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Publications (10 of 14) Show all publications
Cijvat, E. (2010). CMOS Integrated Switched-Mode Transmitters for Wireless Communication. In: Paul K Chu (Ed.), Advances in Solid State Circuits Technologies: . INTECH
Open this publication in new window or tab >>CMOS Integrated Switched-Mode Transmitters for Wireless Communication
2010 (English)In: Advances in Solid State Circuits Technologies / [ed] Paul K Chu, INTECH, 2010Chapter in book (Other academic)
Place, publisher, year, edition, pages
INTECH, 2010
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Physics, Electrotechnology
Identifiers
urn:nbn:se:lnu:diva-29917 (URN)978-953-307-086-5 (ISBN)
Available from: 2013-10-23 Created: 2013-10-22 Last updated: 2013-11-05Bibliographically approved
Bassoo, V., Tom, K., Mustafa, A. K., Cijvat, E., Sjöland, H. & Faulkner, M. (2009). A potential transmitter architecture for future generation green wireless base station. EURASIP Journal on Wireless Communications and Networking, Article ID 821846.
Open this publication in new window or tab >>A potential transmitter architecture for future generation green wireless base station
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2009 (English)In: EURASIP Journal on Wireless Communications and Networking, ISSN 1687-1472, E-ISSN 1687-1499, article id 821846Article in journal (Refereed) Published
Abstract [en]

Current radio frequency power amplifiers in 3G base stations have very high power consumption leading to a hefty cost and negative environmental impact. In this paper, we propose a potential architecture design for future wireless base station. Issues associated with components of the architecture are investigated. The all-digital transmitter architecture uses a combination of envelope elimination and restoration (EER) and pulse width modulation (PWM)/pulse position modulation (PPM) modulation. The performance of this architecture is predicted from the measured output power and efficiency curves of a GaN amplifier. 57% efficiency is obtained for an OFDM signal limited to 8 dB peak to average power ratio. The PWM/PPM drive signal is generated using the improved Cartesian sigma delta techniques. It is shown that an RF oversampling by a factor of four meets the WLAN spectral mask, and WCDMA specification is met by an RF oversampling of sixteen.

National Category
Communication Systems
Identifiers
urn:nbn:se:lnu:diva-61606 (URN)10.1155/2009/821846 (DOI)000273489800001 ()
Available from: 2017-03-21 Created: 2017-03-21 Last updated: 2017-11-29Bibliographically approved
Cijvat, E. & Lundin, R. (2009). Miljöföreläsningar med simulerad klimatkonferens i elektronikundervisning. Lund: Lunds Tekniska Högskola
Open this publication in new window or tab >>Miljöföreläsningar med simulerad klimatkonferens i elektronikundervisning
2009 (Swedish)Other (Other (popular science, discussion, etc.))
Place, publisher, year, pages
Lund: Lunds Tekniska Högskola, 2009. p. 1
National Category
Learning
Identifiers
urn:nbn:se:lnu:diva-61591 (URN)
Available from: 2017-03-21 Created: 2017-03-21 Last updated: 2017-04-11Bibliographically approved
Cijvat, E. & Lundin, R. (2009). Miljöföreläsningar med simulerad klimatkonferens i elektronikundervisning. In: Anders Sonesson, Gunilla Amnér (Ed.), Proceedings Utvecklingskonferens 09, Lunds universitet: . Paper presented at Utvecklingskonferens 09, Lund. (pp. 185-192).
Open this publication in new window or tab >>Miljöföreläsningar med simulerad klimatkonferens i elektronikundervisning
2009 (Swedish)In: Proceedings Utvecklingskonferens 09, Lunds universitet / [ed] Anders Sonesson, Gunilla Amnér, 2009, p. 185-192Conference paper, Published paper (Other academic)
National Category
Electrical Engineering, Electronic Engineering, Information Engineering Learning
Identifiers
urn:nbn:se:lnu:diva-29913 (URN)978-91-977974-2-9 (ISBN)
Conference
Utvecklingskonferens 09, Lund.
Available from: 2013-10-23 Created: 2013-10-22 Last updated: 2013-11-05Bibliographically approved
Bassoo, V., Tom, K., Mustafa, A. K., Cijvat, E., Sjöland, H. & Faulkner, M. (2009). Potential Architecture for Future Generation "Green" Wireless Base Station. In: 2009 4th International Symposium on Wireless and Pervasive Computing, ISWPC 2009: . Paper presented at 2009 4th International Symposium on Wireless and Pervasive Computing, ISWPC 2009; Melbourne, Australia; 11-13 February 2009. IEEE, Article ID 4800602.
Open this publication in new window or tab >>Potential Architecture for Future Generation "Green" Wireless Base Station
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2009 (English)In: 2009 4th International Symposium on Wireless and Pervasive Computing, ISWPC 2009, IEEE, 2009, article id 4800602Conference paper, Published paper (Refereed)
Abstract [en]

Current radio frequency power amplifiers (PAs) in 3G base stations have very high power consumption leading to a hefty cost and negative environmental impact. In this paper, we propose a potential architecture design for future wireless base station. Issues associated with components of the architecture are investigated. A comparison of PA with pulse width modulation drive and PA with envelope elimination and restoration (EER) drive is offered. EER-driven PA promises high efficiency over a wide dynamic range but has bandwidth expansion problems. A novel approach which reduces bandwidth expansion on the envelope by 54% is proposed. A modulator is used to convert amplitude and phase information into the edges of a pulse train. The modulator also eradicates some analog components present in traditional base station design.

Place, publisher, year, edition, pages
IEEE, 2009
National Category
Communication Systems
Identifiers
urn:nbn:se:lnu:diva-61594 (URN)10.1109/ISWPC.2009.4800602 (DOI)000267363700054 ()9781424429660 (ISBN)
Conference
2009 4th International Symposium on Wireless and Pervasive Computing, ISWPC 2009; Melbourne, Australia; 11-13 February 2009
Available from: 2017-03-21 Created: 2017-03-21 Last updated: 2017-03-22Bibliographically approved
Cijvat, E., Sjöland, H., Tom, K. & Faulkner, M. (2008). A comparison of polar transmitter architectures using a GaN HEMT power amplifier. In: 15th IEEE International Conference on Electronics, Circuits and Systems, ICECS 2008.: . Paper presented at The 15th IEEE International Conference on Electronics, Circuits and Systems, ICECS 2008, Malta, Aug. 31 2008-Sept. 3, 2008 (pp. 1075-1078). IEEE Press
Open this publication in new window or tab >>A comparison of polar transmitter architectures using a GaN HEMT power amplifier
2008 (English)In: 15th IEEE International Conference on Electronics, Circuits and Systems, ICECS 2008., IEEE Press, 2008, p. 1075-1078Conference paper, Published paper (Refereed)
Abstract [en]

In this paper three transmitter architectures are compared, that each use the low-frequency envelope and high-frequency phase component of an RF signal. A power amplifier (PA) with Pulse Width Modulation by Variable Gate Bias (PWMVGB) is compared to an Envelope Elimination and Restoration (EER) and Envelope Tracking (ET) configuration. The test circuit is implemented using a discrete GaN HEMT power amplifier and discrete surface-mount passive components assembled on a PCB. Measurements show that the EER architecture maintains a drain efficiency of 56 to 69% for a wide output power range, while the PA with variable gate bias shows a significant drop in efficiency for lower output powers (from 59 to 6%). Other comparison issues are modulation of the supply voltage and transmitter complexity.

Place, publisher, year, edition, pages
IEEE Press, 2008
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Physics, Electrotechnology
Identifiers
urn:nbn:se:lnu:diva-29912 (URN)10.1109/ICECS.2008.4675043 (DOI)978-1-4244-2181-7 (ISBN)
Conference
The 15th IEEE International Conference on Electronics, Circuits and Systems, ICECS 2008, Malta, Aug. 31 2008-Sept. 3, 2008
Available from: 2013-10-23 Created: 2013-10-22 Last updated: 2013-11-05Bibliographically approved
Cijvat, E., Tom, K., Faulkner, M. & Sjöland, H. (2008). Comparing polar transmitter architectures using a GaN HEMT power amplifier. In: Jan Grahn (Ed.), Abstracts book of The Gigahertz Symposium 2008: 5-6 March, 2008, Chalmers University of Technology, Göteborg, Sweden. Paper presented at The Gigahertz Symposium 2008, 5-6 March, 2008, Chalmers University of Technology, Göteborg, Sweden (pp. 21-21). Gothenburg: Chalmers University of Technology
Open this publication in new window or tab >>Comparing polar transmitter architectures using a GaN HEMT power amplifier
2008 (English)In: Abstracts book of The Gigahertz Symposium 2008: 5-6 March, 2008, Chalmers University of Technology, Göteborg, Sweden / [ed] Jan Grahn, Gothenburg: Chalmers University of Technology , 2008, p. 21-21Conference paper, Oral presentation with published abstract (Other academic)
Abstract [en]

A power amplifier (PA) with variable gate bias is compared to an Envelope Elimination and Restoration (EER) configuration. Each use the lowfrequency envelope and high-frequency phase component of the signal. The test circuit is implemented using a discrete GaN HEMT power device. Measurements show that the EER architecture maintains a relatively high drain efficiency for a wide output power range, while the PA with variable gate bias shows a significant drop in efficiency for lower output powers.

Place, publisher, year, edition, pages
Gothenburg: Chalmers University of Technology, 2008
National Category
Signal Processing
Research subject
Physics, Waves and Signals
Identifiers
urn:nbn:se:lnu:diva-61596 (URN)
Conference
The Gigahertz Symposium 2008, 5-6 March, 2008, Chalmers University of Technology, Göteborg, Sweden
Available from: 2017-03-21 Created: 2017-03-21 Last updated: 2018-05-31Bibliographically approved
Cijvat, E. & Sjoland, H. (2008). Two 130nm CMOS class-D RF power amplifiers suitable for polar transmitter architectures. In: 9th International Conference on Solid-State and Integrated-Circuit Technology, ICSICT 2008.: . Paper presented at International conference on solid-state and integrated circuit technology, 20-23 Oct. 2008, Beijing, China, (pp. 1380-1383). IEEE Press
Open this publication in new window or tab >>Two 130nm CMOS class-D RF power amplifiers suitable for polar transmitter architectures
2008 (English)In: 9th International Conference on Solid-State and Integrated-Circuit Technology, ICSICT 2008., IEEE Press, 2008, p. 1380-1383Conference paper, Published paper (Refereed)
Abstract [en]

Two class-D RF power amplifiers consisting of CMOS inverter chains have been designed and measured. The first amplifier operates at 1GHz and has a maximum output power of 12dBm, whereas the second operates at 1.5GHz and outputs a maximum of 6dBm. The amplifiers have been characterized for use in two different polar transmitter architectures, Pulse Width Modulation by Variable Gate Bias (PWMVGB) and Envelope Elimination and Restoration (EER). Using a standard 130nm digital CMOS process and off-chip passive components, maximum drain efficiencies of 32% and 39%, respectively, are achieved. The two amplifiers are compared with respect to output power and drain efficiency, including a qualitative analysis of losses. Moreover, their use in the two polar transmitter architectures is discussed.

Place, publisher, year, edition, pages
IEEE Press, 2008
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:lnu:diva-61595 (URN)10.1109/ICSICT.2008.4734800 (DOI)000265971002021 ()978-1-4244-2185-5 (ISBN)978-1-4244-2186-2 (ISBN)
Conference
International conference on solid-state and integrated circuit technology, 20-23 Oct. 2008, Beijing, China,
Available from: 2017-03-21 Created: 2017-03-21 Last updated: 2017-03-22Bibliographically approved
Cijvat, E., Tom, K., Faulkner, M. & Sjöland, H. (2007). A GaN HEMT Power Amplifier with Variable Gate Bias for Envelope and Phase Signals. In: Proceedings of Norchip 2007, Aalborg, Denmark, 2007: . Paper presented at Norchip 2007, Aalborg, Denmark, 19-20 Nov. 2007. Aalborg, Denmark: Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>A GaN HEMT Power Amplifier with Variable Gate Bias for Envelope and Phase Signals
2007 (English)In: Proceedings of Norchip 2007, Aalborg, Denmark, 2007, Aalborg, Denmark: Institute of Electrical and Electronics Engineers (IEEE), 2007Conference paper, Published paper (Refereed)
Abstract [en]

This paper describes the design, simulation and measurement of a GaN power amplifier suitable for envelope and phase signal combination. The low-frequency envelope signal is used to vary the gate (bias) voltage of the device, resulting in a pulse width modulated drain voltage, while modulation of supply voltage or current is avoided. The test circuit is implemented using a discrete GaN HEMT power amplifier and discrete surface-mount passive components assembled on a PCB. Measurements showed a maximum drain efficiency of 59% at 360 MHz, at an output power of 29 dBm. The output power as a function of the gate bias voltage varied between 3 and 29 dBm, with the drain efficiency varying between 6 and 59%.

Place, publisher, year, edition, pages
Aalborg, Denmark: Institute of Electrical and Electronics Engineers (IEEE), 2007
National Category
Signal Processing
Identifiers
urn:nbn:se:lnu:diva-61599 (URN)10.1109/NORCHP.2007.4481050 (DOI)9781424415175 (ISBN)
Conference
Norchip 2007, Aalborg, Denmark, 19-20 Nov. 2007
Available from: 2017-03-21 Created: 2017-03-21 Last updated: 2017-04-11Bibliographically approved
Cijvat, E., Troedsson, N. & Sjöland, H. (2005). A 2.4GHz CMOS Power Amplifier Using Internal Frequency Doubling. In: IEEE International Symposium on Circuits and Systems, 2005. ISCAS 2005: . Paper presented at IEEE International Symposium on Circuits And Systems (ISCAS) ’05, 23-26 May, 2005 (pp. 2683-2686). Kobe, Japan: IEEE Press
Open this publication in new window or tab >>A 2.4GHz CMOS Power Amplifier Using Internal Frequency Doubling
2005 (English)In: IEEE International Symposium on Circuits and Systems, 2005. ISCAS 2005, Kobe, Japan: IEEE Press, 2005, p. 2683-2686Conference paper, Published paper (Refereed)
Abstract [en]

A fully integrated 0.18 /spl mu/m 1P6M CMOS power amplifier using internal frequency doubling is presented. Two chips were measured, one stand-alone PA and one PA with a VCO on the same chip. Since the PA and VCO operate at different frequencies, this configuration is suitable for direct-upconversion or low-IF upconversion since oscillator pulling is reduced. The maximum output power is 15 dBm, and the maximum drain efficiency is 10.7% at an output operating frequency of 2.4 GHz.

Place, publisher, year, edition, pages
Kobe, Japan: IEEE Press, 2005
National Category
Signal Processing
Identifiers
urn:nbn:se:lnu:diva-61600 (URN)10.1109/ISCAS.2005.1465179 (DOI)
Conference
IEEE International Symposium on Circuits And Systems (ISCAS) ’05, 23-26 May, 2005
Available from: 2017-03-21 Created: 2017-03-21 Last updated: 2017-04-11Bibliographically approved
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-9188-4566

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