Efficiency improvement of power amplifiers without degraded linearity using a new topology and control method

2011-11-21
Ronaghzadeh, Amin
Demir, Şimşek
This paper presents a medium-power amplifier designed in class AB at 2.4 GHz with two transistors of the same type in parallel. Keeping the drain bias of the transistors constant, it is demonstrated that by careful selection of the transistor and dynamically tuning the gate bias of the individual devices and output matching of the whole amplifier according to input drive level, an increase of about 40% in PAE is achieved at 7 dB back-off from the P1dB of the class AB amplifier employing a fixed bias and matching network and giving the same maximum output power. On the other hand, at higher drive levels while maintaining the PAE nearly constant (the same situation that is experienced in Doherty techniques), a maximum improvement of 7 dB can be observed at 1 dB compression point. © 2011 IEEE.

Suggestions

Hybrid connection of RF MEMS and SMT components in an impedance tuner
Unlu, Mehmet; Topalli, Kagan; Atasoy, Halil Ibrahim; Demir, Şimşek; Aydın Çivi, Hatice Özlem; Akın, Tayfun (Elsevier BV, 2010-01-01)
This paper presents a systematic construction of a model for a hybrid connected RF MEMS and SMT components in a reconfigurable impedance tuner. The double stub hybrid impedance tuner which employs a high number of MEMS switches is selected to demonstrate the feasibility of the connections. In the hybrid tuner, MEMS switches are actuated with DC bias signals, where SMT resistors de-couple RF from the DC lines. The hybrid tuner is realized in two steps, where the MEMS impedance tuner is fabricated on a glass ...
Reliability improvement of RF MEMS devices based on lifetime measurements
Gürbüz, Ozan Doğan; Demir, Şimşek; Akın, Tayfun; Department of Electrical and Electronics Engineering (2010)
This thesis presents fabrication of shunt, capacitive contact type RF MEMS switches which are designed according to given mm-wave performance specifications. The designed switches are modified for investigation in terms of reliability and lifetime. To observe the real-time performance of switches a time domain measurement setup is established and a CV (capacitance vs. voltage) curve measurement system is also included to measure CV curves, pull-in and hold-down voltages and the shifts of these due to actuat...
DC Link Capacitor Optimization for Integrated Modular Motor Drives
Ugur, Mesut; Keysan, Ozan (2017-06-21)
In this paper, selection of optimum DC link capacitor for Integrated Modular Motor Drives (IMMD) is presented. First, a review of IMMD technologies is given and current research and future prospects are studied. Inverter topologies and gate drive techniques are evaluated in terms of DC link performance. The urge for volume reduction in IMMD poses a challenge for the selection of optimum DC link capacitor. DC Link capacitor types are discussed and critical aspects in selecting the DC links capacitor are list...
CMOS readout electronics for mis-matched and mode-matched MEMS gyroscopes
Yeşil, Ferhat; Akın, Tayfun; Department of Electrical and Electronics Engineering (2015)
This thesis presents the CMOS readout electronics for both mismatched and mode-matched MEMS gyroscopes. A systematic design of MEMS gyroscope's control loop parameters, which is insensitive to sensor parameters and environmental conditions, is necessary for robust and high performance operation. Extra to the systematic design for high performance operation, some special techniques should be used to further increase the performance of the sensor. In this thesis, as a performance increasing technique, mode-ma...
Performance Evaluation and Selection of PWM Switching and Control Methods for Grid Connected Modular Multilevel Converters
Ciftci, Baris; Hava, Ahmet Masum (2015-09-24)
This paper focuses on the determination of suitable carrier based pulse width modulation (PWM) switching and control methods for grid connected modular multilevel converters (MMCs). Characterization of various level-shifted and phase-shifted carrier based PWM methods are provided in terms of output voltage waveforms both for N+1 and 2N+1 level output phase voltages. Carrier based PWM method based control approaches are evaluated for MMC. Performances of different control methods are evaluated and compared f...
Citation Formats
A. Ronaghzadeh and Ş. Demir, “Efficiency improvement of power amplifiers without degraded linearity using a new topology and control method,” presented at the 2011 30th URSI General Assembly and Scientific Symposium, URSIGASS 2011, İstanbul, Türkiye, 2011, Accessed: 00, 2022. [Online]. Available: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=81255209020&origin=inward.