000			02759nam a2200205Ia 4500
008			141124s2014||||xx |||||||||||||| ||eng||
022			_lphd
041			_aeng
082			_a621.38412378242549183 _bKHA
100			_aKhan, Hashim Raza _eAU
245		0	_aFlexible and Adaptive Wideband Switching Power Amplifiers for Transmitters (PhD Thesis)
260			_aKarachi : _bNED University of Engineering and Technology Department of Electrical Engineering, _c2014
300			_aXI, 168 p. _b: ill
504			_aYN
520			_aAbstract : 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. Inverse Class-D is another class of switching amplifier investigated and designed during this research. Analysis showing the efficiency advantage of Class-D­¯¹ PA over Class-E PA and the maximum transistor size calculation for incorporating the drain capacitance in the output network are presented. 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. 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-D­¯¹PA 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. 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.
650		0	_aImpedance Matching Thesis _9882851
650			_aAmplifiers Radio Frequency Thesis _9673545
650			_aPower Amplifiers Thesis
942			_cPHD _2ddc
999			_c361311 _d361311