A Dual-Band Transistor-Based Rectifier Using Phase Shift and Continuous Mode Parameters With Opposite Polarity

This letter presents a novel design method of dual-frequency transistor-based rectifier. A theoretical analysis establishes for the first time the correlation between continuous class-B/J operational efficiency and critical parameters, including phase shift and continuous mode variable. Analytical findings demonstrate that high efficiency is maintained within an interval phase shift range accompanied by opposite continuous mode parameter. Then, the negative and positive phase offsets are chosen at lower frequency <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${f} _{1}$</tex-math> </inline-formula> and higher frequency <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${f} _{2}$</tex-math> </inline-formula>, respectively. This alleviates the negative effects of traditional fixed phase shift on frequency ratio freedom and efficiency degradation. Furthermore, the phase offset and continuous mode parameters result in an extend load impedance space, providing clear guidance and greater freedom in dual-frequency design. For validation, a dual-band high-efficiency rectifier using a GaN HEMT is designed. Experiments indicate that the peak efficiency of 81.1% and 77.2% is realized at 1.3, 2.1 GHz, respectively, when dc load <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R} _{\text {dc}} = 65~\Omega $</tex-math> </inline-formula>, gate voltage <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V} _{\text {gs}} = -3.0$</tex-math> </inline-formula> V, and input power <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${P} _{\text {in}} =40$</tex-math> </inline-formula> dBm.