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Owais, Owais
Publications (10 of 21) Show all publications
Mohsin, I., Karlsson, M., Owais, O. & Gong, S. (2013). Design and implementation of a UWB six-port correlator for 6-9 GHz frequency band. Microwave and optical technology letters (Print), 55(1), 190-193
Open this publication in new window or tab >>Design and implementation of a UWB six-port correlator for 6-9 GHz frequency band
2013 (English)In: Microwave and optical technology letters (Print), ISSN 0895-2477, E-ISSN 1098-2760, Vol. 55, no 1, p. 190-193Article in journal (Refereed) Published
Abstract [en]

A compact size six-port correlator using bandwidth enhancing stubs for the 69 GHz ultra wideband radio is presented. The proposed six-port has a center frequency of 7.5 GHz with 50% relative bandwidth. The correlator is based entirely on microstrip technology for low cost and simple circuit implementation.

Place, publisher, year, edition, pages
Wiley-Blackwell, 2013
Keywords
branch line coupler; six-port correlator; ultra wideband; microstrip technology; miniaturization
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-87198 (URN)10.1002/mop.27235 (DOI)000311386700049 ()
Available from: 2013-01-14 Created: 2013-01-14 Last updated: 2019-09-19
Karlsson, M., Serban, A., Östh, J., Owais, O. & Gong, S. (2013). Frequency Triplexer for Ultra-Wideband Systems (6–9 GHz). IEEE Transactions on Circuits and Systems Part 1: Regular Papers, 60(3), 540-547
Open this publication in new window or tab >>Frequency Triplexer for Ultra-Wideband Systems (6–9 GHz)
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2013 (English)In: IEEE Transactions on Circuits and Systems Part 1: Regular Papers, ISSN 1549-8328, E-ISSN 1558-0806, Vol. 60, no 3, p. 540-547Article in journal (Refereed) Published
Abstract [en]

A triplexer for ultra-wideband radio implemented entirely with distributed microstrips is presented. The triplexer is composed of a triplex junction network and three bandpass filters. The circuit is integrated in a flex-rigid printed circuit board. Three flat 1 GHz sub-bands in the frequency band 6-9 GHz have been achieved. The group delay variation within each 1 GHz sub-band was measured to be less than 0.4 ns. A good agreement between simulation and measurement was obtained, e.g., less than 0.3 dB difference in the forward transmission in the majority of the frequency band.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2013
Keywords
Bandpass filter, broadside-coupled, edge-coupled, frequency multiplexing, triplexer, UWB
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-90756 (URN)10.1109/TCSI.2012.2215743 (DOI)000315959100003 ()
Note

Funding Agencies|Sony Mobile Communications AB||Ericsson AB||Vinnova in Sweden||

Available from: 2013-04-08 Created: 2013-04-05 Last updated: 2019-06-17Bibliographically approved
Östh, J., Karlsson, M., Owais, O., Serban, A. & Gong, S. (2012). Baseband complexity comparison of six-, five-, and four-port receivers. Microwave and optical technology letters (Print), 54(6), 1502-1506
Open this publication in new window or tab >>Baseband complexity comparison of six-, five-, and four-port receivers
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2012 (English)In: Microwave and optical technology letters (Print), ISSN 0895-2477, E-ISSN 1098-2760, Vol. 54, no 6, p. 1502-1506Article in journal (Refereed) Published
Abstract [en]

The use of six-port correlators to implement six-port receivers has been intensively studied. The six-port receiver can also be modified to a five-port or a four-port receiver. However, the six-, five-, or four-port receiver solution requires different baseband processing to recover the baseband In-phase (I) and Quadrature-phase (Q) data. A unified mathematical model for the six-, five- and four-port receivers is presented in this article. Possible solutions to recover the baseband data are discussed and compared. The investigation shows that the six-port receiver has advantages over the five- and four-port receivers in terms of complexity when analog baseband processing is used. Simulations are conducted to verify the model and to estimate the error vector magnitude versus frequency; the simulation also shows that the six-port receiver operates over a wider bandwidth than the five- or four-port receiver.

Place, publisher, year, edition, pages
Wiley-Blackwell, 2012
Keywords
six-port receiver, five-port receiver, four-port receiver, baseband complexity
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-76606 (URN)10.1002/mop.26833 (DOI)000301715800045 ()
Available from: 2012-04-13 Created: 2012-04-13 Last updated: 2019-06-17
Owais, O., Östh, J. & Gong, S. (2011). Differential Six-Port Demodulator. In: Proceedings on International Conference on Wireless Communications and Signal Processing. Paper presented at International Conference on Wireless Communications and Signal Processing (WSPS2011), 9-11 November, Nanjing, China.
Open this publication in new window or tab >>Differential Six-Port Demodulator
2011 (English)In: Proceedings on International Conference on Wireless Communications and Signal Processing, 2011Conference paper, Published paper (Other academic)
Abstract [en]

A differential six-port demodulator for the 7-8 GHz band is reported for the first time. It is composed of a differential six-port correlator on the two sides of the substrate and zero-bias antiparallel Schottky diodes acting as power detectors. It is theoretically analyzed and also simulated. A prototype has been fabricated and data transmission at 0.8 Gbit/s (but not the maximum) with the 16 quadrature amplitude modulation (QAM) is experimentally demonstrated.

Keywords
differential; six-port; direct conversion demodulator; antiparallel diode pair
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-71834 (URN)
Conference
International Conference on Wireless Communications and Signal Processing (WSPS2011), 9-11 November, Nanjing, China
Available from: 2011-11-07 Created: 2011-11-07 Last updated: 2011-11-07Bibliographically approved
Owais, O., Östh, J., Serban, A., Karlsson, M. & Gong, S. (2011). Differential Six-Port Demodulator. Microwave and optical technology letters (Print), 53(9), 2192-2197
Open this publication in new window or tab >>Differential Six-Port Demodulator
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2011 (English)In: Microwave and optical technology letters (Print), ISSN 0895-2477, E-ISSN 1098-2760, Vol. 53, no 9, p. 2192-2197Article in journal (Refereed) Published
Abstract [en]

A differential six-port demodulator for the 7-8 GHz band is reported for the first time. It is composed of a differential six-port correlator on the two sides of the substrate and zero-bias antiparallel Schottky diodes acting as power detectors. It is theoretically analyzed and also simulated. A prototype has been fabricated and data transmission at 0.8 Gbit/s (but not the maximum) with the 16 quadrature amplitude modulation (QAM) is experimentally demonstrated.

Place, publisher, year, edition, pages
John Wiley and Sons, Ltd, 2011
Keywords
differential; six-port; direct conversion demodulator; antiparallel diode pair
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-69769 (URN)10.1002/mop.26191 (DOI)000292600900066 ()
Available from: 2011-08-10 Created: 2011-08-08 Last updated: 2019-06-17Bibliographically approved
Owais, O. (2011). Differential Six-port Radio Transceiver for Ultra-wideband and Wideband Antennas. (Doctoral dissertation). Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Differential Six-port Radio Transceiver for Ultra-wideband and Wideband Antennas
2011 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Requirement for high speed wireless connectivity is propelling research in advanced communication systems. Low power and wide bandwidth of the ultra-wideband technology makes it a potential candidate for high speed data transmission. The six-port based radio systems and wideband antennas have been studied and presented in this dissertation for ultra-wideband applications.

The six-port modulator operation with carrier leakage suppression was demonstrated at a center frequency of 7.5 GHz. The six-port correlator utilizes a quarter wavelength transmission line for carrier leakage suppression, together with diodes or eld effect transistors as variable impedance terminations. Especially, a differential six-port modulator was designed and veried through simulation and measurement. The prototype shows its capability of carrier leakage suppression and high speed data transmission with 256-quadrature amplitude modulation at 50 Msymbol/s at the center frequency of 7.5 GHz. Furthermore, a differential six-port demodulator was demonstrated with the 16 quadrature amplitude modulation at a data rate of 0.8 Gbit/s at the center frequency of 7.5 GHz. It uses zero-bias anti-parallel Schottky diodes as power detectors.

Flexible antennas were designed such that they can be housed by folding it around in space limited environment with stable performance over a wide operation bandwidth. Measurement, on a exible dipole antenna with integrated balun, shows that it covers a frequency band from 6 to 11 GHz at a voltage standing wave ratio lower than 2.5 with the antenna eciency above 86%. A miniaturized monopole antenna that is not only capable of operating over an ultra-wideband but also for lower frequency bands was invented and veried. It covers a frequency range from 1.35 to 11.5 GHz. It gives a quasi-omnidirectional radiation pattern and high eciency. The antenna has a patent pending status with the United States Patent and Trademark Oce.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2011. p. 71
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1403
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-71837 (URN)978-91-7393-052-9 (ISBN)
Public defence
2011-12-01, TP51, Tappan, Campus Norrköping, Norrköping, Norrköping, 10:00 (English)
Opponent
Supervisors
Available from: 2011-11-07 Created: 2011-11-07 Last updated: 2011-11-07Bibliographically approved
Karlsson, M., Owais, O., Östh, J., Serban, A., Gong, S., Jobs, M. & Gruden, M. (2011). Dipole Antenna With Integrated Balun For Ultra-wideband Radio 6-9 GHz. Microwave and optical technology letters (Print), 53(1), 180-184
Open this publication in new window or tab >>Dipole Antenna With Integrated Balun For Ultra-wideband Radio 6-9 GHz
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2011 (English)In: Microwave and optical technology letters (Print), ISSN 0895-2477, E-ISSN 1098-2760, Vol. 53, no 1, p. 180-184Article in journal (Refereed) Published
Abstract [en]

A fully integrated dipole antenna with a balun fot ulna wideband (UWB) radio in the band 6-9 GHz utilizing a flexible and rigid printed count board is presented in this at tide The balun utilizes broadside coupled microstrips and is integrated in the rigid part of the printed coma boat d whereas the radiator is placed in the flexible pat! The antenna with the balun covets the frequency band 6 0-8 5 GHz at voltage standing mate ratio (VSWR) andlt;2 0 and 55-110 GHz at VSWR andlt; 2 5 Moreover simulated and measured radiation patterns and antenna efficiency above 860% are observed

Place, publisher, year, edition, pages
John Wiley & Sons, 2011
Keywords
balun, broadside, coupled, dipole antenna, ultra wideband
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-64238 (URN)10.1002/mop.25656 (DOI)000285231200050 ()
Available from: 2011-01-17 Created: 2011-01-17 Last updated: 2019-08-12Bibliographically approved
Östh, J., Owais, O., Karlsson, M., Serban, A., Gong, S. & Karlsson, P. (2011). Direct Carrier Six-Port Modulator Using a Technique to Suppress Carrier Leakage. IEEE transactions on microwave theory and techniques, 59(3), 741-747
Open this publication in new window or tab >>Direct Carrier Six-Port Modulator Using a Technique to Suppress Carrier Leakage
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2011 (English)In: IEEE transactions on microwave theory and techniques, ISSN 0018-9480, E-ISSN 1557-9670, Vol. 59, no 3, p. 741-747Article in journal (Refereed) Published
Abstract [en]

This paper presents a direct carrier six-port modulator. To allow arbitrary load impedances to be used and for suppression of carrier leakage, a new circuit architecture with a technique to suppress carrier leakage is proposed and implemented. A theoretical model of the proposed modulator is derived. A prototype modulator utilizing diodes for impedance generation is designed and fabricated for a center frequency of 7.5 GHz for verification of the proposed technique. Measurements show good modulation properties when a 16 quadrature amplitude modulation signal at 100 Msymbol/s is generated, as well as good carrier leakage suppression.

Place, publisher, year, edition, pages
IEEE Institute of Electrical and Electronics, 2011
Keywords
Carrier leakage suppression, direct carrier modulator, six-port correlator
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-67308 (URN)10.1109/TMTT.2011.2104972 (DOI)000288460500026 ()
Available from: 2011-04-08 Created: 2011-04-08 Last updated: 2019-06-17Bibliographically approved
Östh, J., Owais, O., Karlsson, M., Serban, A. & Gong, S. (2011). Performance Evaluation of Six-Port Receivers with Simplified Interface to Amplifier and Filter. Paper presented at IEEE International Conference on Ultra-Wideband (ICUWB), 14-16 September 2011, Bologna, Spain.
Open this publication in new window or tab >>Performance Evaluation of Six-Port Receivers with Simplified Interface to Amplifier and Filter
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2011 (English)Conference paper, Oral presentation only (Refereed)
Abstract [en]

In six-port modulators a phase shifting network on specific ports can be used to suppress the carrier leakage that may be present if this network is not present. A model is derived to predict the carrier leakage suppression and error vector magnitude (EVM) as a function of the phase shifting network Sparameters. Both carrier leakage suppression and EVM can be expressed by the same error function. The error function can be used to find the allowed amplitude and phase mismatch in the phase shifting network, or to optimize the performance of a phase shifting network over a given frequency range. A broadband phase shifting network, based on a loaded transmission line, is designed and optimized to operate at a relative bandwidth of 60% for an EVM < 10%. This should be compared to a phase shifting network based on a single transmission line with a corresponding bandwidth of only 12%. The broadband phase shifting network is useful for six-port modulators with carrier leakage suppression, targeting UWB applications.

Keywords
Six-Port Modulator, Carrier Leakage, EVM, Broadband
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-77200 (URN)10.1109/ICUWB.2011.6058824 (DOI)978-1-4577-1762-8 (ISBN)978-1-4577-1763-5 (ISBN)
Conference
IEEE International Conference on Ultra-Wideband (ICUWB), 14-16 September 2011, Bologna, Spain
Available from: 2012-05-08 Created: 2012-05-08 Last updated: 2019-06-17Bibliographically approved
Östh, J., Owais, O., Karlsson, M., Serban, A. & Gong, S. (2011). Schottky diode as high-speed variable impedance load in six-port modulators. In: ICUWB 2011: 2011 IEEE International Conference on Ultra-Wideband (ICUWB). Paper presented at IEEE International Conference on Ultra-Wideband (ICUWB),14-16 September, 2011, Bologna, Spain (pp. 68-71).
Open this publication in new window or tab >>Schottky diode as high-speed variable impedance load in six-port modulators
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2011 (English)In: ICUWB 2011: 2011 IEEE International Conference on Ultra-Wideband (ICUWB), 2011, p. 68-71Conference paper, Oral presentation only (Refereed)
Abstract [en]

The use of Schottky diodes as high-speed variable impedance loads in six-port modulators are proposed and analyzed in this paper. The impedance dependency of diode parameters and local oscillator power are investigated by theoretical analysis and simulations. A prototype for a direct carrier six-port modulator using Schottky diodes for impedance generation is designed and fabricated for a center frequency of 7.5 GHz. Measurements show good modulation properties when a 16 quadrature amplitude modulation signal at 300 Msymbol/s is generated, i.e., at a data rate of 1.2 Gbit/s, validating the use of Schottky diodes as high-speed variable impedance loads in six-port modulators.

Series
IEEE International Conference on Ultra- Wideband (ICUWB), ISSN 2162-6588 ; 2011
Keywords
Schottky diodes, electric impedance measurement, modulators, oscillators, quadrature amplitude modulation
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-77196 (URN)10.1109/ICUWB.2011.6058924 (DOI)978-1-4577-1762-8 (ISBN)978-1-4577-1763-5 (ISBN)
Conference
IEEE International Conference on Ultra-Wideband (ICUWB),14-16 September, 2011, Bologna, Spain
Available from: 2012-05-08 Created: 2012-05-08 Last updated: 2019-06-17Bibliographically approved
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