The new paradigm proposed by the QDA technology for Radio Frequency Power Amplifier (RF PA) stage of a Wireless Transmitter consists on the digital decomposition of the original complex signal into a set of simple constant envelope signals and each one is individually amplified by switched amplifiers operating at their maximum energy efficiency point. This opens the door to the use of switched mode amplifiers, characterized by a higher efficiency and near zero consumption in idle state when compared with the current source amplifiers that are employed in current amplification techniques. QDA technology has 3 different variants with the simplest one, first chip prototype, assuring an average efficiency of 40% for multi-carrier multi-carrier signals for bandwidths up to 250 MHz.
The power signal to be transmitted at the output of this parallelized structure is obtained by combining the set of amplified signals in highly efficient smart combiners specially conceived for QDA. Also, the modular approach of the new concept of QDA technology simplifies implementation of the RF PA: a digital signal processing part that permits higher flexibility on addressing a wider range of applications, with different types of signals and bandwidth needs, unlikely other technologies, by a simple firmware reprogramming; and a power amplifier hardware that can be implemented in diverse technologies (CMOS – Complementary Metal Oxide Semiconductor, GaN – Gallium Nitrite, GaS – Gallium Arsenide and Bipolar).