IEEE Antennas and Propagation Society International Symposium. 1998 Digest. Antennas: Gateways to the Global Network. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.98CH36194), 1998
IEEE Antennas and Propagation Society International Symposium. 2001 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.01CH37229), 2001
IEEE Antennas and Propagation Society International Symposium. 1999 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.99CH37010), 1999
IEEE Antennas and Propagation Society International Symposium. 1995 Digest, 1995
... Daniel J. Bem, Pawel Kabacik* Technical University of Wroclaw Institute of Telecommunications... more ... Daniel J. Bem, Pawel Kabacik* Technical University of Wroclaw Institute of Telecommunications and Acoustics Wybrzeze Wyspiatiskiego 27 50-370 Wroclaw, Poland ... The overall MI'A loss budget is suiiiarizcd in 'I'ablc I . Apat-t iioni the BFN losses, there are also scanning losses ...
13th International Conference on Microwaves, Radar and Wireless Communications. MIKON - 2000. Conference Proceedings (IEEE Cat. No.00EX428), 2000
The paper presents an outline of the most important problems related to the development of advanc... more The paper presents an outline of the most important problems related to the development of advanced base station antennas which are referred to as smart antennas. They are needed by new generations of mobile communications systems. Smart antennas involve not only RF components but also a broad segment of digital beamforming and digital signal processing units
The paper presents a concept of the cylindrical antenna for broadband networks to be deployed on ... more The paper presents a concept of the cylindrical antenna for broadband networks to be deployed on seas and oceans where traffic is dense. An important leading application of cylindrical antenna arrays, are becoming broadband wireless systems with mobile nodes and ad-hoc set-up topology. One of the main network types is the IEEE 802.16-2004 standard designed for long-range wireless broadband access. It uses a TDMA-based scheme in media access control (MAC) level and orthogonal frequency division multiplexing (OFDM) at the physical layer. At the MAC layer the IEEE 802.16d supports two modes, point-to-multi-point (PMP) mode and mesh mode. The main reasons driving interests in the cylindrical antennas for such networks, is their ability to provide gain advantage for radio link budget and offering design opportunities to spatial access. The presented cylindrical antenna array is able to provide, either overlapping several sector beams or by little disturbed omnidirectional pattern in the ...
IEEE Antennas and Propagation Society International Symposium. Transmitting Waves of Progress to the Next Millennium. 2000 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.00CH37118), 2000
Research on advanced antenna array designs calls for sophisticated measuring techniques to diagno... more Research on advanced antenna array designs calls for sophisticated measuring techniques to diagnose the actual properties of the array models. These methods should provide not only the characteristics of the AUT (expressed in terms of standard parameters), but also the actual current distributions for the array aperture. Knowing the amplitude and phase distributions of the currents in the antenna aperture,
2007 IEEE Antennas and Propagation International Symposium, 2007
This paper presents use of this measuring system to determine radiation efficiency of small anten... more This paper presents use of this measuring system to determine radiation efficiency of small antennas with the direct approach, by integration field components onto the spherical radiation pattern.
Proceedings of the 16th International Symposium on Power Semiconductor Devices & IC's, 2003
Antennas for portable terminals are to be small and preferably mounted inside a case. Due to clus... more Antennas for portable terminals are to be small and preferably mounted inside a case. Due to clustering of mobile system bands there is an urgent need for antennas providing wide bands amongst others (500 MHz or more). When the operation over the desired number of bands is met, it is necessary to provide required bandwidth in each of the designated bands. To achieve this suitable means of tuning an antenna in separate bands are required. This is not a simple task because the ratio between the lowest and the highest frequency can exceed the number of seven. The broad range of tuning is needed for keeping a small number of antenna types, so a manufacturer can take advantage of cost-effectiveness.
2005 IEEE Antennas and Propagation Society International Symposium, 2005
ABSTRACT The intensive research on terminal antennas in recent years examined new ideas that resu... more ABSTRACT The intensive research on terminal antennas in recent years examined new ideas that resulted in the formulation of guidelines on how specific antenna parameters could be accomplished. Among the more challenging variables in obtaining parameters, two gained our particular attention: a broad bandwidth and a radiation pattern that does not produce SAR values exceeding the permissible level. Broadening the bandwidth at the lowest resonance in multiresonant antennas featuring the highest possible scale of miniaturization was the most difficult task. Owing to the possible highest scale of miniaturization, various modifications of PIFAs have attracted much attention. We present an equivalent circuit model for a dual-band antenna. The model reflects the importance of a strong mutual coupling in miniaturized PIFAs. Providing very broad bandwidths with highly miniaturized antenna was possible when parts of the PIFA element were inserted into the slits in the small ground plate. The measured efficiency values are high and meet the expectations of modern wireless device designers.
15th International Conference on Microwaves, Radar and Wireless Communications (IEEE Cat. No.04EX824), 2004
ABSTRACT The paper presents investigations into single layer and stacked configurations of a PIFA... more ABSTRACT The paper presents investigations into single layer and stacked configurations of a PIFA terminal antenna for multiband operation. Our findings show that the stacked patch configuration is difficult to tune in individual subbands and the attainable bands are not as broad as for a single layer counterpart. Increasing the operational bandwidth of a single layer PIFA can be achieved by folding and tapering the patch conductor, as well as by careful trimming its coupling to the ground plane.
2007 IEEE Antennas and Propagation International Symposium, 2007
ABSTRACT Domination of PIFAs could have satisfied demands set by designers of portable terminals ... more ABSTRACT Domination of PIFAs could have satisfied demands set by designers of portable terminals for almost a decade. However, any other form of high efficiency antenna featuring a high degree of miniaturization raises interest both in terms of electromagnetic phenomenon explored and in terms of potential practical uses. Furthermore, some subtle details - neglected during research works - may gain a status go or no go factor in mass market uses. Driven with this motivation we put much attention in our studies into antenna miniaturization with other means than barely the PIFA concept. To bandwidth properties in miniature antennas, a paramount importance has an interaction between the ground and the element. Focus on this interaction turned out to be key to invent coaxially fed miniature antennas without any short which is presented in this paper.
2007 IEEE Antennas and Propagation International Symposium, 2007
ABSTRACT Various designs of dual or more band planar inverted-F antennas (PIFAs) were manufacture... more ABSTRACT Various designs of dual or more band planar inverted-F antennas (PIFAs) were manufactured perhaps well in excess of a billion pieces over the last decade. Most PIFAs are single layer antenna elements with a volume of 3 to 7 cm3. Presently, there is a growing number of emerging applications which apparently call for other antenna concepts. The reasons could differ and range from a bandwidth beyond that available with PIFAs to wearable antennas made on fine substrates and operating in a strongly varying environment. Our research had addressed an emerging class of antenna for servers wirelessly serving commercial electronics. Antenna should be capable of being accommodated in many manners - on a PCB, at the front panel, as a plug-in device, in planar or conformal shape.
2006 First European Conference on Antennas and Propagation, 2006
ABSTRACT The paper presents investigations into compact zero-thickness wideband antennas capable ... more ABSTRACT The paper presents investigations into compact zero-thickness wideband antennas capable of operating in many frequency bands within 800-3000 MHz. Multi-band operation of these antennas is accomplished by suitable meandering of conducting segments that may be supported by a thin dielectric film. The antennas are capable of operating with a very small ground plane formed by an adjacent conducting surface or a feeding transmission line. Because of the use of flexible materials, these antennas can be conformed to planar or cylindrical structures. Their operation is tested experimentally in stand-alone configurations as well as in the presence of enclosures.
2006 First European Conference on Antennas and Propagation, 2006
The paper describes a system for measuring radiation efficiency of a small antenna operating alon... more The paper describes a system for measuring radiation efficiency of a small antenna operating alone or in the presence of objects similar to those as in an actual service. The system applies the direct approach to determining the antenna efficiency by measuring the radiated field over the entire sphere surrounding the tested antenna. In order to overcome problems associated with
2006 First European Conference on Antennas and Propagation, 2006
The paper describes a high fidelity system for measuring a radiation pattern of an electrically s... more The paper describes a high fidelity system for measuring a radiation pattern of an electrically small antenna. In this system, the antenna under test (AUT) equipped with a battery powered signal generator is suspended by a dielectric foam in the centre of a pair of dielectric rings that are supported by a pedestal of a spherical positioning mechanical sub-system. Radiation patterns are obtained directly in spherical format using a suitably constructed probe antenna of linear or circular polarization. Measurements are controlled by a computer, which also stores and processes the measured data. The results reveal considerable differences between the radiation patterns of a small antenna obtained using the proposed wireless approach and the conventional one, in which the antenna is connected with a cable to the receiver.
IEEE Antennas and Propagation Society International Symposium. 1998 Digest. Antennas: Gateways to the Global Network. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.98CH36194), 1998
IEEE Antennas and Propagation Society International Symposium. 2001 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.01CH37229), 2001
IEEE Antennas and Propagation Society International Symposium. 1999 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.99CH37010), 1999
IEEE Antennas and Propagation Society International Symposium. 1995 Digest, 1995
... Daniel J. Bem, Pawel Kabacik* Technical University of Wroclaw Institute of Telecommunications... more ... Daniel J. Bem, Pawel Kabacik* Technical University of Wroclaw Institute of Telecommunications and Acoustics Wybrzeze Wyspiatiskiego 27 50-370 Wroclaw, Poland ... The overall MI'A loss budget is suiiiarizcd in 'I'ablc I . Apat-t iioni the BFN losses, there are also scanning losses ...
13th International Conference on Microwaves, Radar and Wireless Communications. MIKON - 2000. Conference Proceedings (IEEE Cat. No.00EX428), 2000
The paper presents an outline of the most important problems related to the development of advanc... more The paper presents an outline of the most important problems related to the development of advanced base station antennas which are referred to as smart antennas. They are needed by new generations of mobile communications systems. Smart antennas involve not only RF components but also a broad segment of digital beamforming and digital signal processing units
The paper presents a concept of the cylindrical antenna for broadband networks to be deployed on ... more The paper presents a concept of the cylindrical antenna for broadband networks to be deployed on seas and oceans where traffic is dense. An important leading application of cylindrical antenna arrays, are becoming broadband wireless systems with mobile nodes and ad-hoc set-up topology. One of the main network types is the IEEE 802.16-2004 standard designed for long-range wireless broadband access. It uses a TDMA-based scheme in media access control (MAC) level and orthogonal frequency division multiplexing (OFDM) at the physical layer. At the MAC layer the IEEE 802.16d supports two modes, point-to-multi-point (PMP) mode and mesh mode. The main reasons driving interests in the cylindrical antennas for such networks, is their ability to provide gain advantage for radio link budget and offering design opportunities to spatial access. The presented cylindrical antenna array is able to provide, either overlapping several sector beams or by little disturbed omnidirectional pattern in the ...
IEEE Antennas and Propagation Society International Symposium. Transmitting Waves of Progress to the Next Millennium. 2000 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.00CH37118), 2000
Research on advanced antenna array designs calls for sophisticated measuring techniques to diagno... more Research on advanced antenna array designs calls for sophisticated measuring techniques to diagnose the actual properties of the array models. These methods should provide not only the characteristics of the AUT (expressed in terms of standard parameters), but also the actual current distributions for the array aperture. Knowing the amplitude and phase distributions of the currents in the antenna aperture,
2007 IEEE Antennas and Propagation International Symposium, 2007
This paper presents use of this measuring system to determine radiation efficiency of small anten... more This paper presents use of this measuring system to determine radiation efficiency of small antennas with the direct approach, by integration field components onto the spherical radiation pattern.
Proceedings of the 16th International Symposium on Power Semiconductor Devices & IC's, 2003
Antennas for portable terminals are to be small and preferably mounted inside a case. Due to clus... more Antennas for portable terminals are to be small and preferably mounted inside a case. Due to clustering of mobile system bands there is an urgent need for antennas providing wide bands amongst others (500 MHz or more). When the operation over the desired number of bands is met, it is necessary to provide required bandwidth in each of the designated bands. To achieve this suitable means of tuning an antenna in separate bands are required. This is not a simple task because the ratio between the lowest and the highest frequency can exceed the number of seven. The broad range of tuning is needed for keeping a small number of antenna types, so a manufacturer can take advantage of cost-effectiveness.
2005 IEEE Antennas and Propagation Society International Symposium, 2005
ABSTRACT The intensive research on terminal antennas in recent years examined new ideas that resu... more ABSTRACT The intensive research on terminal antennas in recent years examined new ideas that resulted in the formulation of guidelines on how specific antenna parameters could be accomplished. Among the more challenging variables in obtaining parameters, two gained our particular attention: a broad bandwidth and a radiation pattern that does not produce SAR values exceeding the permissible level. Broadening the bandwidth at the lowest resonance in multiresonant antennas featuring the highest possible scale of miniaturization was the most difficult task. Owing to the possible highest scale of miniaturization, various modifications of PIFAs have attracted much attention. We present an equivalent circuit model for a dual-band antenna. The model reflects the importance of a strong mutual coupling in miniaturized PIFAs. Providing very broad bandwidths with highly miniaturized antenna was possible when parts of the PIFA element were inserted into the slits in the small ground plate. The measured efficiency values are high and meet the expectations of modern wireless device designers.
15th International Conference on Microwaves, Radar and Wireless Communications (IEEE Cat. No.04EX824), 2004
ABSTRACT The paper presents investigations into single layer and stacked configurations of a PIFA... more ABSTRACT The paper presents investigations into single layer and stacked configurations of a PIFA terminal antenna for multiband operation. Our findings show that the stacked patch configuration is difficult to tune in individual subbands and the attainable bands are not as broad as for a single layer counterpart. Increasing the operational bandwidth of a single layer PIFA can be achieved by folding and tapering the patch conductor, as well as by careful trimming its coupling to the ground plane.
2007 IEEE Antennas and Propagation International Symposium, 2007
ABSTRACT Domination of PIFAs could have satisfied demands set by designers of portable terminals ... more ABSTRACT Domination of PIFAs could have satisfied demands set by designers of portable terminals for almost a decade. However, any other form of high efficiency antenna featuring a high degree of miniaturization raises interest both in terms of electromagnetic phenomenon explored and in terms of potential practical uses. Furthermore, some subtle details - neglected during research works - may gain a status go or no go factor in mass market uses. Driven with this motivation we put much attention in our studies into antenna miniaturization with other means than barely the PIFA concept. To bandwidth properties in miniature antennas, a paramount importance has an interaction between the ground and the element. Focus on this interaction turned out to be key to invent coaxially fed miniature antennas without any short which is presented in this paper.
2007 IEEE Antennas and Propagation International Symposium, 2007
ABSTRACT Various designs of dual or more band planar inverted-F antennas (PIFAs) were manufacture... more ABSTRACT Various designs of dual or more band planar inverted-F antennas (PIFAs) were manufactured perhaps well in excess of a billion pieces over the last decade. Most PIFAs are single layer antenna elements with a volume of 3 to 7 cm3. Presently, there is a growing number of emerging applications which apparently call for other antenna concepts. The reasons could differ and range from a bandwidth beyond that available with PIFAs to wearable antennas made on fine substrates and operating in a strongly varying environment. Our research had addressed an emerging class of antenna for servers wirelessly serving commercial electronics. Antenna should be capable of being accommodated in many manners - on a PCB, at the front panel, as a plug-in device, in planar or conformal shape.
2006 First European Conference on Antennas and Propagation, 2006
ABSTRACT The paper presents investigations into compact zero-thickness wideband antennas capable ... more ABSTRACT The paper presents investigations into compact zero-thickness wideband antennas capable of operating in many frequency bands within 800-3000 MHz. Multi-band operation of these antennas is accomplished by suitable meandering of conducting segments that may be supported by a thin dielectric film. The antennas are capable of operating with a very small ground plane formed by an adjacent conducting surface or a feeding transmission line. Because of the use of flexible materials, these antennas can be conformed to planar or cylindrical structures. Their operation is tested experimentally in stand-alone configurations as well as in the presence of enclosures.
2006 First European Conference on Antennas and Propagation, 2006
The paper describes a system for measuring radiation efficiency of a small antenna operating alon... more The paper describes a system for measuring radiation efficiency of a small antenna operating alone or in the presence of objects similar to those as in an actual service. The system applies the direct approach to determining the antenna efficiency by measuring the radiated field over the entire sphere surrounding the tested antenna. In order to overcome problems associated with
2006 First European Conference on Antennas and Propagation, 2006
The paper describes a high fidelity system for measuring a radiation pattern of an electrically s... more The paper describes a high fidelity system for measuring a radiation pattern of an electrically small antenna. In this system, the antenna under test (AUT) equipped with a battery powered signal generator is suspended by a dielectric foam in the centre of a pair of dielectric rings that are supported by a pedestal of a spherical positioning mechanical sub-system. Radiation patterns are obtained directly in spherical format using a suitably constructed probe antenna of linear or circular polarization. Measurements are controlled by a computer, which also stores and processes the measured data. The results reveal considerable differences between the radiation patterns of a small antenna obtained using the proposed wireless approach and the conventional one, in which the antenna is connected with a cable to the receiver.
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Papers by P. Kabacik