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Landin, Per
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Publications (10 of 30) Show all publications
Amin, S., Landin, P. N., Händel, P. & Rönnow, D. (2017). 2D Extended envelope memory polynomial model for concurrent dual-band RF transmitters. International journal of microwave and wireless technologies, 9(8), 1619-1627
Open this publication in new window or tab >>2D Extended envelope memory polynomial model for concurrent dual-band RF transmitters
2017 (English)In: International journal of microwave and wireless technologies, ISSN 1759-0795, E-ISSN 1759-0787, Vol. 9, no 8, p. 1619-1627Article in journal (Refereed) Published
Abstract [en]

The paper presents a 2D extended envelope memory polynomial (2D-EEMP) model for concurrent dual-band radio frequency (RF) power amplifiers (PAs). The model is derived based on the physical knowledge of a dual-band RF PA. The derived model contains cross-modulation terms not included in previously published models; these terms are found to be of importance for both behavioral modeling and digital pre-distortion (DPD). The performance of the derived model is evaluated both as the behavioral model and DPD, and the performance is compared with state-of-the-art2D-DPD and dual-band generalized memory polynomial (DB-GMP) models. Experimental result shows that the proposed model resulted in normalized mean square error (NMSE) of -51.7/-51.6dB and adjacent channel error power ratio (ACEPR) of -63.1/-63.4 dB, for channel 1/2, whereas the 2D-DPD resulted in the largest model error and DB-GMP resulted in model parameters that are 3 times more than those resulted with the proposed model with the same performance. As pre-distorter, the proposed model resulted in adjacent channel power ratio (ACPR) of -55.8/ -54.6 dB for channel 1/2 and is 7-10 dB lower than those resulted with the 2D-DPD model and2-4 dB lower compared to the DB-GMP model.

Keywords
Behavioral modeling and digital predistortion of multi-band amplifiers, Power Amplifiers, RF Front-ends
National Category
Signal Processing
Identifiers
urn:nbn:se:hig:diva-23455 (URN)10.1017/S1759078717000277 (DOI)000418998100010 ()2-s2.0-85018373558 (Scopus ID)
Available from: 2016-12-05 Created: 2017-02-02 Last updated: 2018-03-13Bibliographically approved
Landin, P. & Rönnow, D. (2015). RF PA Modeling Considering Odd-Even and Odd Order Polynomials. In: 2015 IEEE Symposium on Communications and Vehicular Technology in the Benelux (SCVT): . Paper presented at 22nd IEEE Symposium on Communications and Vehicular Technology in the Benelux (IEEE SCVT 2015), Luxembourg, 24 November 2015. New York: Institute of Electrical and Electronics Engineers (IEEE), Article ID 7374233.
Open this publication in new window or tab >>RF PA Modeling Considering Odd-Even and Odd Order Polynomials
2015 (English)In: 2015 IEEE Symposium on Communications and Vehicular Technology in the Benelux (SCVT), New York: Institute of Electrical and Electronics Engineers (IEEE), 2015, article id 7374233Conference paper, Published paper (Refereed)
Abstract [en]

The use of “even” order polynomial terms in radio frequency power amplifier behavioral modeling and digital pre-distortion linearization has long been discussed. This contribution mathematically shows that the purely odd polynomials and the odd-even polynomials are equivalent up to the truncation error inherent in the model itself. The choice of odd or odd-even polynomial is equivalent to a choice of basis functions wherein the odd-even representation does not provide a richer set of basis functions, as earlier has been claimed. Modeling using measured data from a power amplifier shows that the difference in performance between the odd and odd-even polynomials is negligible for models at high nonlinear order. These findings are important to explain the appearance and use of the odd and odd-even models in power amplifier modeling and digital pre-distortion.

Place, publisher, year, edition, pages
New York: Institute of Electrical and Electronics Engineers (IEEE), 2015
Series
IEEE Symposium on Communications and Vehicular Technology in the Benelux, ISSN 2373-0854
Keywords
radio frequency, power amplifier, digital predistortion, polynomial
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:hig:diva-20689 (URN)10.1109/SCVT.2015.7374233 (DOI)000380458800016 ()2-s2.0-84964809927 (Scopus ID)978-1-4673-9907-4 (ISBN)
Conference
22nd IEEE Symposium on Communications and Vehicular Technology in the Benelux (IEEE SCVT 2015), Luxembourg, 24 November 2015
Available from: 2015-11-27 Created: 2015-11-27 Last updated: 2019-01-08Bibliographically approved
Landin, P. N., Barbé, K., Van Moer, W., Isaksson, M. & Händel, P. (2015). Two novel memory polynomial models for modeling of RF power amplifiers. International journal of microwave and wireless technologies, 7(1), 19-29
Open this publication in new window or tab >>Two novel memory polynomial models for modeling of RF power amplifiers
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2015 (English)In: International journal of microwave and wireless technologies, ISSN 1759-0795, E-ISSN 1759-0787, Vol. 7, no 1, p. 19-29Article in journal (Refereed) Published
Abstract [en]

Two novel memory polynomial models are derived based on physical knowledge of a general power amplifier (PA). The derivations are given in detail to facilitate derivations of other model structures. The model error in terms of normalized mean square error (NMSE) and adjacent channel error power ratio (ACEPR) of the novel model structures are compared to that of established models based on the number of parameters using data measured on two different amplifiers, one high-power base-station PA and one low-power general purpose amplifier. The novel models show both lower NMSE and ACEPR for any chosen number of parameters compared to the established models. The low model errors make the novel models suitable candidates for both modeling and digital predistortion.

Keywords
Power amplifiers and linearizers; Wireless systems and signal processing (SDR, MIMO, UWB, etc.)
National Category
Signal Processing
Identifiers
urn:nbn:se:hig:diva-16481 (URN)10.1017/S1759078714000397 (DOI)000348647500003 ()2-s2.0-84921539094 (Scopus ID)
Available from: 2014-04-03 Created: 2014-04-03 Last updated: 2018-11-26Bibliographically approved
Landin, P., Eriksson, T., Fritzin, J. & Alvandpour, A. (2013). Behavioral modeling of outphasing amplifiers considering memory effects. In: 2013 IEEE MTT-S International Microwave Symposium Digest: . Paper presented at 2013 IEEE MTT-S International Microwave Symposium Digest, MTT 2013, 2-7 June 2013, Seattle, WA. IEEE conference proceedings, Article ID 6697764.
Open this publication in new window or tab >>Behavioral modeling of outphasing amplifiers considering memory effects
2013 (English)In: 2013 IEEE MTT-S International Microwave Symposium Digest, IEEE conference proceedings, 2013, article id 6697764Conference paper, Published paper (Refereed)
Abstract [en]

This paper proposes a behavioral model structure for outphasing amplifiers. The model performance is evaluated on a class-D CMOS outphasing amplifier and compared with two models found in the literature. The proposed model structure also allows the use of memory in a parallel Hammerstein-like setting. The proposed models show improvements in adjacent channel error power ratio (ACEPR) of approximately 5 dB in addition to being linear in the parameters. The lower model errors enable the use and design of improved predistorters taking frequency dependency (memory effects) in outphasing amplifiers into account. 

Place, publisher, year, edition, pages
IEEE conference proceedings, 2013
Series
IEEE MTT-S International Microwave Symposium Digest, ISSN 0149-645X
Keywords
CMOS, Nonlinear distortion, Power amplifier, Predistortion, Adjacent channels, Behavioral model, Frequency dependencies, Memory effects, Model errors, Model performance, Pre-distortion, Predistorters, CMOS integrated circuits, Power amplifiers
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:hig:diva-17937 (URN)10.1109/MWSYM.2013.6697764 (DOI)000369754300433 ()2-s2.0-84893322647 (Scopus ID)978-146736176-7 (ISBN)
Conference
2013 IEEE MTT-S International Microwave Symposium Digest, MTT 2013, 2-7 June 2013, Seattle, WA
Available from: 2014-11-11 Created: 2014-11-11 Last updated: 2018-03-13Bibliographically approved
Fritzin, J., Alvandpour, A., Landin, P. & Fager, C. (2013). Linearity, intermodulation distortion and ACLR in outphasing amplifiers. In: 2013 IEEE MTT-S International Microwave Symposium Digest: . Paper presented at 2013 IEEE MTT-S International Microwave Symposium Digest, MTT 2013, 2-7 June 2013, Seattle, WA. IEEE conference proceedings, Article ID 6697584.
Open this publication in new window or tab >>Linearity, intermodulation distortion and ACLR in outphasing amplifiers
2013 (English)In: 2013 IEEE MTT-S International Microwave Symposium Digest, IEEE conference proceedings, 2013, article id 6697584Conference paper, Published paper (Refereed)
Abstract [en]

The distortion from amplitude and phase imbalance in outphasing amplifiers is discussed. The relation between dynamic range (DR) and suppression of distortion is shown to approximately follow a simple linear relationship depending on the DR. Approximate relations between adjacent channel leakage power ratio (ACLR) for different kinds of commonly used communication signals and two-tone intermodulation distortion are given. Relations between loss in output power and reduction of DR as functions of duty cycle in switching-based outphasing amplifiers are also given. An approximate method to evaluate the possible performance of digital pre-distortion (DPD) is also given by considering a DPD capable of correcting all distortions except amplitude imbalance. The predicted performance is compared to the performance obtained using a DPD-model found in the literature. The results show that the method is in good agreement, demonstrating that the proposed method can be used for design and evaluation of predistorted outphasing amplifiers. 

Place, publisher, year, edition, pages
IEEE conference proceedings, 2013
Series
IEEE MTT-S International Microwave Symposium Digest, ISSN 0149-645X
Keywords
CMOS, Nonlinear distortion, Power amplifier, Predistortion, Adjacent channel leakage power ratios, Approximate methods, Communication signals, Design and evaluations, Digital predistortion, Pre-distortion, Predicted performance, Simple linear relationship, CMOS integrated circuits, Power amplifiers, Switching functions, Intermodulation distortion
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:hig:diva-17936 (URN)10.1109/MWSYM.2013.6697584 (DOI)000369754300254 ()2-s2.0-84893262922 (Scopus ID)978-146736176-7 (ISBN)
Conference
2013 IEEE MTT-S International Microwave Symposium Digest, MTT 2013, 2-7 June 2013, Seattle, WA
Available from: 2014-11-11 Created: 2014-11-11 Last updated: 2018-03-13Bibliographically approved
Landin, P. N. & Rönnow, D. (2013). Odd and Odd-Even Memory Polynomial Representations. Gävle: University of Gävle
Open this publication in new window or tab >>Odd and Odd-Even Memory Polynomial Representations
2013 (English)Report (Other academic)
Abstract [en]

It is shown that the absolute value of a complex-valued function can be expressed as a polynomial in the square of the absolute value of the function. A series expansion is given and related to the Volterra-series. The results find application in explaining and improving the understanding of the “even” order memory polynomial models.

Place, publisher, year, edition, pages
Gävle: University of Gävle, 2013. p. 3
Series
Working paper, ISSN 1403-8757 ; 46
Keywords
Volterra, Polynomial model, Complex-valued function
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:hig:diva-24824 (URN)
Available from: 2017-08-11 Created: 2017-08-11 Last updated: 2018-03-13Bibliographically approved
Perea-Tamayo, R., Bengtsson, O., Landin, P. & Heinrich, W. (2012). A modular hybrid switching amplifier for wide-bandwidth supply-modulated RF power amplifiers. In: 7th German Microwave Conference, GeMiC 2012: . Paper presented at 7th German Microwave Conference, GeMiC 2012, 12-14 March 2012, Ilmenau (pp. 6185190).
Open this publication in new window or tab >>A modular hybrid switching amplifier for wide-bandwidth supply-modulated RF power amplifiers
2012 (English)In: 7th German Microwave Conference, GeMiC 2012, 2012, p. 6185190-Conference paper, Published paper (Refereed)
Abstract [en]

A modular hybrid switching amplifier (HSA) for wide-bandwidth supply modulation of RF power amplifiers is presented. The HSA is designed for maximum 15 V supply voltage, 1 A supply current and 10 MHz bandwidth. The purpose is to compare alternative switch technologies. A case study is conducted on GaN-HEMT and Si-MOSFET, which are compared with regards to efficiency and linearity under different load conditions, based on simulations and on measurements of the fabricated designs. Design modifications to accommodate the alternative switch technologies are presented together with analysis of non-linearities including slew-rate induced amplitude distortion.

Keywords
EER, Envelope tracking, hybrid switching amplifiers, power amplifiers, supply modulation, Amplitude distortions, Design modifications, GaN HEMTs, Hybrid-switching, Load condition, RF power amplifiers, Slew-rate, Supply currents, Supply voltages, Gallium nitride, Bandwidth
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:hig:diva-17955 (URN)2-s2.0-84860744344 (Scopus ID)978-398126684-9 (ISBN)
Conference
7th German Microwave Conference, GeMiC 2012, 12-14 March 2012, Ilmenau
Available from: 2014-11-11 Created: 2014-11-11 Last updated: 2018-03-13Bibliographically approved
Landin, P. (2012). Digital Baseband Modeling and Correction of Radio Frequency Power Amplifiers. (Doctoral dissertation). Stockholm: KTH Royal Institute of Technology
Open this publication in new window or tab >>Digital Baseband Modeling and Correction of Radio Frequency Power Amplifiers
2012 (English)Doctoral thesis, monograph (Other academic)
Abstract [en]

Aspects related to behavioral modeling and correction of distortions for radio frequency (RF) power amplifiers (PAs) are treated in the thesis.   

When evaluating the performance of a behavioral model it is important to, first of all, use an evaluation criterion, and second, make sure that the criterion actually tells something about the behavior one wishes to describe. This is used in the weighted error spectral power ratio (WESPR) criterion by means of a frequency dependent weighting function. When the parameters of the models are estimated a suitable error criterion should likewise be used. The frequency weighting function in the WESPR is used in the extraction of the parameters. It is shown on two types of PAs that the model performance measured as WESPR can be improved while the model complexity is reduced compared to the standard frequency neutral criterion.   

When building a model of a system it is advantageous to take account of the physical structure and incorporate this knowledge into the model. It can improve model performance and possibly reduce the number of parameters. By starting from a physically motivated nonlinear model of a RF PA, the commonly used memory polynomial (MP) models are derived. Additionally, three novel MP model structures are derived. Using data measured on a PA it is found that two of these model structures have lower model errors while using fewer parameters than models previously published in the literature.   

Methods to increase the power efficiency and the linearity of RF PAs have been investigated. One of these methods is digital predistortion (DPD) which improves the linearity, thus facilitating operation at higher power levels which improves power efficiency. The other method is a signal shaping method that makes the signal more favorable to the PA by reducing the highest peaks to lower values. It is experimentally shown that the combination of DPD and signal shaping results in an increase of power efficiency in the order of 2-4 times. An instability in the feedback loop that updates the parameters of the DPD was also identified and two solutions were proposed. One solution changes the parameters of the DPD in such a way that the instability is avoided and the other changes the signal to avoid high amplitudes.   

The nonlinear effects of class-D outphasing amplifiers are considered. Four model structures are proposed and evaluated on data measured from two amplifiers. In order to reduce the distortions in the output signal from the amplifiers an algorithm using constant envelope amplitude (purely phase-modulated) signals is proposed. The DPD is evaluated and found to reduce the distortions in a state-of-the-art 32 dBm class-D outphasing PA to make it fulfill the linearity requirements for downlink signals used in the universal mobile telecommunications system (UMTS).

Abstract [sv]

Denna avhandling behandlar ett antal aspekter av digital beteendemodellering och korrektion av effektförstärkare för radiofrekvensapplikationer.   

När prestandan hos en beteendemodell skall bedömas är det för det första viktigt att ha ett utvärderingskriterium och för det andra är det viktigt att detta kriterium fokuserar på de relevanta delarna av beteendet man är intresserad av. Detta används i kriteriet weighted error spectral power ratio (WESPR) genom att en viktning införs. Denna viktning används för att fokusera på de aspekter av beteendet som är viktiga att beskriva. På samma sätt är det viktigt att fokusera på att minimera de relevanta delarna av modellfelet. Genom att använda viktningen från WESPR när parametrarna i beteendemodellen skall estimeras visas det på två olika typer av PA att modellprestandan kan förbättras och modellkomplexiteten reduceras när ett relevant felkriterium används.   

När en modell av ett system byggs är det fördelaktigt att använda den kunskap man har om det fysikaliska systemet. Det kan förbättra modellprestandan samtidigt som antalet parametrar kan reduceras. Genom att börja med en fysikaliskt motiverad modell av en effektförstärkare och införa antaganden härleds de populära minnespolynomen. Dessa har tidigare inte haft någon fysikalisk förklaring. Dessutom härleds tre nya minnespolynom. Av dessa visar två av strukturerna lägre modellfel samtidigt som färre parametrar används än i de tidigare publicerade minnespolynomen.   

Metoder för att förbättra energieffektiviteten och linjariteten i effektförstärkare har undersökts. En av dessa metoder är digital predistorsion (DPD) vilken förbättrar linjariteten och möjliggör på så vis högre uteffekter, vilket i sin tur förbättrar energieffektiviteten. Den andra testade metoden går ut på att förändra signalen genom att reducera effekttopparna så att signalen blir lämpligare för förstärkaren. Det visas experimentellt att kombinationen av dessa metoder kan resultera i förbättringar av energieffektiviteten på 2-4 gånger. En instabilitet i återkopplingsslingan för parameteruppdateringen av DPD identifieras och två förslag på lösningar ges. Det första förslaget modifierar parametrarna så att instabiliteten undviks. Det andra förslaget förändrar signalen så att de höga amplituderna undviks och systemet stabiliseras på detta sätt.   

Slutligen studeras de ickelinjära effekterna i klass-D utfasningsförstärkare. Tre modellstrukturer föreslås och utvärderas på uppmätta data från två olika förstärkare. För att reducera störningarna i utsignalen från förstärkarna föreslås en DPD-algoritm som använder signaler med konstant amplitud (rent fasmodulerade signaler). Denna DPD utvärderas och det visas att den kan reducera störningar i utsignalen hos en modern 32 dBm klass-D utfasande förstärkare så att den uppfyller linjaritetskraven för signaler som används i nedlänken (från basstation till mobil enhet) i telekommunikationssystemet universal mobile telecommunications system (UMTS).

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2012. p. xiii, 197
Series
TRITA-EE, ISSN 1653-5146 ; 2012:013
National Category
Telecommunications Signal Processing
Identifiers
urn:nbn:se:hig:diva-18696 (URN)978-91-7501-303-9 (ISBN)
Public defence
2012-06-07, 33:202, Högskolan i Gävle, Kungsbäcksvägen 47, 13:00 (English)
Opponent
Supervisors
Available from: 2015-01-09 Created: 2015-01-09 Last updated: 2018-03-13Bibliographically approved
Landin, P. N., Fritzin, J., Jung, Y., Enqvist, M., Isaksson, M. & Alvandpour, A. (2012). Digital baseband pre-distortion of class-D outphasing amplifiers. In: Proceedings Gigahertz Symposium 2012. Paper presented at GigaHertz 2012 Symposium, March 6-7, Stockholm.
Open this publication in new window or tab >>Digital baseband pre-distortion of class-D outphasing amplifiers
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2012 (English)In: Proceedings Gigahertz Symposium 2012, 2012Conference paper, Published paper (Other academic)
Abstract [en]

This paper presents a novel structure and method for modeling and digitally pre-distorting outphasing amplifiers. The models and pre-distortion are evaluated on a CMOS low-power class-D outphasing amplifier using uplink WCDMA signals. Using the proposed pre-distorter improves the ACLR by no less than 12 dB making the amplifier fulfill the 3GPP requirements on ACLR.

National Category
Signal Processing Telecommunications
Identifiers
urn:nbn:se:hig:diva-11169 (URN)
Conference
GigaHertz 2012 Symposium, March 6-7, Stockholm
Funder
Swedish Research Council
Available from: 2012-01-02 Created: 2012-01-02 Last updated: 2018-03-13Bibliographically approved
Perea-Tamoya, R., Krellmann, M., Bengtsson, O., Landin, P. N. & Heinrich, W. (2012). Investigation of GaN-HEMT Based Switches for Hybrid Switching Amplifier Supply-Modulators. Frequenz, 66(11-12), 339-345
Open this publication in new window or tab >>Investigation of GaN-HEMT Based Switches for Hybrid Switching Amplifier Supply-Modulators
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2012 (English)In: Frequenz, ISSN 0016-1136, E-ISSN 2191-6349, Vol. 66, no 11-12, p. 339-345Article in journal (Refereed) Published
Abstract [en]

An investigation of GaN-HEMT based switching stages in hybrid switching amplifiers (HSA) for wide-bandwidth supply modulation of RF power amplifiers is presented. The HSA is designed for maximum 15 V supply voltage, 1 A supply current and 10 MHz bandwidth. GaN-HEMT switch designs with alternative gate drive circuitry are investigated with regard to power, efficiency and linearity under different load conditions using simulations and measurements of the fabricated circuits. The full HSA showed an efficiency of 49.7% for a WCDMA envelope. A modified switching stage with improved gate-drive circuitry shows 85% efficiency in a 15 V buck-converter test-circuit for a 10 V conversion at 1 MHz over a 15 Ω load.

Keywords
EER; envelope tracking; hybrid switching amplifiers; power amplifiers supply modulation
National Category
Signal Processing Telecommunications
Identifiers
urn:nbn:se:hig:diva-13680 (URN)10.1515/freq-2012-0100 (DOI)000313934700004 ()2-s2.0-84876539513 (Scopus ID)
Available from: 2013-01-22 Created: 2013-01-22 Last updated: 2018-03-13Bibliographically approved
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