Article ID: 20.20230502
A method is proposed for a hybrid power supply modulator (PSM) which consists of a wideband linear amplifier (LA), switching converters (SC), and a hysteresis comparator (HC) for an envelope tracking transmitter. By a compensation method of using a dual feedback network, the stability of the LA circuit is realized. A System in Package (SiP) structure based on separated gallium nitride (GaN) devices and the designed LA is proposed to achieve high performance, high reliability, and miniaturization. Ranging from -40 ∼ 100℃ of operating temperature, the 3dB bandwidth of the proposed PSM can reach over 120MHz which achieves the maximum efficiency of 82% at an average output power of over 4W with 2.5 ∼ 4.5V power supply. Using a long-term evolution (LTE) 10MHz quadrature phase shift keying (QPSK) with Peak to Average Power Ratio (PAPR) of 6.5dB at 225 ∼ 512MHz, the envelope tracking transmitter is measured that the power added efficiency (PAE) is 58.95 ∼ 66.96%, Error Vector Magnitude (EVM) is 1.7 ∼ 2.36%.
