscopic ellipsometry and SEM microscopy. Theoretical modeling is based on the construction and optimization of theoretical model of optical response (reflectivity and ellipsometric parameters) to determine the effective refractive index and thickness of formed structure. Effective refractive index of studied samples in theoretical model of optical response is based on Looyenga effective medium approximation and Tauc-Lorentz dispersion model.

Słowa kluczowe

  • electrochemical etching
  • effective medium approximation
  • Looyenga EMA
  • modified Fresnel coefficients
  • reflectivity
  • Tauc-Lorentz dispersion model
Otwarty dostęp

The study of electrohydrodynamic printing by numerical simulation

Data publikacji: 24 Dec 2020
Zakres stron: 413 - 418

Abstrakt

Abstract

EHD (Electrohydrodynamic) printing is a promising technique for alternative fabrication of highresolution micro- and nanostructures without employment of any molds or photo-masks However, the printing precision can be easily influenced by the printing conditions, such as applied voltage, printing distance (the distance between the nozzle tip and the substrate), and flow rate. Unfortunately, up to now there was no work which analyzed those influencing factors in-depth and systematically by theory and numerical simulation. In this paper, the theory of EHD printing was presented and the effect of applied voltage, printing distance, and flow rate on the width of printed line was analyzed by numerical simulation. The simulation results showed that the width of printed lines is proportional to printing distance, nozzle size, and flow rate. However, it is inversely proportional to the applied voltage.

Słowa kluczowe

  • electrohydrodynamic printing
  • numerical simulation
  • electrohydrodynamic theory
  • printing nozzle
Otwarty dostęp

A low profile compact three-way Wilkinson power divider with size reduction

Data publikacji: 24 Dec 2020
Zakres stron: 419 - 422

Abstrakt

Abstract

In this study, a three-way Wilkinson power divider (WPD) was proposed the circuit whose center frequency was selected as 1.9 GHz operates between 0.95-2.95 GHz frequencies and has a bandwidth of approximately 105%. The simulation and measurement results of the designed circuit were well aligned with each other below 10 dB return loss and 13 dB isolation. In addition, 0.4, 0.3 and 1.0 dB insertion loss were obtained in the output ways, respectively. The circuit is made more compact thanks to the curved structure of the output ways. It has been found that the proposed three-way power divider takes about 35% less space than the conventional circuit design.

Słowa kluczowe

  • Wilkinson power divider
  • size reduction
  • 3 way power divider
  • compact WPD
Otwarty dostęp

Design and miniaturization of dual-band Wilkinson power dividers

Data publikacji: 24 Dec 2020
Zakres stron: 423 - 427

Abstrakt

Abstract

In this paper, four differently shaped Wilkinson power dividers are presented by selecting the same physical length of two-section transmission lines, dual arbitrary frequency band Wilkinson power dividers can be achieved. The 2.4 GHz (WLAN) and 5.9 GHz (DSRC IEEE 802.11p) frequency bands are selected to complement the future development of multi-band, multi-standard transceivers. To improve physical separation and electrical isolation between the two output ports a parallel RLC circuit is employed. For verification, the simulated and measured performance results of dual-band Wilkinson power dividers implemented on the Rogers 4003C laminate are presented. The measurement results for the fabricated Wilkinson power dividers were in good agreement with theoretical simulation results and show dual-band characteristics.

Słowa kluczowe

  • dual-band
  • DSRC
  • RF/microwave circuit
  • Rogers 4003C
  • Wilkinson power divider (WPD)
Otwarty dostęp

Design of microwave lowpass filter based on log periodic zigzag DGS

Data publikacji: 24 Dec 2020
Zakres stron: 428 - 432

Abstrakt

Abstract

This contribution presents, for the first time, the design of microwave lowpass filter with ultrawide stopband and low insertion loss based on the log-periodic zig-zag defected ground structure (DGS); the design is specifically evolved from the principle of the log-periodic line antenna and the slotline based DGS. Based on the log-periodic property, studies show that ultra-wideband suppression can be realized by increasing the flare angle or the angle subtended by each element of the slotline DGS. The developed filter therefore shows low insertion loss of 0.7 dB within the passband, sharp transition between the passband and the stopband and ultra-wide suppression band from 2.61-26.5 GHz with a 20 dB suppression level. The DGS architecture is simple and easy to realize, and the design is thus useful in many microwave applications. The fabricated prototype filter validates the study, both from simulations and from measurements.

Słowa kluczowe

  • log periodic
  • zigzag
  • slotline
  • defected ground structure (DGS)
  • microwave filter
Otwarty dostęp

Dual-mode resonator filter with improved feed-lines for dual-band applications

Data publikacji: 24 Dec 2020
Zakres stron: 433 - 435

Abstrakt

Abstract

An improved feedline configuration for dual-mode resonator filter is investigated in this paper. Based on the introduced topology, a dual-mode dual-band bandpass filter with center frequencies of 1.8 and 2.4 GHz is optimally designed, fabricated and tested. The introduced dual-band bandpass filter has simple structure and enables high selectivity to be realized due to two pairs of transmission zeros located near to the lower and upper passband, respectively. Both measured and simulated performances are presented with good consistency.

Słowa kluczowe

  • dual mode
  • dual band
  • bandpass
  • filter
10 Artykułów
Otwarty dostęp

SARL: A reinforcement learning based QoS-aware IoT service discovery model

Data publikacji: 24 Dec 2020
Zakres stron: 368 - 378

Abstrakt

Abstract

The IoT environment includes the enormous amount of atomic services with dynamic QoS compared with traditional web services. In such an environment, in the service composition process, discovering a requested service meeting the required QoS is a di cult task. In this work, to address this issue, we propose a peer-to-peer-based service discovery model, which looks for the information about services meeting the requested QoS and functionality on an overlay constructed with users of services versus service nodes, with probably constrained resources. However, employing a plain discovery algorithm on the overlay network such as flooding, or k-random walk could cause high message overhead or delay. This necessitates an intelligent and adaptive discovery algorithm, which adapts itself based on users’ previous queries and the results. To fill this gap, the proposed service discovery approach is equipped with a reinforcement learning-based algorithm, named SARL. The reinforcement learning-based algorithm enables SARL to significantly reduce delay and message overhead in the service discovery process by ranking neighboring nodes based on users’ service request preferences and the service query results. The proposed model is implemented on the OMNet simulation platform. The simulation results demonstrate that SARL remarkably outperforms the existing approaches in terms of message overhead, reliability, timeliness, and energy usage efficiency.

Słowa kluczowe

  • internet of things
  • services discovery
  • reinforcement learning
Otwarty dostęp

Low-power latch comparator with accurate hysteresis control

Data publikacji: 24 Dec 2020
Zakres stron: 379 - 387

Abstrakt

Abstract

Recent research has focused on finding ways to control hysteresis of dynamic comparators. The current proposed techniques are based on either geometrical dimension adjustment or digital control. The first case does not allow for post fabrication control, while the second has limited accuracy. This paper presents a new dynamic comparator design with external hysteresis adjustment using an analog voltage. This is achieved by proposing an architecture including control devices with a specific sizing. This is performed with no significant increase of the design complexity, keeping the power consumption as low as possible. The design is analyzed, showing that the proposed solution allows accurate hysteresis adjustment without affecting the inherent circuit properties. The dynamic comparator is also implemented using a 180 nm commercially available CMOS technology. The results show that a variation of 550 mV of the control voltage allows an accurate hysteresis adjustment ranging from 0 to 40 mV, according to the input conditions. Moreover, the simplicity of the circuit in conjunction with the use of dynamic technology have allowed the best performances to be achieved compared to the current state of the art, in terms of energy with an FoM equal to 116 fJ/decision and silicon area of 180 µm2 .

Słowa kluczowe

  • dynamic comparator
  • hysteresis analysis
  • hysteresis control
  • low power
  • Schmitt trigger
Otwarty dostęp

Design and analysis of two degree of freedom tilt integral derivative controller with filter for frequency control and real time validation

Data publikacji: 24 Dec 2020
Zakres stron: 388 - 396

Abstrakt

Abstract

To deliver steady electric power with decent quality, intelligent and healthy control schemes are greatly necessary for automatic generation control (AGC) of power systems therefore, this work presents the design of two degree of freedom based tilt integral derivative controller with filter for AGC. Firstly, a two-area reheat thermal model is considered, and the gain of the controller are optimized by adaptive differential evolution method. The advantage of the suggested approach is validated by equating results with latest published approaches such as symbiotic organism search algorithm and articial bee colony tuned PID controller. Further, the suggested method is extended to a three unequal area thermal model and the performance of results are equated with teaching-learning based optimization-PIDD and firey algorithm-PID for the identical model. Lastly, the experiment of the proposed scheme has been employed in real-time simulation using OPAL-RT, for validation of its viability and cogency.

Słowa kluczowe

  • automatic generation control (AGC)
  • two degree of freedom (2DOF)
  • tilt integral derivative controller with filter (TIDF)
  • adaptive differential evolution (ADE) algorithm
  • robustness analysis
Otwarty dostęp

Impulse signals classification using one dimensional convolutional neural network

Data publikacji: 24 Dec 2020
Zakres stron: 397 - 405

Abstrakt

Abstract

The main purpose of this work is to propose a modern one-dimensional convolutional neural network (1 D CNN) configurations for distinguishing separate PD impulses from different types of PD sources while the parameters of these sources are changed. Three PD sources were built for signal generation: corona discharge, discharge in a void, and surface discharge. The reason for using separate PD impulses for classification is to develop a universal tool with the ability to recognize an insulation defects by analysing very few events in the insulation in a short range of time. Additionally, we found the optimal sample rates for the data acquisition for these network configurations. The necessity of signal filtering was also tested. The following configurations of a neural network were proposed: configuration for classification raw PD impulses; configuration for classification of PD impulses represented by power spectral density, for both filtered and unfiltered variants.

Słowa kluczowe

  • convolutional neural networks
  • one-dimensional convolutional neural network
  • partial discharge
  • signal analysis
Otwarty dostęp

Optical properties of electrochemically etched N-type silicon wafers for solar cell applications

Data publikacji: 24 Dec 2020
Zakres stron: 406 - 412

Abstrakt

Abstract

The presented experiments and studies are intended for photovoltaic applications of crystalline silicon. This work deals with chemical treatment of the surface of n-type silicon wafers with different resistivity to reduce their reflectivity. Chemical surface treatment of silicon is an alternative method to using the antireflection layer. Optical losses caused by the reflection of light from the surface of the solar cells significantly reduce their efficiency. The investigated samples were prepared by the electrochemical etching method in the solution based on hydrofluoric acid and ethanol. The analysis of the prepared samples is divided into two parts, namely experimental measurements, and theoretical modeling. Experimental measurements are performed using UV-VIS spectroscopy, spectroscopic ellipsometry and SEM microscopy. Theoretical modeling is based on the construction and optimization of theoretical model of optical response (reflectivity and ellipsometric parameters) to determine the effective refractive index and thickness of formed structure. Effective refractive index of studied samples in theoretical model of optical response is based on Looyenga effective medium approximation and Tauc-Lorentz dispersion model.

Słowa kluczowe

  • electrochemical etching
  • effective medium approximation
  • Looyenga EMA
  • modified Fresnel coefficients
  • reflectivity
  • Tauc-Lorentz dispersion model
Otwarty dostęp

The study of electrohydrodynamic printing by numerical simulation

Data publikacji: 24 Dec 2020
Zakres stron: 413 - 418

Abstrakt

Abstract

EHD (Electrohydrodynamic) printing is a promising technique for alternative fabrication of highresolution micro- and nanostructures without employment of any molds or photo-masks However, the printing precision can be easily influenced by the printing conditions, such as applied voltage, printing distance (the distance between the nozzle tip and the substrate), and flow rate. Unfortunately, up to now there was no work which analyzed those influencing factors in-depth and systematically by theory and numerical simulation. In this paper, the theory of EHD printing was presented and the effect of applied voltage, printing distance, and flow rate on the width of printed line was analyzed by numerical simulation. The simulation results showed that the width of printed lines is proportional to printing distance, nozzle size, and flow rate. However, it is inversely proportional to the applied voltage.

Słowa kluczowe

  • electrohydrodynamic printing
  • numerical simulation
  • electrohydrodynamic theory
  • printing nozzle
Otwarty dostęp

A low profile compact three-way Wilkinson power divider with size reduction

Data publikacji: 24 Dec 2020
Zakres stron: 419 - 422

Abstrakt

Abstract

In this study, a three-way Wilkinson power divider (WPD) was proposed the circuit whose center frequency was selected as 1.9 GHz operates between 0.95-2.95 GHz frequencies and has a bandwidth of approximately 105%. The simulation and measurement results of the designed circuit were well aligned with each other below 10 dB return loss and 13 dB isolation. In addition, 0.4, 0.3 and 1.0 dB insertion loss were obtained in the output ways, respectively. The circuit is made more compact thanks to the curved structure of the output ways. It has been found that the proposed three-way power divider takes about 35% less space than the conventional circuit design.

Słowa kluczowe

  • Wilkinson power divider
  • size reduction
  • 3 way power divider
  • compact WPD
Otwarty dostęp

Design and miniaturization of dual-band Wilkinson power dividers

Data publikacji: 24 Dec 2020
Zakres stron: 423 - 427

Abstrakt

Abstract

In this paper, four differently shaped Wilkinson power dividers are presented by selecting the same physical length of two-section transmission lines, dual arbitrary frequency band Wilkinson power dividers can be achieved. The 2.4 GHz (WLAN) and 5.9 GHz (DSRC IEEE 802.11p) frequency bands are selected to complement the future development of multi-band, multi-standard transceivers. To improve physical separation and electrical isolation between the two output ports a parallel RLC circuit is employed. For verification, the simulated and measured performance results of dual-band Wilkinson power dividers implemented on the Rogers 4003C laminate are presented. The measurement results for the fabricated Wilkinson power dividers were in good agreement with theoretical simulation results and show dual-band characteristics.

Słowa kluczowe

  • dual-band
  • DSRC
  • RF/microwave circuit
  • Rogers 4003C
  • Wilkinson power divider (WPD)
Otwarty dostęp

Design of microwave lowpass filter based on log periodic zigzag DGS

Data publikacji: 24 Dec 2020
Zakres stron: 428 - 432

Abstrakt

Abstract

This contribution presents, for the first time, the design of microwave lowpass filter with ultrawide stopband and low insertion loss based on the log-periodic zig-zag defected ground structure (DGS); the design is specifically evolved from the principle of the log-periodic line antenna and the slotline based DGS. Based on the log-periodic property, studies show that ultra-wideband suppression can be realized by increasing the flare angle or the angle subtended by each element of the slotline DGS. The developed filter therefore shows low insertion loss of 0.7 dB within the passband, sharp transition between the passband and the stopband and ultra-wide suppression band from 2.61-26.5 GHz with a 20 dB suppression level. The DGS architecture is simple and easy to realize, and the design is thus useful in many microwave applications. The fabricated prototype filter validates the study, both from simulations and from measurements.

Słowa kluczowe

  • log periodic
  • zigzag
  • slotline
  • defected ground structure (DGS)
  • microwave filter
Otwarty dostęp

Dual-mode resonator filter with improved feed-lines for dual-band applications

Data publikacji: 24 Dec 2020
Zakres stron: 433 - 435

Abstrakt

Abstract

An improved feedline configuration for dual-mode resonator filter is investigated in this paper. Based on the introduced topology, a dual-mode dual-band bandpass filter with center frequencies of 1.8 and 2.4 GHz is optimally designed, fabricated and tested. The introduced dual-band bandpass filter has simple structure and enables high selectivity to be realized due to two pairs of transmission zeros located near to the lower and upper passband, respectively. Both measured and simulated performances are presented with good consistency.

Słowa kluczowe

  • dual mode
  • dual band
  • bandpass
  • filter

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