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Östh, Joakim
Publications (10 of 25) Show all publications
Östh, J., Karlsson, M., Serban, A. & Gong, S. (2015). A Comparative Study of Single-Ended vs. Differential Six-Port Modulators for Wireless Communications. IEEE Transactions on Circuits and Systems Part 1: Regular Papers, 62(2), 564-570
Open this publication in new window or tab >>A Comparative Study of Single-Ended vs. Differential Six-Port Modulators for Wireless Communications
2015 (English)In: IEEE Transactions on Circuits and Systems Part 1: Regular Papers, ISSN 1549-8328, E-ISSN 1558-0806, Vol. 62, no 2, p. 564-570Article in journal (Refereed) Published
Abstract [en]

If present, nonlinear effects in a six-port modulator cause distortion and degradation of the quality of the modulated output waveform. How nonlinear effects occur and their impact on system performance were derived in a mathematical model. The model shows that non-ideal performance of the passive six-port correlator is the main contributor to nonlinear distortion. Simulations and measurements on two manufactured six-port modulators were used to validate the theory and to give deeper insight on system performance. It is shown that by using a differentially signaled six-port modulator instead of a single-ended six-port modulator, better performance is achieved over a wide bandwidth. For an error vector magnitude of less than 10%, the relative bandwidth was measured to 12% for the single-ended but 30% for the differentially signaled modulator

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2015
Keywords
Differential; modulation order; non-linearity; single-ended; six-port; six-port correlator; six-port modulator
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-115331 (URN)10.1109/TCSI.2014.2362310 (DOI)000349399800025 ()
Available from: 2015-03-13 Created: 2015-03-13 Last updated: 2019-08-12Bibliographically approved
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., Serban, A. & Gong, S. (2013). M-QAM Six-Port Modulator Using Only Binary Baseband Data, Electrical or Optical. IEEE transactions on microwave theory and techniques, 61(6), 2506-2513
Open this publication in new window or tab >>M-QAM Six-Port Modulator Using Only Binary Baseband Data, Electrical or Optical
2013 (English)In: IEEE transactions on microwave theory and techniques, ISSN 0018-9480, E-ISSN 1557-9670, Vol. 61, no 6, p. 2506-2513Article in journal (Refereed) Published
Abstract [en]

A new circuit architecture for a direct-carrier six-port modulator is proposed. The proposed architecture uses parallel binary-valued baseband signals to control binary-valued impedance loads for generation of rectangular M-QAM modulation. A theoretical model of the proposed modulator is also derived. A prototype modulator for 64 quadrature amplitude modulation is designed and fabricated for a center frequency of 2.5 GHz for verification of the proposed architecture. The measurements verify the theory and show that good performance can be obtained with the proposed architecture. The proposed modulator does not require any digital-to-analog converter and can operate with both electrical and optical control signals.

Place, publisher, year, edition, pages
IEEE, 2013
Keywords
Binary baseband; carrier leakage suppression; direct-carrier modulator; six-port correlator
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-96474 (URN)10.1109/TMTT.2013.2259255 (DOI)000319979300024 ()
Available from: 2013-08-23 Created: 2013-08-20 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
Östh, J., Karlsson, M., Serban, A. & Gong, S. (2012). Carrier Leakage Suppression and EVM Dependence on Phase Shifting Network in Six-Port Modulator. In: : . Paper presented at International Conference on Microwave and Millimeter Wave Technology ICMMT, May 5-8, Shenzhen, China (pp. 1-4). IEEE
Open this publication in new window or tab >>Carrier Leakage Suppression and EVM Dependence on Phase Shifting Network in Six-Port Modulator
2012 (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.

Place, publisher, year, edition, pages
IEEE, 2012
Keywords
Six-Port Modulator, Carrier Leakage, EVM, Broadband
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-77194 (URN)10.1109/ICMMT.2012.6230247 (DOI)978-1-4673-2184-6 (ISBN)
Conference
International Conference on Microwave and Millimeter Wave Technology ICMMT, May 5-8, Shenzhen, China
Available from: 2012-05-08 Created: 2012-05-08 Last updated: 2019-06-17Bibliographically approved
Serban, A., Karlsson, M., Östh, J., Owais, O. & Gong, S. (2012). Differential Circuit Technique for Six-Port Modulator and Demodulator. In: Microwave Symposium Digest (MTT), 2012 IEEE MTT-S International: . Paper presented at International Microwave Symposium, June 17-22, Montréal, Canada, 2012. (pp. 1-3). IEEE
Open this publication in new window or tab >>Differential Circuit Technique for Six-Port Modulator and Demodulator
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2012 (English)In: Microwave Symposium Digest (MTT), 2012 IEEE MTT-S International, IEEE , 2012, p. 1-3Conference paper, Published paper (Refereed)
Abstract [en]

Targeting the differential RF/microwave circuit design methodology for improved broadband wireless data transmission, a novel differential 7.5 GHz six-port modulator and demodulator pair was designed and manufactured. Measurements show a good 256-QAM modulated signal at 50 Msymbol/s and an accurately 16-QAM demodulated signal at 200 Msymbol/s.

Place, publisher, year, edition, pages
IEEE, 2012
Series
IEEE - MTTS International Microwave Symposium. Digest, ISSN 0149-645X ; 2012
Keywords
Six-port modulator, six-port demodulator, differential transmission lines, double-sided parallel-strip lines
National Category
Communication Systems
Identifiers
urn:nbn:se:liu:diva-88342 (URN)10.1109/MWSYM.2012.6259763 (DOI)978-1-4673-1086-4 (ISBN)
Conference
International Microwave Symposium, June 17-22, Montréal, Canada, 2012.
Available from: 2013-02-08 Created: 2013-02-04 Last updated: 2019-06-17Bibliographically approved
Östh, J., Serban, A., Karlsson, M. & Gong, S. (2012). LO Leakage in Six-Port Modulators and Demodulators and its Suppression Techniques. In: : . Paper presented at International Microwave Symposium, June 17-22, Montréal, Canada (pp. 1-3). IEEE
Open this publication in new window or tab >>LO Leakage in Six-Port Modulators and Demodulators and its Suppression Techniques
2012 (English)Conference paper, Oral presentation only (Refereed)
Abstract [en]

In a six-port demodulator utilizing diodes for power detection, impedance mismatch at the interface between the six-port correlator and diodes generates unwanted local oscillator (LO) leakage to the radio frequency (RF) port. A six-port modulator that uses variable reflection coefficients at specific ports to generate a modulated RF may also suffer from LO leakage if there is a static part in the reflection coefficient. It is known that LO leakage to the RF port not only generates unwanted emission of the LO signal, but also degrades the receiver system performance due to a dynamic dc offset and second-order non-linearity at the detected baseband signal. How this LO leakage appears to the RF port in six-port demodulators and modulators are analyzed. Two different approaches to suppress the LO leakage is then discussed: a) diode impedance matching and b) introduction of a λ/4 line on specific ports. The performance when λ/4 lines are used on specific ports is verified by measurement for both a demodulator and a modulator. The measurement shows high suppression of the LO leakage.

Place, publisher, year, edition, pages
IEEE, 2012
Keywords
Six-Port Correlator, Six-Port Receiver, LO Leakage, LO Suppression
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-77207 (URN)10.1109/MWSYM.2012.6258402 (DOI)978-1-4673-1086-4 (ISBN)978-1-4673-1085-7 (ISBN)
Conference
International Microwave Symposium, June 17-22, Montréal, Canada
Available from: 2012-05-08 Created: 2012-05-08 Last updated: 2019-06-17Bibliographically approved
Östh, J. (2012). Study of Six-Port Modulators and Demodulators for High-Speed Data Communications. (Doctoral dissertation). Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Study of Six-Port Modulators and Demodulators for High-Speed Data Communications
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

There is an increasing demand for high-speed wireless data communications to support consumers’ need for, among other things, real time streaming of high definition video and fast file transfers. One radio architecture that has a potential to meet the increasing demand for high-speed data communications is a radio technique based on the six-port architecture. In addition to high-speed, the six-port radio also allows low power consumption and low cost. In this thesis, a comprehensive study of the six-port radio technique for high data rate (> 1 Gbit/s) and low complexity are presented.

Firstly, a technique to suppress the carrier leakage was proposed, analyzed and verified by measurements. The proposed technique uses only a phase shifting network between the six-port correlator and its variable impedance loads, hence it is easy to implement. When the proposed carrier leakage suppression technique is used together with differential control signals, it also has the benefit of both improving the linearity and increasing the output power of the modulator. The same carrier leakage suppression technique can also be used in a six-port demodulator (receiver) to improve its performance.

Secondly, Schottky diodes were proposed to be used as high-speed variable impedance loads. A six-port modulator operating at 7.5 GHz, using the carrier leakage suppression technique together with Schottky diodes as variable impedance loads, was manufactured. Measurements on a 16 quadrature amplitude modulated (QAM) signal with a symbol rate of 300 Msymbol/s, i.e., a data rate of 1.2 Gbit/s, have proved high-speed operation, good modulation properties as well as carrier leakage suppression.

Thirdly, a six-port demodulator was built for high data rate applications and measurements were conducted to characterize its performance. Demodulation of a 16-QAM signal at a data rate of 1.67 Gbit/s results in an acceptable bit error rate and error vector magnitude (EVM) performance.

Last but not least, new diode configurations were proposed, analyzed and verified for use in six-port demodulators. Using the proposed diode configurations, the use of differential amplifiers, as commonly used in a six-port demodulator, can be avoided. Avoiding the use of differential amplifiers allows high-speed processing and at the same time reduces the power consumption and implementation complexity. In the context of the new diode configurations, it was shown that a six-port receiver has better EVM vs frequency performance and lower implementation complexity, compared to a five-port or four-port receiver.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2012. p. 79
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1445
National Category
Communication Systems
Identifiers
urn:nbn:se:liu:diva-76087 (URN)978-91-7519-899-6 (ISBN)
Public defence
2012-05-31, K1, Kåkenhus, Campus Norrköping, Linköpings universitet, Norrköping, 10:00 (English)
Opponent
Supervisors
Available from: 2012-05-08 Created: 2012-03-26 Last updated: 2019-12-10Bibliographically approved
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
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