Switching circuit, switching module and method of controlling the switching circuit
AssigneeFujitsu Quantum Devices Limited
InventorsTakayuki Kitazawa, Naoyuki Miyazawa
Life of this patent
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Abstract
A switching circuit includes switching transistors connected to one of an input terminal and an output terminal of the switching circuit, and a control bias supply circuit that supplies a control bias for cutting off all the switching transistors to the switching transistors when all of the switching transistors are in a non-selected state.
Claims18
A switching circuit comprising:
- switching transistors commonly connected to a connection node used as one of a high frequency signal input terminal and a high frequency signal output terminal of the switching circuit;
- and
- a control bias supply circuit that supplies a control bias for cutting off all the switching transistors to one of a source and a drain of each of the switching transistors in order to prevent high frequency signal from substantially propagating through all the switching transistors when all of the switching transistors are in a non-selected state in which all the switching transistors are turned OFF in response to selection control signals applied to gates of all the switching transistors,
- wherein the control bias supply circuit comprises a diode having an anode to which a voltage signal is applied from outside of the switching circuit and having a cathode via which the control bias is output in accordance with the voltage signal.
A switching circuit comprising:
- switching transistors commonly connected to a connection node used as one of a high frequency signal input terminal and a high frequency signal output terminal of the switching circuit and
- a control bias supply circuit that supplies a control bias for cutting off all the switching transistors to one of a source and a drain of each of the switching transistors in order to prevent high frequency signal from substantially propagating through all the switching transistors when all of the switching transistors are in a non-selected state in which all the switching transistors are turned OFF in response to selection control signals applied to gates of all the switching transistors, wherein:
- the control bias supply circuit comprises a bias transistor including a structure of a MESFET (metal semiconductor field effect transistor);
- and
- the MESFET having a gate receiving a voltage signal, a first terminal connected to a given potential via a capacitive element, and a second terminal connected to the connection node.
A method of controlling a switching circuit including switching transistors commonly connected to a connection node used as one of a high frequency signal input terminal and a high frequency signal output terminal of the switching circuit, comprising a step of:
- supplying a control bias for cutting off all the switching transistors to one of a source and a drain of each of the switching transistors via a diode in order to prevent high frequency signal from substantially propagating through all the switching transistors when all of the switching transistors are in a non-selected state in which all the switching transistors are turned OFF in response to selection control signals applied to gates of all the switching transistors,
- wherein the diode has an anode to which a voltage signal is applied from outside of the switching circuit, and a cathode via which the control bias is output in accordance with the voltage signal.
Dependencies are inferred from the claim text.