This textbook originated in my research Reconfigurable Rectangular to Polar Converter using Linear Convergence for Multiband and Multimode Wireless Communications submitted at the Panjab University, Chandigarh (India). The book covers the transitional area between low frequency and high frequency wireless circuits. Speciﬁcally, it introduces the fundamental physical principles related to the operation of a typical wireless radio communication system. The intended audience for this book are, primarily, senior engineering students preparing for research in wireless communication systems. At the same time, my hope is that graduate engineering students will ﬁnd this book a useful reference for some of the topics that have been only touched upon in the previous stages of their education, or are explained from a different point of view. Finally, the research students may ﬁnd this book a handy source for the quick answers that are routinely omitted from most textbooks. For their knowledge, a detailed study of designing wireless transmitter architectures using MATLAB/Simulink and System Generator software, synthesis with ISE 10.1 software and implementation on Virtex-2 Xilinx FPGA is given.