| 1. |
- ÖZEN, MUSTAFA, 1984, et al.
(författare)
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Linearization Study of a Highly Efficient CMOS-GaN RF Pulse Width Modulation Based Transmitter
- 2012
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Ingår i: European Microwave Conference. - : IEEE. ; , s. 136-139
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Konferensbidrag (refereegranskat)abstract
- This paper studies linearity of a 2 GHz, 10 Watt peak output power RF pulse width modulation (RF-PWM) based transmitter. The transmitter incorporates a tunable load network class-E PA as the final output stage. The tunable load network enables dynamic optimization of the class-E along with the duty cycle resulting in high efficiency over a wide range of output power levels. A digital predistiortion based linearization scheme is proposed to enhance the linearity of the transmitter. After linearization, the transmitter exhibits an adjacent channel power ratio (ACPR) of -45 dBc with a 3.84 MHz, 6.7 dB peak-to-average power ratio (PAPR) W-CDMA signal. The average drain efficiency of the GaN HEMT output stage is 67% and the total transmitter efficiency is 54%.
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| 2. |
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| 3. |
- ÖZEN, MUSTAFA, 1984, et al.
(författare)
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A Generalized Combiner Synthesis Technique for Class-E Outphasing Transmitters
- 2017
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Ingår i: IEEE Transactions on Circuits and Systems I: Regular Papers. - : Institute of Electrical and Electronics Engineers (IEEE). - 1549-8328 .- 1558-0806. ; 64:5, s. 1126-1139
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a generic combiner design technique is developed for class-E outphasing transmitters. The design procedure starts with calculation of the combiner network parameters that guarantee high efficiency switch mode operation of the PAs in each branch. Recently developed continuous class-E modes theory is then utilized to create an additional degree of freedom for calculation of the combiner network parameters. This additional degree of freedom along with duty cycle control provides an important possibility for achieving high average efficiency over a large bandwidth. A CMOS-GaN outphasing transmitter prototype is realized for experimental verification. The prototype provides drain efficiencies higher than 60% at 6 dB back-off across 750-1050 MHz band. Further, the peak output power remains nearly flat versus frequency, where the variation across the band is +/- 0.18 dB around 44 dBm.
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| 4. |
- ÖZEN, MUSTAFA, 1984, et al.
(författare)
-
High efficiency RF pulse width modulation with tunable load network class-E PA
- 2011
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Ingår i: 2011 IEEE 12th Annual Wireless and Microwave Technology Conference, WAMICON 2011. - 9781612840819
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Konferensbidrag (refereegranskat)abstract
- In this paper, a 10 W peak power 2 GHz highly efficient RF pulse width modulation (RF-PWM) based transmitter is presented. RF-PWM signals are generated with a dedicated 65 nm CMOS modulator and subsequently amplified with a GaN Class-E power amplifier (PA). The modulator use extended drain MOS (EDMOS) high voltage transistors to provide the required voltage swing to drive the GaN used as a switch. The imaginary load impedance of the Class-E is electronically tunable and is implemented with in-house high breakdown voltage SiC varactors. The tunable imaginary load impedance enables optimization of the Class-E versus the duty cycle (pulse width). The peak efficiency is therefore preserved over a wide range of output power levels. The measured drain efficiency of the Class-E output stage is above 70% over a 6.5 dB output power dynamic range. The overall transmitter efficiency is above 60% for the same dynamic range.
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| 5. |
- ÖZEN, MUSTAFA, 1984, et al.
(författare)
-
High-Efficiency RF Pulsewidth Modulation of Class-E Power Amplifiers
- 2011
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 59:11, s. 2931-2942
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- A new switch-mode power-amplifier (SMPA) topology particularly suitable for energy efficient amplification of RF pulsewidth modulation (RF-PWM) signals is derived. It is analytically shown that high efficiency can be maintained over a wide power dynamic range if the imaginary part of the Class-E load impedance is varied along with the duty cycle (pulsewidth). Using the theory developed, an explicit design procedure is presented that allows practical realization of the proposed topology from the circuit and component specifications. Following the design procedure, and using in-house (Chalmers University, Goteborg, Sweden) SiC varactor diodes to implement the tunable imaginary load impedance, a 2-GHz 10-W peak output power GaN HEMT circuit demonstrator is realized. RF-PWM input signals for characterization of the prototype power amplifier (PA) is generated with a dedicated 65-nm CMOS modulator. The measurements show that a drain efficiency > 70% can be obtained over an 6.5-dB dynamic range, which verifies the theory presented and demonstrates the feasibility of the proposed PA topology.
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| 6. |
- ÖZEN, MUSTAFA, 1984, et al.
(författare)
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Wideband and efficient watt-level SiGe BiCMOS switching mode power amplifier using continuous class-E modes theory
- 2014
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Ingår i: Digest of Papers - IEEE Radio Frequency Integrated Circuits Symposium. - 1529-2517. - 9781479938629 ; , s. 243-246
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Konferensbidrag (refereegranskat)abstract
- In this paper, a generic, wide-band switch mode power amplifier (SMPA) design approach is developed based on the continuous class-E modes theory. A watt level, 1.3-2.2 GHz SiGe BiCMOS class-E SMPA is realized for experimental verification. The prototype provides collector efficiencies higher than 70% and output power levels higher than 29 dBm across 1.3-2.2 GHz band, fully confirming the validity of the proposed design approach.
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