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Beckman, Claes
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Publications (10 of 21) Show all publications
Ramachandran, P., Milosavljevic, Z. & Beckman, C. (2012). Adaptive penta-band handset antenna with hand effect compensation. IET Microwaves, Antennas & Propagation, 6(1), 79-86
Open this publication in new window or tab >>Adaptive penta-band handset antenna with hand effect compensation
2012 (English)In: IET Microwaves, Antennas & Propagation, ISSN 1751-8725, E-ISSN 1751-8733, Vol. 6, no 1, p. 79-86Article in journal (Refereed) Published
Abstract [en]

The increase in the number of cellular operating bands and the ever-increasing criteria antenna size reduction has pushed the need to use switchable antenna structures. Further, the presence of a hand in the close vicinity of the antenna causes deterioration in performance. The authors present a switchable antenna technique, evaluate the effect of the human hand on it and discuss a novel method to compensate for the mismatch. A penta-band switchable planar inverted-F antenna covering 824-960 and 1710-2170-MHz has been used in this study. The presence of the hand was observed to cause 2.0-6.0-dB loss in efficiency for the low band. Using the proposed extra-ground antenna switching method and the dynamic antenna matching, technique the total efficiency of the antenna can be improved by 0.5-2.5-dB compared to the mismatched case.

National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:hig:diva-11630 (URN)10.1049/iet-map.2010.0529 (DOI)000300841400011 ()2-s2.0-84857551245 (Scopus ID)
Available from: 2012-06-15 Created: 2012-03-19 Last updated: 2018-03-13Bibliographically approved
Ikram, A., Beckman, C. & Irmscher, S. (2011). Design and Development of a Multiband Loop Antenna for Cellular Mobile Handsets. In: IEEE International Workshop on Antenna Technology: . Paper presented at iWAT 2011, the IEEE International Workshop on Antenna Technology, 7-9 March 2011, Hong Kong (pp. 251-254).
Open this publication in new window or tab >>Design and Development of a Multiband Loop Antenna for Cellular Mobile Handsets
2011 (English)In: IEEE International Workshop on Antenna Technology, 2011, p. 251-254Conference paper, Published paper (Refereed)
Abstract [en]

This paper presents the results of the design and characterization of a loop antenna for mobile cellularh andsets. Based on a typical smart phone antenna geometry, a bottom mounted off-ground meanderline loop antennah as been designed, which has the potential to cover the required bands of Long Term Evolution (LTE) US 700MHz, Global System for Mobile communications (GSM) 824-960MHz, Digital Communication System (DCS) 1710-1880 MHz, Personal Communication Services PCS 1850-1990 MHz, Universal Mobile Telecommunications System (UMTS) 1920-2170MHz and LTE EU 2500. The carrier volume of 50*10*5mm3 and ground plane of length 100mm is used. The carrier permittivity εr is 2.66 and loss tangent tanδ is 0.00629 @2.44GHz. Copper is used as a metal part of the antenna having conductivity of 5.8e7 S/m and thickness of 0.1mm. The antenna supports balanced and unbalanced modes for certain frequencies. It is highly efficient in terms of small volumetric size for a given bandwidth of operations. The antenna generates weak near field electric and magnetic fields complying with the standards for the Specific Absorption Rate (SAR) and Hearing Aid Compability (HAC). The impact of body effects on the radiation efficiency has been quantified. The measured results of the prototype are in good agreement with the simulated results.

National Category
Telecommunications
Identifiers
urn:nbn:se:hig:diva-8597 (URN)10.1109/IWAT.2011.5752321 (DOI)2-s2.0-79957911685 (Scopus ID)978-1-4244-9133-9 (ISBN)
Conference
iWAT 2011, the IEEE International Workshop on Antenna Technology, 7-9 March 2011, Hong Kong
Available from: 2011-03-21 Created: 2011-03-21 Last updated: 2018-03-13Bibliographically approved
Beckman, C. (2011). Verifying 3G License Coverage Requirements. In: Miguel Almeida (Ed.), Advances in Vehicular Networking Technologies (pp. 339-356). InTech
Open this publication in new window or tab >>Verifying 3G License Coverage Requirements
2011 (English)In: Advances in Vehicular Networking Technologies / [ed] Miguel Almeida, InTech , 2011, p. 339-356Chapter in book (Other academic)
Abstract [en]

In the beginning of the 21’st century, the 3rd generation mobile phone systems, 3G, were introduced all around the world. In most countries, spectrum for this technology was allocated through some kind of licensing procedure. In Europe, the prevailing approach was to allocatespectrum through auctions, a process which led to a situation where the European operators found themselves committed to pay a staggering 130Bilion Euros for their 3G licenses.However, in most European countries, the fee was not the only obligation put on thelicensee: A coverage, “roll-out” requirement was in many cases also connected to the license(Northstream, 2002). Typically, these coverage requirements required that the licenseescover a certain area at a certain point in time after that the licenses had been awarded.In order for the regulators to verify that the licensees had met the coverage requirement and,hence, complied with the regulation, a method for coverage verification was needed. Suchmethods have therefore since then been developed by several European regulators (e.g. PTS2004; ECC 2007). In this book chapter we describe some general underlying consideration for the verification of radio coverage in UMTS systems and in particular we describe the Swedishmethodology developed by the Swedish Telecom regulator Post & Telestyrelsen (PTS).

Place, publisher, year, edition, pages
InTech, 2011
Identifiers
urn:nbn:se:hig:diva-9870 (URN)978-953-307-241-8 (ISBN)
Available from: 2011-08-19 Created: 2011-08-19 Last updated: 2018-03-13Bibliographically approved
Prasad, S. & Beckman, C. (2010). Comparison of Four Different Methods to Estimate the Radiated Power from Mobile Phones. In: 2010 Loughborough Antennas and Propagation Conference, LAPC 2010: . Paper presented at 6th Loughborough Antennas and Propagation Conference, LAPC 2010, 8-9 November, 2010, Loughborough United Kingdom (pp. 425-428). , Article ID 5666216.
Open this publication in new window or tab >>Comparison of Four Different Methods to Estimate the Radiated Power from Mobile Phones
2010 (English)In: 2010 Loughborough Antennas and Propagation Conference, LAPC 2010, 2010, p. 425-428, article id 5666216Conference paper, Published paper (Other academic)
Abstract [en]

In this paper, the radiated power is estimated for various commercially available mobile phones using the Telia Scattered Field Measurement method (TSFM), In-Network performance estimation and the EMSCAN near field scanner: "Lab-Express". The results are then compared with the radiated power measured using the Satimo Star Gate 64/24 system. Our measurement results suggest that the radiated power measured in the TSFM method correlates to a great extent both with the Star Gate System and the In-network method suggesting that the TSFM method can be used an alternative tool to in-network measurements and also can be used for standard reference measurements provided accuracy and repeatability are accounted according to the standards. However, the results from the Star Gate system were weakly correlated to the results from the Lab-Express suggesting that Lab-Express cannot replace Star Gate System for standard reference measurements but can only serve as a good tool for testing antennas during design and development phases.

Keywords
Radiated power, mobile phones, In-network, measurements
National Category
Signal Processing Telecommunications
Identifiers
urn:nbn:se:hig:diva-7459 (URN)10.1109/LAPC.2010.5666216 (DOI)2-s2.0-78651442158 (Scopus ID)978-142447305-2 (ISBN)
Conference
6th Loughborough Antennas and Propagation Conference, LAPC 2010, 8-9 November, 2010, Loughborough United Kingdom
Available from: 2010-09-03 Created: 2010-09-03 Last updated: 2018-03-13Bibliographically approved
Andersson, D., Wallin, K., Javashvili, O. & Beckman, C. (2010). M-Sequence UWB Radar for Industrial Applications. In: Program of GigaHertz Symposium 2010, March 9-10, at Lund University: .
Open this publication in new window or tab >>M-Sequence UWB Radar for Industrial Applications
2010 (English)In: Program of GigaHertz Symposium 2010, March 9-10, at Lund University, 2010Conference paper, Published paper (Other academic)
Abstract [en]

Ultra Wideband Radar has the potential of dramatically improving the control and surveillance of industrial processes in confined areas. An example is the application of UWB radar for surveillance of furnaces for heath treatment of steel billets developed by Radarbolaget in Gävle.

In our installation at AB Sandvik Materials Technology, we have shown that by using a non-destructive UWB Radar technique it is possible to visualize in real-time the ongoing process inside the furnace behind a 0.5 m thick ceramic wall. Since the operating temperature inside the furnace is 1200 °C, there is today no other known method capable of visualizing the process for the operator of the furnace. The system is therefore designed to sustain high temperatures and powerful electromagnetic disturbances while performing measurement with wide dynamics and high stability.

The design of this radar is based on the idea of transmitting a continuous m-sequence and then detecting the correlated impulse response (see figure below). The wide bandwidth is a requirement for obtaining high spatial accuracy and resolution but puts further requirements on the design of the antennas and the electronics. Our results show that with this technique it is possible to determine the deformation of the steel billets inside the furnace with an accuracy of less than 5 mm. The radar system is also able to detect deformations in the furnace wall

The m-sequence radar has many advantages over other UWB radar technologies since it e.g. does not require many analogue components. Its performance is a result of the choice of code length, sampling rate and averaging. However, the resolution is still limited by the impulse response of the analogue antenna (ringing).

In this paper system parameters that affect the overall performance of an m-sequence radar are reviewed and means of enhancing its performance are discussed.

National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:hig:diva-6536 (URN)
Available from: 2010-03-23 Created: 2010-03-14 Last updated: 2018-03-13Bibliographically approved
Ramachandran, P., Milosavljevic, Z. & Beckman, C. (2009). Adaptive Matching Circuitry for Compensation of Finger Effect on Handset Antennas. In: EuCAP 2009: 3rd European Conference on Antennas and Propagation (pp. 801-804). Berlin
Open this publication in new window or tab >>Adaptive Matching Circuitry for Compensation of Finger Effect on Handset Antennas
2009 (English)In: EuCAP 2009: 3rd European Conference on Antennas and Propagation, Berlin, 2009, p. 801-804Conference paper, Published paper (Refereed)
Abstract [en]

In this paper we present and evaluate the effect of hand on terminal antenna and discuss a method to compensate for the mismatch. A dual band PIFA was used in this study. The presence of the hand was observed to cause 2-6dB loss in efficiency in low-band and 2-4dB loss in highband.In this study we propose a dynamic antenna matching (DAM) technique to improve matching level that can improve the total efficiency of the antenna by 2 – 4dB compared to the mismatched case.

Place, publisher, year, edition, pages
Berlin: , 2009
Keywords
Dynamic Antenna Match, Terminal Antenna, Total Efficiency, Mismatch
Identifiers
urn:nbn:se:hig:diva-4038 (URN)
Available from: 2009-04-29 Created: 2009-03-31 Last updated: 2018-03-13Bibliographically approved
Zhao, H., Lin, G. & Claes, B. (2009). Design of a Coupling Element Based Penta-band Mobile Phone Antenna. In:  Antennas & Propagation Conference, 2009. LAPC 2009. Loughborough . Paper presented at 2009 Loughborough Antennas \& Propagation Conference (pp. 209-212).
Open this publication in new window or tab >>Design of a Coupling Element Based Penta-band Mobile Phone Antenna
2009 (English)In:  Antennas & Propagation Conference, 2009. LAPC 2009. Loughborough, 2009, p. 209-212Conference paper, Published paper (Refereed)
Abstract [en]

Based on the work by Vilanen et al., a small, low profile and efficientcoupling element based antenna with penta-band operations for the use inmobile telephones has been studied. The antenna was designed using the HighFrequency Structure Simulator, HFSS, from Ansoft. Two prototypes withdifferent antenna profile heights have been built, verified and tested. Thebandwidth of the antenna is extended compared to the original design. Alumped element based network is used to optimize the matching. Theresulting antenna operates (|S11|≤-5 dB) from 824 to 1300MHz and from1710 to 2170MHz, covering in total five cellular bands with an efficiencybetter than -3dB and a total volume of less than 4cm3.

Keywords
Compact mobile antenna, chassis, coupling elements, matching circuit
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:hig:diva-5150 (URN)10.1109/LAPC.2009.5352437 (DOI)978-4244-2720-8 (ISBN)
Conference
2009 Loughborough Antennas \& Propagation Conference
Available from: 2009-11-22 Created: 2009-08-30 Last updated: 2018-03-13Bibliographically approved
Beckman, C. & Klahr, S. (2009). Ett ödesval för regionen. Gefle Dagblad, 6 februari
Open this publication in new window or tab >>Ett ödesval för regionen
2009 (Swedish)In: Gefle Dagblad, Vol. 6 februariArticle in journal (Other (popular science, discussion, etc.)) Published
Identifiers
urn:nbn:se:hig:diva-3728 (URN)
Available from: 2009-03-20 Created: 2009-02-10 Last updated: 2018-03-13Bibliographically approved
Ramachandran , P., Bengtsson , O. & Beckman, C. (2009). Impedance determination of terminal power amplifiers for optimal antenna matching using load-pull method. In: 2009 IEEE International Workshop on Antenna Technology: iWAT2009 : "Small Antennas and Novel Metamaterials". Santa Monica, California
Open this publication in new window or tab >>Impedance determination of terminal power amplifiers for optimal antenna matching using load-pull method
2009 (English)In: 2009 IEEE International Workshop on Antenna Technology: iWAT2009 : "Small Antennas and Novel Metamaterials", Santa Monica, California, 2009Conference paper, Published paper (Refereed)
Abstract [en]

In this paper we present a single tuner based load-pull method for characterization of optimal antenna load impedance in mobile terminals. In the proposed load-pull set-up the mobile terminal itself is used as a source. The presented method can provide valuable data for antenna design since it determines the optimal impedance at the antenna connector/pad taken into account the full output circuitry of the mobile terminal. It reveals the modification of the power amplifier, PA, output impedance caused by the presence of saw filter, antenna switch, and transmission line possibly present between the PA and the antenna. With the presented method it is not only possible to characterize the optimum antenna impedance to present to the terminal in different bands and channels but also to reveal the impedance miss-match sensitivity for each channel.

Place, publisher, year, edition, pages
Santa Monica, California: , 2009
Identifiers
urn:nbn:se:hig:diva-4039 (URN)
Note
2009 IEEE International Workshop on Antenna Technology: iWAT2009 : "Small Antennas and Novel Metamaterials", March 2–4, 2009, Santa Monica, California Available from: 2009-04-29 Created: 2009-03-31 Last updated: 2018-03-13Bibliographically approved
Händel, P., Prasad, S. & Beckman, C. (2009). Maximum likelihood estimation of reverberation chamber direct-to-scattered ratio [Letter to the editor]. Electronics Letters, 45(25), 1285-1286
Open this publication in new window or tab >>Maximum likelihood estimation of reverberation chamber direct-to-scattered ratio
2009 (English)In: Electronics Letters, ISSN 0013-5194, E-ISSN 1350-911X, Vol. 45, no 25, p. 1285-1286Article in journal, Letter (Refereed) Published
Abstract [en]

The exact maximum likelihood estimator of the direct-to-scattered ratio of the Rician channel in a reverberation chamber is derived and its performance analysed. It is shown that the estimator obeys a non-central F-distribution, the mean value and variance of which are derived. For well stirred chambers, it is shown that the systematic error in the estimated ratio may be significant.

Keywords
Reverberation chamber, Maximum Likelihood Estimator, Direct-to-Scattered ratio
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:hig:diva-6018 (URN)10.1049/el.2009.2489 (DOI)000273043100009 ()2-s2.0-72249095057 (Scopus ID)
Available from: 2009-12-17 Created: 2009-12-17 Last updated: 2018-11-26Bibliographically approved
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