Abstract: A radio frequency power amplifier includes: a transistor configured to amplify a signal at a selected signal frequency; a first line connected to an output of the transistor and disposed on a printed circuit board; and a second line and a third line branched from a rear stage of the first line and disposed on the printed circuit board. The second line is configured to set impedance for the selected signal frequency or a double-wave frequency of the selected signal frequency.

Abstract: There is provided a high frequency switch capable of suppressing deterioration in distortion characteristics. The high frequency switch includes: a common port outputting a transmission signal to an antenna; a plurality of transmission ports each having the transmission signal input thereto; and a plurality of switching units each connected between the plurality of transmission ports and the common port to conduct or block the transmission signal from each of the transmission ports to the common port, wherein each of the switching units has one or more metal oxide semiconductor field effect transistors (MOSFETs) formed on a silicon substrate, and a capacitor connected between a body terminal of a MOSFET connected to the common port among the MOSFETs and a terminal of the MOSFET connected to the common port.

Abstract: There is provided a power amplifier capable of compensating for a distortion without deteriorating a gain of input voltage. The power amplifier includes an input terminal to which an input voltage is applied; a class AB power amplification circuit connected to the input terminal; and an element connected between the input terminal and the class AB power amplification circuit, turned on when the input voltage is equal to or greater than a predetermined value, and varying impedance thereof according to the input voltage.

Abstract: There is provided a high frequency switch capable of suppressing deterioration in distortion characteristics. The high frequency switch includes: a common port outputting a transmission signal to an antenna; a plurality of transmission ports each having the transmission signal input thereto; and a plurality of switching units each connected between the plurality of transmission ports and the common port to conduct or block the transmission signal from each of the transmission ports to the common port, wherein each of the switching units has one or more metal oxide semiconductor field effect transistors (MOSFETs) formed on a silicon substrate, and a capacitor connected between a body terminal of a MOSFET connected to the common port among the MOSFETs and a terminal of the MOSFET connected to the common port.

Abstract: There is provided a high frequency switching circuit that can reduce generation of a harmonic signal without using a boost circuit.

Abstract: Disclosed is a switch circuit capable of reducing distortion caused by harmonics and preventing an increase in insertion loss even if the number of ports increases. The switching circuit includes one common output port, M first switches having one set of ends connected in common to a first node (M?2 where M is a constant), N second switches having one set of ends connected in common to the common output port (N?1 where N is a constant), a third switch having one end connected to the common output port and the other end connected to the first node, M first input ports respectively connected to the other set of ends of the first switches, and N second input ports respectively connected to the other set of ends of the second switches. One selected among the first input ports and the second input ports is connected to the common output port, and if one of the first input ports is selected, the third switch is closed.

Abstract: There is provided a high frequency switching circuit that can reduce generation of a harmonic signal without using a boost circuit.

Abstract: Disclosed is a switch circuit capable of reducing distortion caused by harmonics and preventing an increase in insertion loss even if the number of ports increases. The switching circuit includes one common output port, M first switches having one set of ends connected in common to a first node (M?2 where M is a constant), N second switches having one set of ends connected in common to the common output port (N?1 where N is a constant), a third switch having one end connected to the common output port and the other end connected to the first node, M first input ports respectively connected to the other set of ends of the first switches, and N second input ports respectively connected to the other set of ends of the second switches. One selected among the first input ports and the second input ports is connected to the common output port, and if one of the first input ports is selected, the third switch is closed.

Abstract: Disclosed is a power amplifier, which can lessen distributive and synthetic losses, minimize the size and realize a high effective signal wave thereof. The power amplifier comprises phase converters allocated at front and rear ends of the amplifying elements to include inductors employing an air core coil having a high Q value in a high frequency band, where the phase converter located at the front end of the amplifying elements distributes an input signal to an antiphase signal with the same oscillating width so as to be amplified by the amplifying elements, and the phase converter located at the rear end of the amplifying elements synthesizes and outputs the antiphase signal amplified by the amplifying elements.