| 1. |
- Glazunov, Andres Alayon, 1969, et al.
(författare)
-
Devising a Horizontal Chamber Array for Automotive OTA Tests in Random Line-Of-Sight
- 2016
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Ingår i: International Symposium on Antennas and Propagation (ISAP), Hobart, Australia, 9-12 November, 2015. ; , s. Art. no. 7447285-
-
Konferensbidrag (refereegranskat)abstract
- In this paper we propose an approach to design a horizontal array antenna to reduce the uncertainty of reference measurements in Random Line-Of-Sight Over-The-Air testing in anechoic chambers. The main focus is on wireless communications testing to and from automotive vehicles. The proposed procedure allows to determine the size, the spacing and the number of elements of a horizontal array antenna resulting in an absolute error less than 1 dB. The analysis is based on presenting the output of the ideal digital threshold receiver model of the device under test as a Probability of Detection curve.
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| 2. |
- Glazunov, Andres Alayon, 1969, et al.
(författare)
-
Impact of the Spatial User Distribution on the Coverage Antenna Pattern of Maximum Ratio Combining in Random Line-Of-Sight
- 2015
-
Ingår i: 9th European Conference on Antennas and Propagation, EuCAP 2015, Lisbon, Portugal, 13-17 May 2015. - 9788890701856
-
Konferensbidrag (refereegranskat)abstract
- In this paper we investigate the impact of the spatial user distribution on the Maximum Ratio Combining (MRC) of the output signals from an ideal 4-port antenna. The antenna consists of four elementary Huygens sources operating in Random Line-Of-Sight (RLOS). The antenna is assumed to be wall-mounted. Two specific scenarios for the user distribution are considered, i.e., the 3D hemisphere and a rectangular prism emulating a corridor or a rectangular room. We present simulation results in terms of the cumulative distribution functions corresponding to the resulting polarisation and pattern diversity of 1-bitstream and the corresponding coverage radiation pattern of the 4-port antenna system. We also show that there is an antenna arrangement that maximizes the diversity gain that will be different for different spatial distributions of users.
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| 3. |
- Lehne, Per H., et al.
(författare)
-
Analyzing smart phones' 3D accelerometer measurements to identify typical usage positions in voice mode
- 2016
-
Ingår i: 10th European Conference on Antennas and Propagation, EuCAP 2016; Davos; Switzerland; 10 April 2016 through 15 April 2016. - 2164-3342. - 9788890701863 ; , s. Art. no. 7481895-
-
Konferensbidrag (refereegranskat)abstract
- Smart phone sensors provide new possibilities to understand how devices are actually used and handled in real-life situations. Such information can possibly be used to design better handsets, but also to improve network performance. For example, the radiated performance of a wireless device depends on its orientation and position relative to the user. Hence, knowing realistic handset usage plays a major role in the Over-The-Air characterization of antennas and wireless devices in general. This paper presents an analysis of usage positions for voice service. A simplified statistical model based on data collected from devices acceleration sensors is presented. The analysis shows interesting results from which we can identify some typical ways the user is handling the phone when in a voice conversation. Our analysis shows clear differences of the orientation of the handset when used with a handsfree set and when not.
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| 4. |
- Lehne, Per Hjalmar, et al.
(författare)
-
Measuring user-induced-randomness to evaluate smart phone performance in real envi-ronments
- 2015
-
Ingår i: 9th European Conference on Antennas and Propagation, EuCAP 2015, Lisbon, Portugal, 13-17 May 2015. - 9788890701856
-
Konferensbidrag (refereegranskat)abstract
- The radiated performance of a wireless device depends on its orientation and position relative to the user. In addition, the antenna performance is different on different devices and it depends on the device model. Hence, to understand the impact of the users behaviour on the device antenna and the resulting network performance an investigation of the device usage and signal quality is of high importance. This paper presents a first analysis of the orientation usage of wireless devices based on data gathered from 5 smart phones over a period of more than two months. The data was obtained from the built-in sensors in the phone, and includes angles of orientation, information about signal quality and the connected network Some interesting trends regarding typical orientations of the phone are presented for both voice and data services. We believe that data of this type has the potential to be used for optimizing the device and the network performance, e.g., when the data is correlated with the experienced channel quality.
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| 5. |
- Rahiminejad, Sofia, 1987, et al.
(författare)
-
Design of micromachined ridge gap waveguides for millimeter-wave applications
- 2011
-
Ingår i: Procedia Eng.. - : Elsevier BV. ; 25, s. 519-522
-
Konferensbidrag (refereegranskat)abstract
- The ridge gap waveguide is a new transmission line for millimeter-wave applications. Traditionally, rectangular waveguides are used for those applications due to their low loss. However their fabrication requires precision machining, very good electrical contact and alignment between two joining mechanical parts. Ridge gap waveguides can obtain similar performance without requiring conductive sidewalls and this provides more freedom during the fabrication and assembly process as the structure is no longer sensitive to small gaps between the side walls and the upper lid. The ridge gap waveguide has already been validated for 10-20 GHz using conventional fabrication methods. The ridge gap waveguide prototypes presented in this paper are designed to work in the frequency region between 210 and 340 GHz, and fabricated using MEMS technology. MEMS technology provides fabrication precision of the structures and thus opens the path for high-frequency components.
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| 6. |
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| 7. |
- Rahiminejad, Sofia, 1987, et al.
(författare)
-
Micromachined Ridge Gap Waveguide and Resonator for Millimeter-Wave Applications
- 2012
-
Ingår i: Sensors and Actuators, A: Physical. - : Elsevier BV. - 0924-4247 .- 1873-3069. ; 186, s. 264-269
-
Tidskriftsartikel (refereegranskat)abstract
- The ridge gap waveguide is a fundamentally new high-frequency waveguide. It does not need any electrical contact between the split blocks which gives it an advantage compared to the rectangular waveguide which is the standard today. These waveguides are conventionally fabricated by milling, although above 100 GHz milling is not adequate anymore. MEMS technology on the other hand, can offer high-precision fabrication and thus opens the path for new types of high-frequency components. In this paper both a ridge gap waveguide and a ridge gap resonator have been fabricated for the frequencies 220–325 GHz using MEMS technology. Support packages have been designed to enable device measurements. Simulations show that the reflection coefficient for the ridge gap waveguide is below −15 dB between 240 and 340 GHz. Two resonance peaks were measured at the frequencies 234 GHz and 284 GHz for the ridge gap resonator with unloaded Q-values of 336 and 527 respectively. Both the waveguide and resonator have the potential to obtain similar performances as the rectangular waveguide without strict requirement on electrical contact, allowing simplified fabrication and assembly technique.
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| 8. |
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| 9. |
- Schilliger Kildal, Madeleine, 1987, et al.
(författare)
-
Initial Measured OTA Throughput of 4G LTE Communication to Cars with Roof-Mounted Antennas in 2D Random-LOS
- 2016
-
Ingår i: International Symposium on Antennas and Propagation (ISAP), Hobart, Australia, 9-12 November, 2015. ; , s. Article no 7447419-
-
Konferensbidrag (refereegranskat)abstract
- We present initial Over-The-Air (OTA) throughput measurements of an LTE device in a Volvo XC90 car with roof-mounted antennas. The measurements were performed ina semi-anechoic chamber and only in the horizontal plane. The throughput results are presented as a probability of detection (PoD) in 2D Random Line-Of-Sight (Random-LOS) with fixed polarization of the antenna at the base station side. Two carmounted antennas were measured: a wideband two-port sharkfin type antenna in SISO and SIMO receive diversity-mode, and a narrowband monopole antenna. The PoD curves clearly show the expected performance improvements due to the antenna diversity.In addition, the Random-LOS measurements made it possible to discover potential for improvements of the tested antennas.
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| 10. |
- Schilliger Kildal, Madeleine, 1987, et al.
(författare)
-
Investigation of mode stirring with plate on platform in a reverberation chamber
- 2015
-
Ingår i: 9th European Conference on Antennas and Propagation, EuCAP 2015, Lisbon, Portugal, 13-17 May 2015. - 9788890701856
-
Konferensbidrag (refereegranskat)abstract
- The accuracy of the reverberation chamber has been investigated when mode stirring is performed with a plate placed on a rotatable platform, i.e., plate-on-platform stirring. The accuracy and scanning volume of the platform plate are then compared to the original mode stirring plates that are moving alongside two walls. The results are also compared to physical theoretical models. The mode stirring with a plate on the platform provides STD of the measurements that are a factor 2 worse than with the original plate and platform stirring of the chamber. Still, this is good enough for accurate measurements above 2 GHz, provided the AUT is also located on the platform.
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| 11. |
- Schilliger Kildal, Madeleine, 1987, et al.
(författare)
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Measured LTE throughput for SISO, SIMO and MIMO in Polarization-Random-LOS
- 2016
-
Ingår i: 2016 IEEE International Symposium on Antennas and Propagation (APSURSI). - 9781509028863 ; , s. 323-324
-
Konferensbidrag (refereegranskat)abstract
- LTE throughput measurements in a Random Line-of-Sight (Random-LOS) setup have been performed. The effect of polarization-randomness on the level of detection threshold of one or two bitstreams has been investigated. Good agreement is shown between theory and experiments for the SISO, SIMO and MIMO cases.
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| 12. |
- Schilliger Kildal, Madeleine, 1987, et al.
(författare)
-
Measured probabilities of detection for 1- and 2 bitstreams of 2-port car-roof antenna in RIMP and Random-LOS
- 2016
-
Ingår i: 2016 10th European Conference on Antennas and Propagation (EuCAP). - 9788890701863
-
Konferensbidrag (refereegranskat)abstract
- Autonomous cars will in a near future drive around in cities and on highways. Antennas will then be needed to secure the wireless connection to these cars. To be able to test the antennas we have defined two edge environments: the Random Line-of-Sight (LOS) and the Rich Isotropic Multipath (RIMP). This paper shows a throughput performance comparison between measurements and simulations of a car-roof (shark-fin) antenna mounted on a ground plane in both of these environments. The comparison is done for both one and two bitstreams in a 2×2 MIMO system. The analysis is based on probability of detection (PoD) curves representing the throughput performance with digital threshold receivers.
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| 13. |
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| 14. |
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| 15. |
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| 16. |
- Alfonso Alos, Esperanza, 1979, et al.
(författare)
-
Gap waveguide components for millimeter-wave systems. Couplers, filters, antennas, MMIC packaging
- 2012
-
Ingår i: IEEE Antennas and Propagation Society, AP-S International Symposium (Digest). - 1522-3965. - 9784885522703 ; , s. 243-246
-
Konferensbidrag (refereegranskat)abstract
- Design of passive components (couplers, filters and antennas) and MMIC packaging validation intended for RF front ends for microwave links at 38 GHz using gap waveguide technology have been shown. The use of this technology allows all-in-one integration of receiver, transmitter, and diplexer including the antenna into one mechanical unit. These initial designs and studies have been made at the microwave band for validation and measurement purposes, and for comparison with existing technology. They represent the first step towards the application of gap waveguides to millimeter-wave systems, where gap waveguides could have a large potential.
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| 17. |
- Alfonso Alos, Esperanza, 1979, et al.
(författare)
-
Ka-Band Gap Waveguide Coupled-Resonator Filter for Radio Link Diplexer Application
- 2013
-
Ingår i: IEEE Transactions on Components, Packaging and Manufacturing Technology. - : Institute of Electrical and Electronics Engineers (IEEE). - 2156-3985 .- 2156-3950. ; 3:5, s. 870-879
-
Tidskriftsartikel (refereegranskat)abstract
- Gap waveguide technology represents an interesting alternative as low-loss, cost-effective, and high-performance transmission line and package of microwave and millimeter-wave systems. A Ka-band coupled-resonator filter for a radio link diplexer, which requires high selectivity to isolate transmit and receiving channels, is proposed and realized using gap waveguide technology. The band-pass filter, which has a central frequency of 37.37 GHz and a pass bandwidth of 560 MHz, is fabricated between two parallel metal plates, leaving an air gap between them. After milling one of the plates, silver-plating is applied on them. Measurements show a minimum in-band insertion loss of 1 dB and agree quite well with simulations.
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| 18. |
- Alfonso Alos, Esperanza, 1979, et al.
(författare)
-
Ka-band gap waveguide coupled-resonator filter for radio link diplexers
- 2012
-
Ingår i: XXVII Simposium Nacional de la Unión Científica Internacional de Radio, URSI 2012 (Spanish URSI), Elche, Spain, 12-14 September 2012.
-
Konferensbidrag (refereegranskat)abstract
- Gap waveguide technology represents an interesting alternative as low-loss, cost-effective and high-performance transmission line and package of microwave and millimeter-wave systems. A Ka-band coupled-resonator filter for a radio link diplexer, which requires high selectivity to isolate transmit and receiving channels, is proposed and realized using gap waveguide technology. The band-pass filter, which has a central frequency of 37.37 GHz and a pass bandwidth of 560 MHz, is fabricated between two metal parallel plates leaving an air gap between them. Measurements show a minimum in-band insertion loss of 1 dB and agree quite well with simulations.
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| 19. |
- Alfonso Alos, Esperanza, 1979, et al.
(författare)
-
Parabolic cylindrical reflector antenna at 60 GHz with line feed in gap waveguide technology
- 2013
-
Ingår i: 7th European Conference on Antennas and Propagation, EuCAP 2013, Gothenburg, Sweden, 8-12 April 2013. - 2164-3342. - 9781467321877 ; , s. 319-323
-
Konferensbidrag (refereegranskat)abstract
- A parabolic cylindrical reflector antenna is proposed in this paper for wireless multi-gigabit communications at 60 GHz. The line feed is realized by a power distribution in parallel plate waveguide (PPW). Inside the PPW waveguide there are metal pin rows forming the contours of an H-plane horn structure in front of a parabolic reflector, where we see possible mechanical advantages in not requiring metal contact of the pins to more than one metal plate. They will still work as a total reflecting wall by making use of the same stopband features as in gap waveguide technology. The result is a low loss, low cost and very versatile 60 GHz antenna with high gain. The electrical design for maximum aperture efficiency and minimum loss is explained.
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| 20. |
- Alfonso, E., et al.
(författare)
-
Design of microwave circuits in ridge gap waveguide technology
- 2010
-
Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781424460564 ; , s. 1544 - 1547
-
Konferensbidrag (refereegranskat)abstract
- This paper presents recent advances is a new waveguiding technology referred to as ridge gap waveguides. The main advantages of the ridge gap waveguides compared to hollow waveguides are that they are planar and much cheaper to manufacture, in particular at high frequencies such as for millimeter and submillimeter waves. In these waveguides there are no mechanical joints across which electric currents must float. The gap waveguides have lower losses than microstrip lines, and they are completely shielded by metal so no additional packaging is needed, in contrast to the severe packaging problems associated with microstrip circuits. The gap waveguides are realized in a narrow gap between two parallel metal plates by using a texture on one of the surfaces. The waves follow metal ridges in the textured surface. All wave propagation in other directions is prohibited (in cutoff) by realizing a high impedance (ideally a perfect magnetic conductor) through the textured surface at both sides of all ridges. Thereby, cavity resonances do not appear within the band of operation. The paper studies the characteristic impedance of the line and presents simulations and measurements of circuits designed using this technology.
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| 21. |
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| 22. |
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| 23. |
- Alfonso, E., et al.
(författare)
-
Power divider in ridge gap waveguide technology
- 2010
-
Ingår i: EuCAP 2010 Fourth European Conference on Antennas and Propagation, Barcelona, 12-16 April 2010. - 9781424464319
-
Konferensbidrag (refereegranskat)abstract
- A power divider in ridge gap waveguide technology has been designed to work at 15GHz. Measurements and simulations are provided. Besides, a broad numerical study of the characteristic impedance of a ridge gap waveguide is presented.
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| 24. |
- Alfonso, E., et al.
(författare)
-
Study of the characteristic impedance of a ridge gap waveguide
- 2009
-
Ingår i: IEEE Antennas and Propagation Society, AP-S International Symposium (Digest). - 1522-3965. - 9781424436477
-
Konferensbidrag (refereegranskat)abstract
- This paper presents a study of the characteristic impedance of a ridge gap waveguide. Ridge gap waveguides belongs to a new metamaterial-based waveguide technology for millimeter and submillimeter waves which emerged recently. A formula for the characteristic impedance of an ideal PEC-over-PMC ridge gap waveguide has been derived. A preliminary numerical study of the characteristic impedance of a real ridge gap waveguide where the PMC is realized by a bed of nails is also presented.
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| 25. |
- Algaba Brazalez, Astrid, 1983, et al.
(författare)
-
Design and Validation of Microstrip Gap Waveguides and Their Transitions to Rectangular Waveguide, for Millimeter-Wave Applications
- 2015
-
Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 63:12, s. 4035-4050
-
Tidskriftsartikel (refereegranskat)abstract
- The paper describes the design methodology, experimentalvalidation and practical considerations of two millimeterwave wideband vertical transitions from two gap waveguide versions (inverted microstrip gap waveguide, and microstrip packaged by using gap waveguide) to standard WR-15 rectangular waveguide. The experimental results show S11 smaller than -10 dB over relative bandwidths larger than 25% and 26.6% when Rogers RO3003 and RO4003 materials are used respectively. The vertical transition from standard microstrip line packaged by a lid of pins to WR-15, shows measured return loss better than 15 dB over 13.8% relative bandwidth. The new transitions can be used as interfaces between gap waveguide feed-networks for 60 GHz antenna systems, testing equipment (like Vector Network Analyzers) and components with WR-15 ports, such as transmitting/receiving amplifiers. Moreover, the paper documents the losses of different gap waveguide prototypes compared to unpackaged microstrip line and Substrate Integrated Waveguide (SIW). This investigation shows that in V-band the lowest losses are achieved with inverted microstrip gap waveguide.
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| 26. |
- Algaba Brazalez, Astrid, 1983, et al.
(författare)
-
Design of a coplanar waveguide-to-ridge gap waveguide transition via capacitive coupling
- 2012
-
Ingår i: Proceedings of 6th European Conference on Antennas and Propagation, EuCAP 2012. Prague, 26-30 March 2012. - 9781457709180 ; , s. 3524-3528
-
Konferensbidrag (refereegranskat)abstract
- A transition from Coplanar Waveguide (CPW) via capacitive coupling in order to provide feeding to the so-called Ridge Gap Waveguide (RGW) has been investigated. The main objective of this work is to find a way to facilitate integration of active electronics with the gap waveguide structure and also to do measurements of the components made in gap waveguide technology working around 100 GHz. The transition design and simulation of S parameters for the designed topology is presented.
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| 27. |
- Algaba Brazalez, Astrid, 1983, et al.
(författare)
-
Design of a transition from WR-15 to microstrip packaged by gap waveguide technology
- 2015
-
Ingår i: ISAP 2014 - 2014 International Symposium on Antennas and Propagation, Conference Proceedings, Taiwan, 2-5 December 2014. - 9789869147408 ; , s. 235-236
-
Konferensbidrag (refereegranskat)abstract
- The gap waveguide technology is an advantageous way of packaging passive microstrip components. This work presents a wideband transition from a standard microstrip line packaged by using a bed of nails, to a rectangular waveguide operating in V band. The transition is designed by means of a T-shaped patch that couples the fields into a rectangular waveguide extending vertically from the microstrip circuit. The simulated results show more than 28.5% bandwidth with S11 lower than -10 dB. This transition is intended to be used as a WR-15 port of a planar array antenna for 60 GHz applications, where the array elements are fed by microstrip distribution networks packaged by gap waveguide technology. Thereby, radiation is avoided from the distribution network itself.
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| 28. |
- Algaba Brazalez, Astrid, 1983, et al.
(författare)
-
Design of F-Band Transition From Microstrip to Ridge Gap Waveguide Including Monte Carlo Assembly Tolerance Analysis
- 2016
-
Ingår i: IEEE Transactions on Microwave Theory and Techniques. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9480 .- 1557-9670. ; 64:4, s. 1245-1254
-
Tidskriftsartikel (refereegranskat)abstract
- This paper describes the design and realization of a transition from a microstrip line to a ridge gap waveguide operating between 95 and 115 GHz. The study includes simulations, measurements, and a Monte Carlo analysis of the assembly tolerances. The purpose of this tolerance study is to identify the most critical misalignments that affect the circuit performance and to provide guidelines about the assembly tolerance requirements for the proposed transition design.
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| 29. |
- Algaba Brazalez, Astrid, 1983, et al.
(författare)
-
Design of Millimeter-Wave Wideband Gap Waveguide Transitions Considering Integration into the Antenna System
- 2015
-
Ingår i: 9th European Conference on Antennas and Propagation, EuCAP 2015, Lisbon, Portugal, 13-17 May 2015. - 9788890701856
-
Konferensbidrag (refereegranskat)abstract
- Two wideband vertical transitions from inverted microstrip gap waveguide to rectangular waveguide (WR-15) for 60 GHz antenna array applications are proposed. Thesetransitions are aimed to interconnect the WR-15 with the gap waveguide feed-network employed to provide feeding to the radiating elements of slot/horn antenna arrays. The wideband field transformation is achieved without the need of adding a quarter-wavelength cavity backshort on a metal block placed over the transition. First, we replace this backshort by creating a cavity in the radiating layer when this is made in Substrate Integrated Waveguide (SIW) technology, and thereafter we use an air-filled pin cavity in the radiating layer. The simulated Sparametersshow that the presented transitions cover the unlicensed 60 GHz band (57-64 GHz) with good margins.
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| 30. |
- Algaba Brazalez, Astrid, 1983, et al.
(författare)
-
Evaluation of losses of the ridge gap waveguide at 100 GHz
- 2013
-
Ingår i: IEEE Antennas and Propagation Society, AP-S International Symposium (Digest). - 1522-3965. - 9781467353175 ; , s. 1456-1457
-
Konferensbidrag (refereegranskat)abstract
- An evaluation of losses of the Ridge Gap Waveguide (r-GAP) at 100 GHz has been developed in terms of Quality Factor. For this aim, an r-GAP resonator has been designed, simulated and measured. The feeding to the circuit is provided via a transition from Micostrip-to-Ridge Gap Waveguide based in electromagnetic coupling in order to ensure compatibility with the available probe stations.
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| 31. |
- Algaba Brazalez, Astrid, 1983, et al.
(författare)
-
Improved Microstrip Filters Using PMC Packaging by Lid of Nails
- 2012
-
Ingår i: IEEE Transactions on Components, Packaging and Manufacturing Technology. - 2156-3985 .- 2156-3950. ; 2:7, s. 1075-1084
-
Tidskriftsartikel (refereegranskat)abstract
- This paper shows that microstrip filters perform like textbook examples when packaged with perfect magnetic conductor (PMC). A PMC is made as a pin surface or lid of nails, and this is used to package a microstrip parallel coupled line bandpass filter. Our measurements confirm that parallel plate, cavity modes, and radiation are suppressed. This paper also includes a study of the reasons for a frequency shift between the ideal PMC packaged case and the realized case.
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| 32. |
- Algaba Brazalez, Astrid, 1983, et al.
(författare)
-
Improving microstrip filters with gap waveguide packaging
- 2011
-
Ingår i: Proceedings of the 5th European Conference on Antennas and Propagation, EUCAP 2011. Rome, 11-15 April 2011. - 9781457702501 ; , s. 1080-1084
-
Konferensbidrag (refereegranskat)abstract
- A study is presented of the performance of microstrip filters packaged with Perfect Magnetic Conductor (PMC) and realization of the PMC using a lid of nails. A 3rd order parallel coupled-line bandpass filter is designed and packaged with a lid of nails at the Ku-band. The study shows the PMC packaging technique is very efficient in improving the filter characteristics including the insertion loss in the bandpass region.
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| 33. |
- Algaba Brazalez, Astrid, 1983, et al.
(författare)
-
Investigation of a Microstrip-to-Ridge Gap Waveguide transition by electromagnetic coupling
- 2012
-
Ingår i: IEEE Antennas and Propagation Society, AP-S International Symposium (Digest). - 1522-3965. - 9781467304627 ; , s. 1-2
-
Konferensbidrag (refereegranskat)abstract
- A transition from Microstrip to Ridge Gap Waveguide (RGW) has been studied and numerically analyzed in terms of S parameters. The RGW technology shows potential to be used up to THz frequencies. Therefore, good transitions are needed in order to make possible the measurements of RGW components at frequencies above 100 GHz.
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| 34. |
- Algaba Brazalez, Astrid, 1983, et al.
(författare)
-
Investigation of Transitions for Use in Inverted Microstrip Gap Waveguide Antenna Arrays
- 2014
-
Ingår i: 8th European Conference on Antennas and Propagation, EuCAP 2014, The Hague, The Netherlands 6-11 April 2014. - 9788890701849 ; , s. 995 - 999
-
Konferensbidrag (refereegranskat)abstract
- The main purpose of this work is to create good transitions for inverted microstrip-based versions of gap waveguide that are used to feed slot or horn antenna arrays. Two new millimeter-wave transitions from inverted microstrip gap waveguide to rectangular waveguide are presented. Both geometries are similar and consist of a planar probe, which contains a rectangular patch or T-section. The planar probe is inserted inside the rectangular waveguide through an opening made in the broadside wall of the waveguide. The main difference between the two geometries is that one of them extends upwards and the other one downwards with respect to the planar inverted microstrip gap waveguide circuit. The simulated S-parameters show promising results.
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| 35. |
- Aljarosha, Alhassan, 1982, et al.
(författare)
-
Mm-Wave contactless connection for MMIC integration in gap waveguides
- 2016
-
Ingår i: 2016 IEEE Antennas and Propagation Society International Symposium, APSURSI 2016, Fajardo, Puerto Rico, 26 June - 1 July 2016. - 1522-3965. ; , s. 253-254
-
Konferensbidrag (refereegranskat)abstract
- A contactless, broadband and low-loss microstrip-to-groove gap waveguide transition operating at W-band is presented. The principle of operation is based on transforming EM fields from the SIW to the ridge gap waveguide mode via electromagnetic coupling. This is advantageous, since the proposed solution avoids the use of metal contact between the SIW and one of the waveguide parts. Furthermore, metamaterial-based gap waveguide technology provides a resonance-free packaging solution.
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| 36. |
- Andersson, Mats, et al.
(författare)
-
Three Fast Ways of Measuring Receiver Sensitivity in a Reverberation Chamber
- 2008
-
Ingår i: 2008 IEEE International Workshop on Antenna Technology: Small Antennas and Novel Metamaterials, IWAT 2008; Chiba; Japan; 4 March 2008 through 6 March 2008. ; , s. 51-54
-
Konferensbidrag (refereegranskat)abstract
- The traditional way of evaluating receiver sensitivity is to measure the Total Isotropic Sensitivity (TIS) in an anechoic environment. Very few wireless terminals with small antennas are used in an anechoic environment. This paper will describe three alternative methods to measure the receiver sensitivity in a reverberation chamber, each of which can be done in less than 10 minutes which is much faster than measurements in anechoic chamber. The fastest method is the average fading sensitivity AFS that in contrast to TIS also be used to measure receiver sensitivity of multi antenna terminals for antenna systems with diversity and MIMO capability. The paper includes the first published TIS and AFS results for WCDMA terminals obtained in a reverberation chamber. The agreement to TIS measurements in anechoic chambers is shown to be good.
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| 37. |
- Azremi, A.A.H., et al.
(författare)
-
On diversity performance of two-element coupling element based antenna structure for mobile terminal
- 2010
-
Ingår i: EuCAP 2010 Fourth European Conference on Antennas and Propagation, Barcelona, 12-16 April 2010.
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Konferensbidrag (refereegranskat)abstract
- In wireless communication systems, multipath interference has a significant impact on system design and performance. Fast fading is caused by the coherent summation of one or more echoes from many reflection points reaching the receive antenna. Antenna diversity can be used to mitigate multipath fading. The main challenge of antenna diversity in practical application is the integration of multiple antennas on a small ground plane. Two-element antenna structure based on coupling element antenna concept for diversity application has been studied in previous work and it has shown to be feasible for low frequency diversity application with stable and low envelope correlation across wide frequency range. The studied structure has been tuned to be operating at 1600 MHz for measurement evaluation purpose. This paper presents an analysis of diversity performance of the structure in terms of efficiencies, envelope correlation, and apparent and effective diversity gains in isotropic (i.e. statistically uniform) propagation channel, using spherical near-field technique in an ideal line-of-sight environment (anechoic chamber) and inside reverberation chamber. The envelope correlation is less than 0.1 and the diversity gain is equal to 10.2 dB at 99% reliability level using selection combining technique across simulation and both measurement methods. The measurement techniques are compared to show how accurately the diversity performance of a mobile terminal antenna can be estimated.
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| 38. |
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| 39. |
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| 40. |
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| 41. |
- Bosiljevac, M., et al.
(författare)
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Analytical modeling and experimental verification of coupling between transmission lines in gap-waveguides
- 2012
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Ingår i: Proceedings of 6th European Conference on Antennas and Propagation, EuCAP 2012. Prague, 26-30 March 2012. - 9781457709180 ; , s. 1402-1406
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Konferensbidrag (refereegranskat)abstract
- Modeling of gap-waveguide structures with single and multiple transmission lines is performed using spectral domain Green's functions approach. The approach is extended using even/odd mode analysis in order to also estimate the crosstalk levels between neighboring transmission lines. The results of this analysis are compared with the results of a commercial electromagnetic solver and with the measured results.
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| 42. |
- Bosiljevac, M., et al.
(författare)
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Construction of Green's functions of parallel plates with periodic texture with application to gap waveguides - A plane wave spectral domain approach
- 2010
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Ingår i: IET Microwaves, Antennas and Propagation. - : Institution of Engineering and Technology (IET). - 1751-8725 .- 1751-8733. ; 4:11, s. 1799-1810
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Tidskriftsartikel (refereegranskat)abstract
- This study presents Green's functions of parallel-plate structures, where one plate has a smooth conducting surface and the other an artificial surface realised by a one-dimensional or two-dimensional periodic metamaterial-type texture. The purpose of the periodic texture is to provide cut-off of the lowest order parallel-plate modes, thereby forcing electromagnetic energy to follow conducting ridges or strips, that is, to form a gap waveguide as recently introduced. The Green's functions are constructed by using the appropriate homogenised ideal or asymptotic boundary conditions in the plane-wave spectral domain, thereby avoiding the complexity of the Floquet-mode expansions. In the special case of a single ridge or strip, an additional numerical search for propagation constants is needed and performed in order to satisfy the boundary condition on the considered ridge or strip in the spatial domain. The results reveal the dispersion characteristics of the quasi-transverse electromagnetic modes that propagate along the ridges or strips, including their lower and upper cut-off frequencies, as well as the theoretical decay of the modal field in the transverse cut-off direction. This lateral decay shows values of 50-100 dB per wavelength for realisable geometries, indicating that the gap waveguide modes are extremely confined. The analytical formulas for the location of the stopband of the lowest order parallel-plate modes obtained by small-argument approximation of the dispersion equation are also shown. To verify the proposed analysis approach, the results are compared with the results obtained with a general electromagnetic solver showing very good agreement.
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| 43. |
- Bosiljevac, M., et al.
(författare)
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Efficient spectral domain Green's function analysis of novel metamaterial bandgap guiding structures
- 2010
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Ingår i: EuCAP 2010 Fourth European Conference on Antennas and Propagation, Barcelona, 12-16 April 2010. - 9781424464319
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Konferensbidrag (refereegranskat)abstract
- The Green's function analysis of oversized waveguides with one wall realized as a periodic structure is presented in this paper. Two different realizations of the periodic structures were considered: the bed-of-nails surface and the mushroom surface. Since the period of these surfaces is small compared to wavelength it is possible to take advantage of the asymptotic boundary conditions in the derivation of the required Green's functions. By doing so, we avoid the usual Floquet mode approach needed in the analysis of periodic surfaces and significantly reduce the overall numerical complexity. The Green's functions developed in this way allow dispersion and electromagnetic field analysis since their poles correspond to surface wave modes and waveguide modes. These results reveal the dispersion characteristics of the observed structures and the bandwidth usable in the waveguide applications. The computed results are compared with the results obtained with a general electromagnetic solver and the agreement is very good.
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| 44. |
- Bosiljevac, Marko, et al.
(författare)
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Modelling EBG surfaces using amended DB boundary conditions
- 2011
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Ingår i: European Conference on Antennas and Propagation 2011, 11-15 April 2011, Rome.
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Konferensbidrag (refereegranskat)abstract
- Recently the so-called DB boundary conditions were introduced that exhibit characteristics similar to that of an isotropic soft surface, except for an anomaly at normal incidence. This anomaly has also been amended, and the amended DB boundary condition has been shown to represent reflection from an EBG surface within the bandgap. The present paper summarizes the calculated characteristics of a practical planar EBG surface when modelled both with CST and the homogenous PMC-amended DB boundary condition. The paper also shows that the surface of an anistrotropic material with zero eps_z and mu_z will behave similar to the original DB boundary condition, and this is used to understand the anomaly for normal incidence by studying the case of eps_z and mu_z approaching zero.
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| 45. |
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| 46. |
- Bosiljevac, M., et al.
(författare)
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Simple Boundary Condition for Canonical EBG Surface: PMC-Backed Uniaxial Medium
- 2016
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Ingår i: IEEE Transactions on Antennas and Propagation. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-926X .- 1558-2221. ; 64:2, s. 785-U550
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Tidskriftsartikel (refereegranskat)abstract
- A simple-to-use replacement model for isotropic electromagnetic bandgap (EBG) surfaces such as mushroom surfaces is investigated. Properties of EBG surfaces strongly depend on the incidence angle of the incoming plane wave. The suggested model takes this behavior into account and actually represents the ideal EBG surface. The model is based on uniaxial representation of a thin DB layer backed by a perfect magnetic conductor (PMC) plate. We investigate how this model behaves in comparison with a realistic mushroom surface, and when it can be applied. The results show that the proposed model can be used for both far field calculations and antenna coupling evaluation.
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| 47. |
- Bourhis, R., et al.
(författare)
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Measurements of realized diversity gain of active DECT phones and base-stations in a reverberation chamber
- 2004
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Ingår i: IEEE Antennas and Propagation Society Symposium 2004 Digest held in Conjunction with: USNC/URSI National Radio Science Meeting; Monterey, CA; United States; 20 June 2004 through 25 June 2004. - : IEEE. - 0272-4693. ; 1, s. 715-718
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Konferensbidrag (refereegranskat)abstract
- The purpose of this paper is to present different setups to measure the diversity gain of active DECT phones and base-stations by use of a reverberation chamber, when the integrated software in the device provides the diversity combination. After the description of the setups, the main results of the validation tests will be presented, as well as the results of the final measurements on commercial devices.
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| 48. |
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