Abstract: A transformer-based Doherty power amplifier includes a main power amplifier path and an auxiliary power amplifier path which are connected in parallel. The main power amplifier path includes a main power amplifier, and the auxiliary power amplifier path includes an auxiliary power amplifier. The transformer-based Doherty power amplifier further includes a first linear network circuit or a second linear network circuit. The first linear network circuit is arranged at an input of the main power amplifier and is used to compensate for variations of an input capacitance of the main power amplifier, so as to improve the linearity of the main power amplifier. The second linear network circuit is arranged at an input of the auxiliary power amplifier and is used to compensate for variations of an input capacitance of the auxiliary power amplifier, so as to improve the linearity of the auxiliary power amplifier.

Abstract: A radio-frequency (RF) switching system for 5G communications and a method of designing it are disclosed. The RF switching system includes a MMMB switching unit and an antenna. The MMMB switching unit includes a 5G-mode multiband switching subunit including a 5G-mode low-frequency (LF)-band switching subunit and a 5G-mode high-frequency (HF)-band switching subunit partitioned from the 5G-mode LF-band switching subunit at a reference frequency. The 5G-mode LF-band switching subunit is connected to the antenna via a low-pass filter, and the 5G-mode HF-band switching subunit is connected to the antenna via a high-pass filter. The RF switching system for 5G communications has improved isolation performance in both the HF and LF bands and improved insertion loss performance in the HF band.

Abstract: a radio frequency (RF) switching circuit, including: a conducting module, configured to conduct an RF signal; a gate control voltage generating module, configured to provide a gate control voltage for the conducting module to control the conducting module operating at ON-state or OFF-state; wherein the gate control voltage generating module further includes: a first resistance adaptive module, providing a first impedance in a first state for a series branch where the conducting module and the gate control voltage generation module locate, and a second impedance in a second state for the series branch where the conducting module and the gate control voltage generation module locate, wherein the first impedance is greater than the second impedance. FOM is improved comprehensively, and Ron, Coff, and a power breakdown performance are optimized, which further improves circuit performance and reduces cost.

Abstract: A transformer-based Doherty power amplifier includes a main power amplifier path and an auxiliary power amplifier path which are connected in parallel. The main power amplifier path includes a main power amplifier, and the auxiliary power amplifier path includes an auxiliary power amplifier. The transformer-based Doherty power amplifier further includes a first linear network circuit or a second linear network circuit. The first linear network circuit is arranged at an input of the main power amplifier and is used to compensate for variations of an input capacitance of the main power amplifier, so as to improve the linearity of the main power amplifier. The second linear network circuit is arranged at an input of the auxiliary power amplifier and is used to compensate for variations of an input capacitance of the auxiliary power amplifier, so as to improve the linearity of the auxiliary power amplifier.

Abstract: a radio frequency (RF) switching circuit, including: a conducting module, configured to conduct an RF signal; a gate control voltage generating module, configured to provide a gate control voltage for the conducting module to control the conducting module operating at ON-state or OFF-state; wherein the gate control voltage generating module further includes: a first resistance adaptive module, providing a first impedance in a first state for a series branch where the conducting module and the gate control voltage generation module locate, and a second impedance in a second state for the series branch where the conducting module and the gate control voltage generation module locate, wherein the first impedance is greater than the second impedance. FOM is improved comprehensively, and Ron, Coff, and a power breakdown performance are optimized, which further improves circuit performance and reduces cost.

Abstract: A radio-frequency (RF) switching system for 5G communications and a method of designing it are disclosed. The RF switching system includes a MMMB switching unit and an antenna. The MMMB switching unit includes a 5G-mode multiband switching subunit including a 5G-mode low-frequency (LF)-band switching subunit and a 5G-mode high-frequency (HF)-band switching subunit partitioned from the 5G-mode LF-band switching subunit at a reference frequency. The 5G-mode LF-band switching subunit is connected to the antenna via a low-pass filter, and the 5G-mode HF-band switching subunit is connected to the antenna via a high-pass filter. The RF switching system for 5G communications has improved isolation performance in both the HF and LF bands and improved insertion loss performance in the HF band.

Abstract: The embodiments of the present disclosure provide a low noise amplifier including: an input stage circuit; a bias circuit, adapted for providing bias to the input stage circuit; an output stage circuit; a first amplifier and a second amplifier; a first middle stage circuit, adapted for implementing inter-stage matching, signal coupling and isolation between the input stage circuit and the first amplifier; and a second middle stage circuit, adapted for implementing inter-stage matching between the first amplifier and the second amplifier, wherein the first middle stage circuit is coupled with the second middle stage circuit via the first amplifier, and the second middle stage circuit is coupled with the output stage circuit via the second amplifier. Accordingly, amplifier gain of LNA is improved without increasing power consumption.

Abstract: The embodiments of the present disclosure provide a low noise amplifier including: an input stage circuit; a bias circuit, adapted for providing bias to the input stage circuit; an output stage circuit; a first amplifier and a second amplifier; a first middle stage circuit, adapted for implementing inter-stage matching, signal coupling and isolation between the input stage circuit and the first amplifier; and a second middle stage circuit, adapted for implementing inter-stage matching between the first amplifier and the second amplifier, wherein the first middle stage circuit is coupled with the second middle stage circuit via the first amplifier, and the second middle stage circuit is coupled with the output stage circuit via the second amplifier. Accordingly, amplifier gain of LNA is improved without increasing power consumption.