Switch circuit and spdt switch circuit

A switch circuit comprising:

• a MOS transistor transferring or blocking a signal according to a turn on/off operation thereof;
• a gate resistor connected to a gate of the MOS transistor;
• and
• a variable gate resistor circuit decreasing a resistance value of the gate resistor when the MOS transistor is changed from a turn-on state to a turn-off state.

An SPDT circuit comprising:

• an antenna;
• a first MOS transistor group transmitting a transmission signal from a transmitting end to the antenna according to a turn-on operation thereof and blocking introduction of a reception signal received in the antenna into the transmitting end according to a turn-off operation thereof;
• a first gate resistor group including gate resistors each connected to gates of the respective transistors of the first MOS transistor group;
• a second MOS transistor group applied with gate power complementary to turn-on gate power of the first MOS transistor group to operate complementarily to the first MOS transistor group, transferring the reception signal to a receiving end, and blocking leakage of the transmission signal to the receiving end;
• a second gate resistor group including gate resistors each connected to gates of the respective transistors of the second MOS transistor group;
• and
• a variable gate resistor circuit group increasing resistance values of the respective gate resistors when each of the first and second MOS transistor groups is changed from a turn-off state to a turn-on state.

An SPDT circuit comprising:

• an antenna;
• a first MOS transistor group transmitting a transmission signal from a transmitting end to the antenna according to a turn-on operation thereof and blocking introduction of a reception signal received in the antenna into the transmitting end according to a turn-off operation thereof;
• a first gate resistor group including gate resistors each connected to gates of the respective transistors of the first MOS transistor group;
• a second MOS transistor group applied with gate power complementary to turn-on gate power of the first MOS transistor group to operate complementarily to the first MOS transistor group, transferring the reception signal to a receiving end, and blocking leakage of the transmission signal to the receiving end;
• a second gate resistor group including gate resistors each connected to gates of the respective transistors of the second MOS transistor group;
• and
• a variable gate resistor circuit group decreasing resistance values of the respective gate resistors when each of the first and second MOS transistor groups is changed from a turn-on state to a turn-off state.