Abstract: A radio-frequency (RF) splitter is provided. The RF splitter includes a common branch node configured to transfer an RF signal, input from an input port, to at least one of first and second output ports, first and second branch nodes electrically connected between the common branch node and the first and second output ports, first and second series switches configured to control switching operations to electrically connect the common branch node and the first and second branch nodes to each other, first and second inductors electrically connected between the common branch node and the first and second branch nodes, a resistor electrically connected between the first and second branch nodes, and first and second shunt switches configured to control switching operations to electrically connect the first and second branch nodes and the resistor to each other.

Abstract: A front-end module is provided. The front-end module includes a reception amplifier configured to amplify a received radio-frequency (RF) signal, first and second series switches configured to control a switching operation to electrically connect an output terminal of the reception amplifier and first and second reception ports to each other, a radio-frequency (RF) splitter configured to simultaneously transfer a received RF signal, amplified by the reception amplifier or bypassing the reception amplifier, to the first and second reception ports, first and second shunt switches configured to control a switching operation to electrically connect a ground and first and second branch nodes between the RF splitter and the first and second reception ports to each other, and first and second reflected wave removing impedance elements electrically connected between the first and second branch nodes and a ground.

Abstract: A radio-frequency (RF) splitter is provided. The RF splitter includes a common branch node configured to transfer an RF signal, input from an input port, to at least one of first and second output ports, first and second branch nodes electrically connected between the common branch node and the first and second output ports, first and second series switches configured to control switching operations to electrically connect the common branch node and the first and second branch nodes to each other, first and second inductors electrically connected between the common branch node and the first and second branch nodes, a resistor electrically connected between the first and second branch nodes, and first and second shunt switches configured to control switching operations to electrically connect the first and second branch nodes and the resistor to each other.

Abstract: A front-end module is provided. The front-end module includes a reception amplifier configured to amplify a received radio-frequency (RF) signal, first and second series switches configured to control a switching operation to electrically connect an output terminal of the reception amplifier and first and second reception ports to each other, a radio-frequency (RF) splitter configured to simultaneously transfer a received RF signal, amplified by the reception amplifier or bypassing the reception amplifier, to the first and second reception ports, first and second shunt switches configured to control a switching operation to electrically connect a ground and first and second branch nodes between the RF splitter and the first and second reception ports to each other, and first and second reflected wave removing impedance elements electrically connected between the first and second branch nodes and a ground.

Abstract: A bias circuit includes a bias current circuit varying a resistance value according to a mode voltage determined according to a magnitude of an input radio frequency signal, and generating a bias current that is controlled according to the variation of the resistance value; a bias voltage circuit generating a bias voltage that is adjusted according to a change in a power source voltage and supplying the bias voltage to an amplifying circuit; and a bias transfer circuit supplying the bias current to a base node of the amplifying circuit and blocking an input of the radio frequency signal from the base node.

Abstract: A bias circuit includes a bias current circuit varying a resistance value according to a mode voltage determined according to a magnitude of an input radio frequency signal, and generating a bias current that is controlled according to the variation of the resistance value; a bias voltage circuit generating a bias voltage that is adjusted according to a change in a power source voltage and supplying the bias voltage to an amplifying circuit; and a bias transfer circuit supplying the bias current to a base node of the amplifying circuit and blocking an input of the radio frequency signal from the base node.

Abstract: A low noise amplifier circuit includes a first amplifier including a first transistor and a second transistor that are cascode-connected to each other; a second amplifier including a third transistor and a fourth transistor that are cascode-connected to each other; a source terminal matcher connected to a source of the first transistor and a source of the third transistor; and an input matcher providing input that is impedance-matched by a first inductor and a second inductor to a gate of the first transistor and providing input which is impedance-matched by the first inductor to a gate of the third transistor. The circuit is able to operate in a dual-band and provide impedance matching, while being simpler than alternative circuits.

Abstract: A signal amplifier includes a band suppression filter configured to suppress a preset band among bands included in an input signal, a first common source-type amplifier connected between a supply terminal of a driving voltage and a ground terminal and configured to amplify a first input signal separated from an output signal of the band suppression filter in a common input node to provide a first amplified signal to a common output node, a second common source-type amplifier configured to amplify a second input signal separated from the output signal of the band suppression filter in the common input node to provide a second amplified signal to the common output node, and an output matcher configured to match levels of impedance between the common output node and an output terminal and to transfer a combined signal to the output terminal.

Abstract: A concurrent multi-band RF amplifying circuit may include: an input impedance matching unit performing impedance matching on each of first and second band signals included in an input signal input through one input terminal; an input amplifying unit including first and second band amplifying units each amplifying the first and second band signals input through the input impedance matching unit; a common ground circuit unit connected between a first common node commonly connected to the first and second band amplifying unit and a ground and including an impedance device for matching of an input impedance; and an output amplifying unit amplifying signals from each of the first and second band amplifying units.

Abstract: A signal amplifier may include a first common gate-type amplifying unit connected to a source voltage terminal, dividing an input signal into two signals, amplifying the two divided signals, respectively, and providing a first signal and a second signal, a second common gate-type amplifying unit connected to a ground, dividing the input signal into two signals, amplifying the two divided signals, respectively, and providing a third signal and a fourth signal, a signal summing unit summing the first signal and the second signal from the first common gate-type amplifying unit and the third signal and the fourth signal from the second common gate-type amplifying unit, and an impedance matching unit impedance-matching a signal summed by the signal summing unit.

Abstract: A low noise amplifier circuit includes a first amplifier including a first transistor and a second transistor that are cascode-connected to each other; a second amplifier including a third transistor and a fourth transistor that are cascode-connected to each other; a source terminal matcher connected to a source of the first transistor and a source of the third transistor; and an input matcher providing input that is impedance-matched by a first inductor and a second inductor to a gate of the first transistor and providing input which is impedance-matched by the first inductor to a gate of the third transistor. The circuit is able to operate in a dual-band and provide impedance matching, while being simpler than alternative circuits.

Abstract: A signal amplifier includes a band suppression filter configured to suppress a preset band among bands included in an input signal, a first common source-type amplifier connected between a supply terminal of a driving voltage and a ground terminal and configured to amplify a first input signal separated from an output signal of the band suppression filter in a common input node to provide a first amplified signal to a common output node, a second common source-type amplifier configured to amplify a second input signal separated from the output signal of the band suppression filter in the common input node to provide a second amplified signal to the common output node, and an output matcher configured to match levels of impedance between the common output node and an output terminal and to transfer a combined signal to the output terminal.

Abstract: A signal amplifier may include a first common gate-type amplifying unit connected to a source voltage terminal, dividing an input signal into two signals, amplifying the two divided signals, respectively, and providing a first signal and a second signal, a second common gate-type amplifying unit connected to a ground, dividing the input signal into two signals, amplifying the two divided signals, respectively, and providing a third signal and a fourth signal, a signal summing unit summing the first signal and the second signal from the first common gate-type amplifying unit and the third signal and the fourth signal from the second common gate-type amplifying unit, and an impedance matching unit impedance-matching a signal summed by the signal summing unit.

Abstract: A signal amplifier having an inverted topology may include: a first common source-type amplifying unit connected to a power supply terminal and amplifying a first band signal among input signals; a second common source-type amplifying unit connected to a ground terminal and amplifying a second band signal among input signals; and an output matching unit performing impedance matching with respect to a first band between the first common source-type amplifying unit and an output terminal and performing impedance matching with respect to a second band between the second common source-type amplifying unit and the output terminal. The first common source-type amplifying unit, the output matching unit, and the second common source-type amplifying unit may form a single current path between the power supply terminal and the ground terminal.

Abstract: There is provided a circuit board capable of internally transferring a signal through radio communications. The circuit board according to the present disclosure may include: an insulation layer; a first signal transfer circuit formed of a circuit pattern on one surface of the insulation layer; and a second signal transfer circuit formed of a circuit pattern on the other surface of the insulation layer and wirelessly transferring a signal through resonance with the first signal transfer circuit; wherein the first and second signal transfer circuits transfer the signal in a super high frequency (SHF) band or an extremely high frequency (EHF) band.

Abstract: A concurrent multi-band RF amplifying circuit may include: an input impedance matching unit performing impedance matching on each of first and second band signals included in an input signal input through one input terminal; an input amplifying unit including first and second band amplifying units each amplifying the first and second band signals input through the input impedance matching unit; a common ground circuit unit connected between a first common node commonly connected to the first and second band amplifying unit and a ground and including an impedance device for matching of an input impedance; and an output amplifying unit amplifying signals from each of the first and second band amplifying units.

Abstract: A signal amplifier having an inverted topology may include: a first common source-type amplifying unit connected to a power supply terminal and amplifying a first band signal among input signals; a second common source-type amplifying unit connected to a ground terminal and amplifying a second band signal among input signals; and an output matching unit performing impedance matching with respect to a first band between the first common source-type amplifying unit and an output terminal and performing impedance matching with respect to a second band between the second common source-type amplifying unit and the output terminal. The first common source-type amplifying unit, the output matching unit, and the second common source-type amplifying unit may form a single current path between the power supply terminal and the ground terminal.