Abstract: A grouting device for high-coagulability grouting materialsincludes a grouting pipe, a connector and a self-sealing pipe head, wherein one end of the connector is connected with a grouting pump through the grouting pipe, the other end of the connector is connected with the self-sealing pipe head through the grouting pipe, and the grouting pipe is connected with the connector and the self-sealing pipe head in a fixed and sealed mode. The grouting device is easy to install, features reliable connection between the grouting pipe and the connector and the self-sealing pipe head, and can be reused. Because the inner diameter of the connector is consistent with the inner diameter of the grouting pipe, and a slurry outlet on an end cap of the self-sealing pipe head is a circular slurry outlet, pressure loss in the grouting process is effectively reduced, and the grouting effect is good.

Abstract: The invention relates to the grouting field, in particular to a grouting device for high-coagulability grouting materials. The grouting device comprises a grouting pipe, a connector and a self-sealing pipe head, wherein one end of the connector is connected with a grouting pump through the grouting pipe, the other end of the connector is connected with the self-sealing pipe head through the grouting pipe, and the grouting pipe is connected with the connector and the self-sealing pipe head in a fixed and sealed mode. The grouting device is easy to install, features reliable connection between the grouting pipe and the connector and the self-sealing pipe head, and can be reused. Because the inner diameter of the connector is consistent with the inner diameter of the grouting pipe, and a slurry outlet on an end cap of the self-sealing pipe head is a circular slurry outlet, pressure loss in the grouting process is effectively reduced, and the grouting effect is good.

Abstract: There is disclosed a method for controlling a power amplifier capable of utilizing nonlinearity correction in a nearly steady operation status of non-linearity correction, in a periodical fast switching system in time domain. The method may comprise receiving a periodic switch signal indicating switch time of the periodical fast switching system; and providing, based on the periodic switch signal, a pre-bias signal with a pre-determined voltage amplitude to the power amplifier for a pre-determined time period before each downlink time slot to preheat a transistor of the power amplifier so as to compensate a temperature change of a die inside the transistor.

Abstract: A multi-way Doherty power amplifier, DPA, is disclosed, comprising a first path comprising a carrier amplifier or at least one carrier amplifier segment partitioned from the carrier amplifier; a second to N-th paths each comprising at least one carrier amplifier segment and/or at least one peaking amplifier segment partitioned from a peaking amplifier; and a power splitter for splitting an input power signal to each of the at least one carrier amplifier segment and/or at least one peaking amplifier segment in a same path, wherein N is an integer not less than 2; a signal preparation unit configured for generating separately input power signal for the first path and each of the second path to N-th paths; and an impedance inverting network configured for combining output signal power from each path. The performance of each amplifier cell can be maximized independently without any compromises made for each other.

Abstract: There is disclosed a method for controlling a power amplifier capable of utilizing nonlinearity correction in a nearly steady operation status of non-linearity correction, in a periodical fast switching system in time domain. The method may comprise receiving a periodic switch signal indicating switch time of the periodical fast switching system; and providing, based on the periodic switch signal, a pre-bias signal with a pre-determined voltage amplitude to the power amplifier for a pre-determined time period before each downlink time slot to preheat a transistor of the power amplifier so as to compensate a temperature change of a die inside the transistor.

Abstract: The present disclosure provides a multi-way Doherty amplifier that includes an amplifier input, an amplifier output, a main amplifier having an input connected to the amplifier input, and at least a first and a second peak amplifier. In the Doherty amplifier, an input of the first peak amplifier is connected to the amplifier input or an output of the main amplifier, and an input of the second peak amplifier is connected to the amplifier input, the output of the main amplifier or an output of the first peak amplifier. The Doherty amplifier further comprises a first impedance converter connected between the output of the main amplifier and the amplifier output, a second impedance converter connected between the output of the first peak amplifier and an output of the second peak amplifier, and a third impedance converter connected between the output of the second peak amplifier and the amplifier output.

Abstract: A multi-way Doherty power amplifier, DPA, is disclosed, comprising a first path comprising a carrier amplifier or at least one carrier amplifier segment partitioned from the carrier amplifier; a second to N-th paths each comprising at least one carrier amplifier segment and/or at least one peaking amplifier segment partitioned from a peaking amplifier; and a power splitter for splitting an input power signal to each of the at least one carrier amplifier segment and/or at least one peaking amplifier segment in a same path, wherein N is an integer not less than 2; a signal preparation unit configured for generating separately input power signal for the first path and each of the second path to N-th paths; and an impedance inverting network configured for combining output signal power from each path. The performance of each amplifier cell can be maximized independently without any compromises made for each other.

Abstract: A power amplifier (20) for operation in at least a first and a second frequency band, wherein a center frequency f2 of the second frequency band is higher than a center frequency f1 of the first frequency band, is disclosed. The power amplifier (20) comprises a transistor (35) for amplifying an input signal of the power amplifier (20) and an output coupling network (45) for connecting the power amplifier to a resistive load (55). The output coupling network (45) is operatively connected to an output terminal (40) of the transistor (35), has an output terminal (50) for connection to said resistive load (55), and is configured such that, when the power amplifier (20) is connected to said resistive load (55), the power amplifier (20) is arranged to operate in class F for frequencies in one of the first and the second frequency bands, and operate in inverse class F for frequencies in the other one of the first and the second frequency band.

Abstract: The present disclosure provides a multi-way Doherty amplifier that includes an amplifier input, an amplifier output, a main amplifier having an input connected to the amplifier input, and at least a first and a second peak amplifier. In the Doherty amplifier, an input of the first peak amplifier is connected to the amplifier input or an output of the main amplifier, and an input of the second peak amplifier is connected to the amplifier input, the output of the main amplifier or an output of the first peak amplifier. The Doherty amplifier further comprises a first impedance converter connected between the output of the main amplifier and the amplifier output, a second impedance converter connected between the output of the first peak amplifier and an output of the second peak amplifier, and a third impedance converter connected between the output of the second peak amplifier and the amplifier output.

Abstract: A power amplifier (20) for operation in at least a first and a second frequency band, wherein a center frequency f2 of the second frequency band is higher than a center frequency f1 of the first frequency band, is disclosed. The power amplifier (20) comprises a transistor (35) for amplifying an input signal of the power amplifier (20) and an output coupling network (45) for connecting the power amplifier to a resistive load (55). The output coupling network (45) is operatively connected to an output terminal (40) of the transistor (35), has an output terminal (50) for connection to said resistive load (55), and is configured such that, when the power amplifier (20) is connected to said resistive load (55), the power amplifier (20) is arranged to operate in class F for frequencies in one of the first and the second frequency bands, and operate in inverse class F for frequencies in the other one of the first and the second frequency band.