ADAPTIVE CONTROL OF POWER AMPLIFIER LINEARIZATION TECHNIQUES BY USING HYBRID ANALOG AND DIGITAL APPROACHES

2021-9
Abdulwahab, Bassam
Power Amplifiers (PA) are widely used in mobile communication systems, yet power amplifiers have a non-linear region which is the major problem in all communication and radar systems. Moreover, PAs show a low power efficiency when operating in their linear region and are highly non-linear when operating in their high-efficiency region. To overcome such issues, there are different methods to linearize PAs and other methods to enhance their power efficiency. These linearization methods are built to meet a certain linearity level for a specific application. However, the linearization techniques are not built to cope with the changes that might occur to the system. In this thesis an adaptive control mechanism for linearization techniques is studied, the goal is to achieve a linearization system for the PA that can maintain the desired linearity level without compromising the efficiency. The idea of the system is to find an intelligent way that can be added to any linearization technique to detect and measure any changes in the system and the effect of this change on the system, then adapt the system to overcome this change and achieve linearity. A digitally programmable feedback control system will be added to the PA linearization technique, having a microcontroller in a feedback vi circuitry that will work as an efficient detector to detect any changes on the sampled signal with accuracy as to control an adaptive network. Accordingly, the microcontroller will decide the voltage control changes required to maintain the required linearity.

Suggestions

Development of X-Band Transceiver MMIC's Using GaN Technology
Memioglu, Onur; Kazan, Oguz; Turan, Isinsu; Karakuzulu, Alper; Gundel, Adnan; Kocer, Fatih; Aydın Çivi, Hatice Özlem (2019-01-01)
This paper describes X-Band power amplifier (PA), low noise amplifier (LNA) and switches that can be used in transmit/ receive modules which are developed with GaN technology. For Transmit chain two 25 W high power amplifiers that are tuned between 8-10 GHz and 10-12 GHz bands are designed. A low noise amplifier with 2 W survivability and less than 2dB noise figure is designed for receive chain. Furthermore, an RF switch that is capable of withstanding 25 W RF power is developed for the selection of transmi...
Adaptive fuzzy hysteresis band current control for reducing switching losses of hybrid active power filter
Durna, Emre (2018-05-01)
Although hysteresis band current control is an easy to implement and robust control method for industrial power electronics converters, it has also some disadvantages like variable and high switching frequency causing high switching losses. In this study, a novel adaptive fuzzy hysteresis band current control system is proposed by making use of fuzzy expressions of both hybrid active power filter (HAPF) current and integral of its harmonic components to reduce the switching losses of three-phase three-wire ...
Broadband spatial power combining in coaxial medium
Tanç, Zafer; Demir, Şimşek; Department of Electrical and Electronics Engineering (2012)
Microwave amplifiers having high output power are the essential components in many systems, such as radar and satellite communication. Although the structures generated by tube technologies fulfill the necessity of the required output power, the use of these amplifiers includes some critical drawbacks, one of which is the limited life of operation. Alternatively, solid-state amplifiers produced by transistor technology are preferred since they are high reliable devices. In order to provide the necessary out...
Adaptive output feedback control with reduced sensitivity to sensor noise
Kutay, Ali Türker; Hovakimyan, N (2003-01-01)
We address adaptive output feedback control of uncertain nonlinear systems with noisy output measurements, in which both the dynamics and the dimension of the regulated system may be unknown, and only the relative degree of the regulated output is assumed to be known. Given a smooth reference trajectory, the problem is to design a controller that forces the system measurement to track it with bounded errors. A recently developed method proposes the use of a linear error observer that estimates the tracking ...
Linearization of RF power amplifiers with memoryless baseband predistortion method
Kolcuoğlu, Turusan; Demir, Şimşek; Department of Electrical and Electronics Engineering (2011)
In modern wireless communication systems, advanced modulation techniques are used to support more users by handling high data rates and to increase the utilization efficiency of the limited RF spectrum. These techniques are sensitive to the nonlinear distortions due to their high peak to average power ratios. Main source of nonlinear distortion in transmitter topologies are power amplifiers that determine the overall efficiency and linearity of the transmitter. To increase linearity without sacrificing effi...
Citation Formats
B. Abdulwahab, “ADAPTIVE CONTROL OF POWER AMPLIFIER LINEARIZATION TECHNIQUES BY USING HYBRID ANALOG AND DIGITAL APPROACHES,” M.S. - Master of Science, Middle East Technical University, 2021.