Transmit/receive switch device

An integrated transmit/receive switch device, comprising:

• a substrate;
• an antenna port to couple with an antenna;
• a transmitter port to couple with a transmitter;
• a receiver port to couple with a receiver;
• a receive path between the antenna port and the receiver port;
• a transmit path between the antenna port and the transmitter port, the transmit path including a first transistor on the substrate, the first transistor coupled in series between the antenna port and the transmitter port;
• an isolation network coupled between a drain of the first transistor and a source of the first transistor, wherein the isolation network is configured to present a high impedance, at least at a frequency range of operation of the receiver;
• and
• a second transistor on the substrate, the second transistor coupled in series between the receiver port and a reference voltage.

An integrated transmit/receive switch device, comprising:

• a substrate;
• an antenna port to couple with an antenna;
• a transmitter port to couple with a transmitter;
• a receiver port to couple with a receiver;
• a receive path between the antenna port and the receiver port;
• a transmit path between the antenna port and the transmitter port, the transmit path including a first transistor on the substrate, the first transistor coupled in series between the antenna port and the transmitter port;
• a second transistor on the substrate, the second transistor coupled in series between the receiver port and a reference voltage;
• a diode circuit coupled between a drain of the second transistor and the reference voltage;
• and
• a biasing circuit to bias the diode circuit when the second transistor is on.

A communication device, comprising:

• a transmitter having an output;
• a power amplifier having an input coupled to the output of the transmitter, and having an output;
• a low noise amplifier having an input and an output;
• a receiver having an input coupled to the output of the low noise amplifier;
• an antenna;
• a transmit/receive switch having a first port coupled to the input of the low noise amplifier, a second port coupled to the output of the power amplifier, and a third port coupled to the antenna, wherein the transmit/receive switch comprises:
• a substrate;
• a receive path between the third port and the first port;
• a transmit path between the third port and the second port, the transmit path including a first transistor on the substrate, the first transistor coupled in series between the third port and the second port, wherein a body node of the first transistor is unconnected, and wherein the substrate is configured to provide a high impedance path from the first transistor to a reference voltage;
• a second transistor on the substrate, the second transistor coupled in series between the first port and the reference voltage.

A communication device, comprising:

• a transmitter having an output;
• a power amplifier having an input coupled to the output of the transmitter, and having an output;
• a low noise amplifier having an input and an output;
• a receiver having an input coupled to the output of the low noise amplifier;
• an antenna;
• a transmit/receive switch having a first port coupled to the input of the low noise amplifier, a second port coupled to the output of the power amplifier, and a third port coupled to the antenna, wherein the transmit/receive switch comprises:
• a substrate;
• a receive path between the third port and the first port;
• a transmit path between the third port and the second port, the transmit path including a first transistor on the substrate, the first transistor coupled in series between the third port and the second port;
• an isolation network coupled between a drain of the first transistor and a source of the first transistor, wherein the isolation network is configured to present a high impedance, at least at a frequency range of operation of the receiver;
• and
• a second transistor on the substrate, the second transistor coupled in series between the first port and a reference voltage.

A communication device, comprising:

• a transmitter having an output;
• a power amplifier having an input coupled to the output of the transmitter, and having an output;
• a low noise amplifier having an input and an output;
• a receiver having an input coupled to the output of the low noise amplifier;
• an antenna;
• a transmit/receive switch having a first port coupled to the input of the low noise amplifier, a second port coupled to the output of the power amplifier, and a third port coupled to the antenna, wherein the transmit/receive switch comprises:
• a substrate;
• a receive path between the third port and the first port;
• a transmit path between the third port and the second port, the transmit path including a first transistor on the substrate, the first transistor coupled in series between the third port and the second port;
• a second transistor on the substrate, the second transistor coupled in series between the receiver port and a reference voltage;
• a diode circuit coupled between a drain of the second transistor and the reference voltage;
• and
• a biasing circuit to bias the diode circuit when the second transistor is on.