Abstract: A radio frequency switch may include a common port transmitting and receiving a radio frequency signal, a first switching unit including a plurality of first switch elements connected in series and opening or closing a signal transfer path between a first port inputting and outputting the radio frequency signal and the common port, and a second switching unit having a plurality of second switch elements connected in series and opening or closing a signal transfer path between a second port inputting and outputting the radio frequency signal and the common port. The second switching unit further includes a first filter circuit unit connected to a control terminal of at least one second switch element among the plurality of second switch elements to remove at least one preset frequency band signal.

Abstract: A radio frequency switch circuit may include a first switch circuit unit connected between a signal port and an antenna port, a second switch circuit unit connected between the signal port and a ground, and a third switch circuit unit connected between the antenna port and the ground. An operation reference voltage of the third switch circuit unit is lower than an operation reference voltage of the first switch circuit unit.

Abstract: A radio frequency switch circuit may include: a first switch circuit unit connected between a first signal port for transmitting and receiving a signal and a common connection node and operated by a first gate signal; a second switch circuit unit connected between a second signal port for transmitting and receiving a signal and the common connection node and operated by a second gate signal; a first shunt circuit unit including first and second shunt units connected to each other in series between a first connection node connected to the first signal port and a ground, the first shunt unit being operated by the first gate signal and the second shunt unit being operated by the second gate signal; and a second shunt circuit unit connected between a second connection node connected to the second signal port and the ground and operated by the first gate signal.

Abstract: A radio frequency switch circuit, according to examples, includes a switching circuit controlled to be in a turned on or turned off state on the basis of a gate signal to thereby allow a radio frequency signal to pass or be blocked; a voltage dividing circuit connected to terminals of the switching circuit that the radio frequency signal passes through and outputting intermediate voltage between the terminals by a voltage dividing node; and an impedance circuit connected between the voltage dividing node and a body terminal of the switching circuit.

Abstract: A low-drop-output type voltage regulator may include an error amplifier providing a gate signal depending on a voltage difference between a reference voltage and a feedback voltage, a semiconductor switch adjusting a current between an input terminal receiving a battery voltage and a ground, in response to the gate signal, a feedback circuit dividing and detecting a detection voltage in a detection node between the semiconductor switch and the ground and providing the feedback voltage, a voltage sensor sensing the battery voltage, and a feedback voltage controller adjusting a level of the feedback voltage depending on the sensed battery voltage.

Abstract: A radio frequency switch circuit may include a first switch circuit unit connected between a signal port and an antenna port, a second switch circuit unit connected between the signal port and a ground, and a third switch circuit unit connected between the antenna port and the ground. An operation reference voltage of the third switch circuit unit is lower than an operation reference voltage of the first switch circuit unit.

Abstract: A voltage dropping apparatus may include: a voltage dropping unit receiving an input voltage, outputting the input voltage in a first mode, and dropping a level of the input voltage in a second mode; a voltage output unit connected to the voltage dropping unit, receiving and outputting the input voltage in the first mode, and receiving and outputting the dropped voltage in the second mode; and a control unit receiving a mode signal and controlling a mode change of the voltage dropping unit and the voltage output unit based on a value of the mode signal.

Abstract: A low-drop-output type voltage regulator may include an error amplifier providing a gate signal depending on a voltage difference between a reference voltage and a feedback voltage, a semiconductor switch adjusting a current between an input terminal receiving a battery voltage and a ground, in response to the gate signal, a feedback circuit dividing and detecting a detection voltage in a detection node between the semiconductor switch and the ground and providing the feedback voltage, a voltage sensor sensing the battery voltage, and a feedback voltage controller adjusting a level of the feedback voltage depending on the sensed battery voltage.

Abstract: A radio frequency switch circuit may include: a first switch circuit unit connected between a first signal port for transmitting and receiving a signal and a common connection node and operated by a first gate signal; a second switch circuit unit connected between a second signal port for transmitting and receiving a signal and the common connection node and operated by a second gate signal; a first shunt circuit unit including first and second shunt units connected to each other in series between a first connection node connected to the first signal port and a ground, the first shunt unit being operated by the first gate signal and the second shunt unit being operated by the second gate signal; and a second shunt circuit unit connected between a second connection node connected to the second signal port and the ground and operated by the first gate signal.

Abstract: A radio frequency (RF) switching circuit may include: a first switching circuit unit connected between a first signal port for signal transmission and reception and a common connection node connected to an antenna port and operated according to a first gate signal; a second switching circuit unit connected between a second signal port for signal transmission and reception and the common connection node and operated according to a second gate signal; a negative voltage generating unit generating a negative voltage using a voltage of an RF signal from the common connection node; and a gate signal generating unit generating the first and second gate signals using the negative voltage from the negative voltage generating unit and an operating voltage.

Abstract: A radio frequency switching circuit may include a first switching circuit unit including first to nth (n is a natural number greater than at least 2) transistors M1 to Mn connected in series between a first signal port for transmission and reception of signals and a common connection node connected to an antenna port and operated according to a first gate signal; a second switching circuit unit connected in series between the common connection node and a second signal port for transmission and reception of signals and operated according to a second gate signal; and a first impedance adjuster forming an alternating current (AC) ground path between a ground and a gate of the first transistor of the first switching circuit unit when the first switching circuit unit is in an off-state.

Abstract: A RF switch may include: a common port coupled to an antenna to transmit and receive first and second high frequency signals; a transmitting switching unit coupled between a transmitting port transferring the first high frequency signal and the common port and including a plurality of switching devices coupled to each other in series; and a receiving switching unit coupled between a receiving port transferring the second high frequency signal and the common port and including a first switching unit including a first switching device. The first switching unit may further include a second switching device having a first terminal coupled to a first terminal of the first switching device and a second terminal coupled to a control terminal of the first switching device.

Abstract: A radio frequency switch may include: a common port transmitting and receiving a radio frequency signal; a receive switch unit including a first switch unit having a plurality of first switch elements and a second switch unit having a plurality of second switch elements; and a transmit switch unit including a third switch unit having a plurality of third switch elements and a fourth switch unit having a plurality of fourth switch elements. The receive switch unit may further include a plurality of first capacitors connected between a first terminal and a body terminal of each of the plurality of first switch elements. The transmit switch unit may further include a plurality of second capacitors connected between a second terminal and a body terminal of each of the plurality of third switch elements.

Abstract: A radio frequency switch may include: a common port transmitting and receiving a radio frequency signal; a receive switch unit including a first switch unit having a plurality of first switch elements and a second switch unit having a plurality of second switch elements; and a transmit switch unit including a third switch unit having a plurality of third switch elements and a fourth switch unit having a plurality of fourth switch elements. The receive switch unit may further include a plurality of first capacitors connected between a first terminal and a body terminal of each of the plurality of first switch elements. The transmit switch unit may further include a plurality of second capacitors connected between a second terminal and a body terminal of each of the plurality of third switch elements.

Abstract: A radio frequency switch may include a common port transmitting and receiving a radio frequency signal, a first switching unit including a plurality of first switch elements connected in series and opening or closing a signal transfer path between a first port inputting and outputting the radio frequency signal and the common port, and a second switching unit having a plurality of second switch elements connected in series and opening or closing a signal transfer path between a second port inputting and outputting the radio frequency signal and the common port. The second switching unit further includes a first filter circuit unit connected to a control terminal of at least one second switch element among the plurality of second switch elements to remove at least one preset frequency band signal.

Abstract: A radio frequency (RF) switching circuit may include: a first switching circuit unit connected between a first signal port for signal transmission and reception and a common connection node connected to an antenna port and operated according to a first gate signal; a second switching circuit unit connected between a second signal port for signal transmission and reception and the common connection node and operated according to a second gate signal; a negative voltage generating unit generating a negative voltage using a voltage of an RF signal from the common connection node; and a gate signal generating unit generating the first and second gate signals using the negative voltage from the negative voltage generating unit and an operating voltage.

Abstract: A radio frequency (RF) switch may include: a common port; a first switching unit; and a second switching unit. The first switching unit further includes a third switching device having one end coupled to a body of one of the plurality of first switching devices and the other end coupled to a first ground terminal, and the second switching unit further includes a fourth switching device having one end coupled to a body of one of the plurality of second switching devices and the other end coupled to a second ground terminal.

Abstract: A RF switch may include: a common port coupled to an antenna to transmit and receive first and second high frequency signals; a transmitting switching unit coupled between a transmitting port transferring the first high frequency signal and the common port and including a plurality of switching devices coupled to each other in series; and a receiving switching unit coupled between a receiving port transferring the second high frequency signal and the common port and including a first switching unit including a first switching device. The first switching unit may further include a second switching device having a first terminal coupled to a first terminal of the first switching device and a second terminal coupled to a control terminal of the first switching device.

Abstract: A radio frequency switching circuit may include a first switching circuit unit including first to nth (n is a natural number greater than at least 2) transistors M1 to Mn connected in series between a first signal port for transmission and reception of signals and a common connection node connected to an antenna port and operated according to a first gate signal; a second switching circuit unit connected in series between the common connection node and a second signal port for transmission and reception of signals and operated according to a second gate signal; and a first impedance adjuster forming an alternating current (AC) ground path between a ground and a gate of the first transistor of the first switching circuit unit when the first switching circuit unit is in an off-state.

Abstract: Disclosed herein is a circuit for preventing an element from being damaged although output impedance of a final transistor is changed in a power amplifier. The power amplifier includes: a power stage amplifying a signal; a transformer connected to an output terminal of the power stage and coupling a signal output from the power stage; and a controller controlling a bias voltage from the power stage according to the coupled signal. Although output impedance is changed, damage to the power amplifier can be prevented. Also, the power amplifier can be automatically controlled to maintain performance thereof by sensing an operational state in which output impedance is normal.