Khan, Hashim Raza <br/><br/>
Flexible and Adaptive Wideband Switching Power Amplifiers for Transmitters (PhD Thesis) 

 - Karachi :   NED University of Engineering and Technology Department of Electrical Engineering,   2014 
 - XI, 168 p.  : ill 
<br/><br/>Includes Bibliographical References 
<br/><br/> Abstract :<br/><br/>The research work presented in this thesis is focused on the design of flexible and reconfigurable switching power amplifiers for wireless communications. A novel topology of differential Class-E amplifier that uses capacitance with the LC balun to realize inductive impedance is presented. At the same time, the balun provides impedance transformation and incorporates the DC feed network as well to reduce the number of components. <br/><br/>Inverse Class-D is another class of switching amplifier investigated and designed during this research. Analysis showing the efficiency advantage of Class-D­Żą PA over Class-E PA and the maximum transistor size calculation for incorporating the drain capacitance in the output network are presented. <br/><br/>The novel topology of Class-E PA is exploited in RF Pulse Width Modulation based. power amplifier to achieve high efficiency over a wide dynamic range of input signal. Since the Class-E amplifier topology developed in this work requires only capacitors as design elements instead of inductor, it can be realized with tuneable capacitors that are high Q and area efficient components. RFPWM signal is generated by modulating the gate bias of the input inverter stage. Detailed analysis for gate bias vs. duty cycle shows that this technique can be used with polar modulation. <br/><br/>To validate the concepts, several prototypes have been implemented from IBM in 130 nm CMOS technology and measured. The differential Class-E PA with series capacitance with the load delivers an output power of 22 dBm at 2.4 GHz from a 2.5 V supply achieving a PAE of 38%. The fully integrated Class-D­ŻąPA delivers 26.8 dBm power at 1.8 GHz from 2.5 V supply achieving 45% PAE. The RF-PWM design delivers 24.8 dBm power at 1.8 GHz from 2 V DC supply achieving 38% PAE. The PAE decreases to 37% when Pa is reduced to 18.2 dBm. <br/><br/>Thus, Class-EPA with the capacitor based matching network for RF-PWM provides an easy mechanism to achieve a wide range of power over a broad frequency bandwidth with high average efficiency.  
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<br/><br/><label>Subjects--Topical Terms: </label><br/>Impedance Matching Thesis<br/>Amplifiers Radio Frequency Thesis<br/>Power Amplifiers Thesis
<br/><br/><label>Dewey Class. No.: </label>621.38412378242549183  / KHA