High power high isolation low current cmos rf switch

A radio frequency (RF) switch, comprising:

• a first transistor having a source, drain and gate, said first transistor operative to couple a transmit signal from a transmitter to a first antenna;
• a second transistor having a source, drain and gate, said second transistor operative to couple said transmit signal from a transmitter to a second antenna;
• a third transistor having a source, drain and gate, said third transistor operative to couple a receive signal from said first antenna to a receiver;
• a fourth transistor having a source, drain and gate, said fourth transistor operative to couple said receive signal from said second antenna to said receiver;
• a control circuit coupled to the source, drain and gate terminals of said first transistor, said second transistor, said third transistor and said fourth transistor, said control circuit operative to generate source, drain and gate signals such that only one of said four transistors is in an on state while placing the remaining three transistors in a reverse bias off state.

A method for use with a radio frequency switch, said method comprising:

• providing a first transistor having a source, drain and gate, said first transistor operative to couple a transmit signal from a transmitter to a first antenna;
• providing a second transistor having a source, drain and gate, said second transistor operative to couple said transmit signal from a transmitter to a second antenna;
• providing a third transistor having a source, drain and gate, said third transistor operative to couple a receive signal from said first antenna to a receiver;
• providing a fourth transistor having a source, drain and gate, said fourth transistor operative to couple said receive signal from said second antenna to said receiver;
• generating source, drain and gate signals for said first transistor, said second transistor, said third transistor and said fourth transistor, such that only one of said four transistors is in an on state while the remaining three transistors are in a reverse bias off state;
• wherein a transistor is placed in an on state by forward biasing its gate-source junction;
• and
• wherein a transistor is placed in an off state by reverse biasing its gate-source junction.

A wireless communication device, comprising:

• a first antenna;
• a second antenna;
• a transmitter;
• a receiver;
• an RF switch;
• said RF switch comprising:
• a first transistor operative to couple a transmit signal from said transmitter to said first antenna;
• a second transistor operative to couple said transmit signal from a transmitter to said second antenna;
• a third transistor operative to couple a receive signal from said first antenna to said receiver;
• a fourth transistor operative to couple said receive signal from said second antenna to said receiver;
• and
• a control circuit coupled to said first transistor, said second transistor, said third transistor and said fourth transistor, said control circuit operative to place only one of said four transistors in an on state while placing the remaining three transistors in a reverse biased off state.