Transmit/receive switch for phased array antenna

A transmit/receive switch comprising:

• a .pi. network means for providing a phase delay in a range of 30 degrees to 60 degrees to an input signal at an input port of said switch in accordance with a control signal applied thereto, said .pi. network means comprising an input branch connected to said input port, an output branch connected to an output port of said switch and a series branch connected between said input port and said output port;
• said input branched of said .pi. network means comprising a resistor and a capacitor in parallel having one end coupled to said input signal at said input port;
• a first switching means coupled between the other end of said resistor and capacitor in parallel and ground in said input branch for enabling a transmit mode of operation of said transmit/receive switch in accordance with a first state of said control signal being coupled to a control terminal of said first switching means;
• a second switching means in said output branch of said .pi. network means and coupled between said output port of said .pi. network means and ground for enabling a receive mode of operation of said transmit/receive switch in accordance with a second state of said control signal being coupled to a control terminal of said second switching means;
• and
• said series branch of said .pi. network means comprises an inductor coupled between said input port and said output port of said transmit/receive switch.

A method of providing a transmit/receive switch for a phase array antenna comprising the steps of:

• providing a .pi. network means to generate a total phase delay in a range of 30 degrees to 60 degrees by said transmit/receive switch to an input signal in accordance with a control signal, said .pi. network means comprising an input branch coupled to an input port of said switch, an output branch coupled to an output port of said switch and a series branch coupled between said input port and said output port;
• providing in said input branch of said .pi. network means, a resistor and a capacitor in parallel with one end connected to said input signal at said input port and a first switching means connected between the other end of said resistor and capacitor in parallel and ground for enabling a transmit mode of operation of said transmit/receive switch in accordance with said control signal connected to a control terminal of said first switching means;
• providing in said output branch of said .pi. network means a second switching means connected between an output port of said switch and ground for enabling a receive mode of operation of said transmit/receive switch in accordance with said control signal connected to a control terminal of said second switching means;
• and
• providing a series branch of said .pi. network having an inductor connected between said input port and said output port of said switch.

A method of providing a transmit/receive switch for a phased array antenna comprising the steps of:

• coupling a control signal to a control input of said transmit/receive switch for selectively placing said switch in one of two modes, a first state of said control signal selecting a transmit mode of said switch and a second state of said control signal selecting a receive mode of said switch;
• electrically connecting a termination impedance to an input port of said transmit/receive switch so as to match a source impedance of an RF input signal coupled to an input port of said switch in response to said first state of said control signal, said transmit/receive switch providing a phase delay in a range of 30 degrees to 60 degrees to said RF input signal;
• and
• electrically disconnecting said termination impedance from said input port with a switching means coupled between said control input and said input port in response to a second state of said control signal thereby enabling a minimal loss path for said RF input signal to pass through said transmit/receive switch to an output port.