Investigation of the dynamic load modulation of an inverse class-F power amplifier with an adaptive matching network

Investigation of load modulated inverse Class-F power amplifier with extended conduction angle

“…In Refs. and , a single pole double throw (SPDT) reflective RF switch based on RF‐MEMS technology is utilized to realize the adaptive matching network, which has very low insertion loss less than 0.45 dB @ 10 GHz. However, only discrete DLM type is achieved.…”

“…Most researchers have made great effect to develop various efficiency enhancement techniques for solving the PAs’ issue of transmitting high PAPR signal with poor efficiency, such as Doherty, envelope tracking, Chireix out‐phasing, pulse width modulation, and pulsed load modulation . As an alternative to above techniques, dynamic load modulation (DLM) technique was first introduced into Class‐E PAs by Rabb, and has been developed for the past few years . DLM technique can be realized by using two possible practical implementations, namely load modulated balanced type and varactor or microelectromechanical systems (MEMS) or laterally diffused metal oxide semiconductor (LDMOS) based DLM type .…”

“…In the continuous DLM type, the tunability feature of tunable output matching network (TOMN) is achieved using varactor or LDMOS device . For discrete DLM type, the load impedance of TOMN changes in discrete steps using MEMS devices . In Ref.…”

“…On the contrary, the LM inverse Class‐F PAs are designed without providing theoretical guidance in Refs. and . Hence, it is worth developing the theory on designing LM HT switch‐mode PAs.…”

“…5 As an alternative to above techniques, dynamic load modulation (DLM) technique was first introduced into Class-E PAs by Rabb,6 and has been developed for the past few years. [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] DLM technique can be realized by using two possible practical implementations, namely load modulated balanced type 7,8 and varactor or microelectromechanical systems (MEMS) or laterally diffused metal oxide semiconductor (LDMOS) based DLM type. [9][10][11][12][13][14][15][16][17][18][19][20][21][22] The load modulated balanced type modulates the load impedance by using a pair of RF power transistor in a quadrature balanced configuration, and high power external control signal is used to modulate the desired load impedance.…”