High-frequency limiter and switch-limiter circuit having improved recovery time

A high-frequency switch-limiter circuit, said switch-limiter circuit having at least one input port and a high-frequency signal path between said input port and a common arm, comprising:

• input diode means for generating a first bias current in response to incidence upon said input port of high-energy signals in excess of a predefined power level;
• protection diode means for reflecting said high-energy signals upon being switched to an ON state by a portion of said first bias current and for isolating said high-frequency signal path from said common arm when switched to said ON state by a second bias current, said protection diode means being disposed to reflect signal energy propagated by said high-frequency signal path when in said ON state and to pass signal energy propagated by said high-frequency signal path when in an OFF state;
• and
• driver means for providing said first and second bias currents to said protection diode means, said driver means further including means for modifying the impedance of a bias network included so as to expedite switching of said protection diode means between said ON and OFF states.

A high-frequency switch-limiter circuit, said switch-limiter circuit having a plurality of high-frequency branch arms interposed between separate input ports and a common arm, comprising:

• input diode means for generating a first bias current in response to incidence upon a first of said input ports of high-energy signals in excess of a predefined power level;
• first protection diode means for reflecting said high-energy signals upon being switched to an ON state by a portion of said first bias current, said protection diode means being disposed to reflect signal energy propagated by a first of said high-frequency signal paths coupled to said first input port when in said ON state and to pass signal energy propagated by said first high-frequency signal path when in an OFF state;
• second protection diode means for isolating said first high-frequency signal path from said common arm when driven by a second bias current;
• and,
• driver means for providing said portion of said first bias current to said first protection diode means and for providing said second bias current to said second protection diode means, said driver means including means for modifying impedance of a bias network included therein so as to expedite switching of said first protection diode means between said ON and OFF states.

A high-frequency switch-limiter circuit, said switch-limiter circuit having at least a first input port and a high-frequency signal path between said first input port and a common arm, comprising:

• input diode means for generating a first bias current in response to incidence upon said first input port of high-energy signals in excess of a predefined power level;
• a plurality of shunt-connected protection diodes connected in parallel with said high-frequency signal path for reflecting said high-energy signals upon being switched to an ON state by a portion of said first bias current;
• a series-connected protection diode connected in series with said high-frequency signal path wherein said series-connected diode presents a low impedance when driven by a second bias current and a high impedance otherwise;
• and
• driver means for modifying impedance of a bias network included therein so as to expedite switching of said shunt-connected protection diodes between said ON and OFF states, and for driving said series-connected diode with said second bias current.

In a high-frequency limiter circuit having an input port, an output port, a high-frequency signal path therebetween, and a plurality of protection diodes connected to said high-frequency signal path, a method of attenuating high-energy signals comprising the steps of:

• generating a bias current in response to incidence upon said input port of high-energy signals in excess of a predefined power level by a biasing network;
• reflecting said high-energy signals by providing a portion of said bias current to said plurality of protection diodes, said protection diodes being disposed to reflect signal energy propagated by said high-frequency signal path when in an ON state and to pass signal energy propagated by said high-frequency signal path when in an OFF state;
• and
• modifying impedance of said bias network connected to said protection diodes so as to expedite switching of said protection diode means between said ON and OFF states.

In a high-frequency switch-limiter circuit having an input port, an output port, a high-frequency signal path therebetween, and a plurality of protection diodes connected to said high-frequency signal path, a method of attenuating high-energy signals comprising the steps of:

• generating a bias current in response to incidence upon said input port of high-energy signals in excess of a predefined power level by a biasing network;
• placing said protection diodes in an ON state by providing thereto a portion of said first bias current or by providing thereto a second bias current in response to a switch control signal, said protection diodes being disposed to reflect said high-energy signals propagated by said high-frequency signal path when in said ON state and to pass signal energy propagated by said high-frequency signal path when in an OFF state;
• and
• modifying impedance of said bias network connected to said protection diodes so as to expedite switching of said protection diode means between said ON and OFF states.