Broad band microwave biasing networks suitable for being provided in monolithic integrated circuit form

Claim 2

A circuit for providing an impedance of a controlled magnitude between an input terminal and an output terminal, including in combination: a first diode responsive to changes in bias signals to provide impedances of different magnitudes, said first diode having first and second electrodes coupled between the input terminal and the output terminal; first bias means coupled to said first diode for selectively biasing said first diode in a relatively nonconductive state so that the input terminal is thereby isolated from the output terminal; means for providing control signals; and second bias means including a field effect transistor having first electrode, second electrode and control electrode, said control electrode being coupled to said means for providing control signals to selectively render said field effect transistor conductive, said first electrode being coupled to said first diode for providing bias signals for selectively rendering said first diode relatively conductive in response to said controls signals so that the input terminal is selectively coupled to the output terminal in response to said control signals.

Claim 3

The circuit of claim 1 wherein said first bias means includes resistive means.

Claim 4

The circuit of claim 1 further including bias current return means coupled to said first diode.

Claim 5

The circuit of claim 3 further including: reference conductor means; and said bias current return means includes a further field effect transistor coupled between said first diode and said reference conductor.

Claim 6

The circuit of claim 1 wherein said first diode is a PIN diode; and said field effect transistor is a MESFET so that the circuit is operable at microwave frequencies.

Claim 7

The circuit of claim 4 wherein said MESFET has a multiple gate structure.

Claim 8

The circuit of claim 1 being further adapted to selectively shunt signals occurring at a node, to a reference terminal, said circuit further including in combination: coupling means for coupling the node to said first diode; a second diode having first and second electrodes, said first electrode being coupled to the node and said second electrode being coupled to the reference terminal; a third diode having a first electrode and a second electrode, said second electrode of said third diode being coupled to said node; first power supply conductor means; third bias means coupled between said first power supply conductor means and said first electrode of said third diode; and fourth bias means including a further field effect transistor adapted to selectively provide forward biasing drive signals to said first electrode of said third diode to render said third diode conductive, said third diode thereby rendering said second diode conductive so that the signals applied to said node are coupled to said reference terminal through said second diode.

Claim 9

The circuit of claim 7 wherein said coupling means includes a capacitive means.

Claim 10

The circuit of claim 7 being provided in integrated circuit form.

Claim 11

A switching circuit for selectively connecting signals between a first terminal and a second terminal, said switching circuit including in combination: a first diode having first and second electrodes, said first electrode being coupled to the first terminal and said second electrode being coupled to the second terminal; a second diode having a first electrode and a second electrode, said second electrode of said second diode being coupled to the first terminal; first power supply conductor means; first bias means coupled between said first power supply conductor means and said first electrode of said second diode for rendering said second diode nonconductive; and second bias means including a first field effect transistor adapted to selectively provide forward biasing drive signals to said first electrode of said second diode to render said second diode conductive, said second diode thereby rendering said first diode conductive so that the signals applied to the first terminal are coupled to the second terminal through said first diode.

Claim 12

A switching circuit for selectively connecting signals between a first terminal and a second terminal, said switching circuit including in combination: a first diode having first and second electrodes, said first electrode being coupled to the first terminal and said second electrode being coupled to the second terminal; a second diode having a first electrode and a second electrode, said second electrode of said second diode being coupled to the first terminal; first power supply conductor means; first bias means coupled between said first power supply conductor means and said first electrode of said second diode for rendering said second diode nonconductive; and second bias means including a first field effect transistor adapted to selectively provide forward biasing drive signals to said first electrode of said second diode to render said second diode conductive, said second diode thereby rendering said first diode conductive so that the signals applied to the first terminal are coupled to the second terminal through said first diode.

Claim 13

The switching circuit of claim 10 further including capacitive means coupled to said first terminal.

Claim 14

The switching circuit of claim 10 further adapted for providing a controlled impedance in a path between a first port and a second port, the path being coupled to the first terminal, the switching circuit further including in combination: a third diode included in the path between the first port and the second port, said third diode having first and second electrodes; third bias means coupled to and biasing said third diode in a relatively nonconductive state so that the first port is isolated from the second port; means for providing control signals; fourth bias means coupled to said third diode for selectively rendering said third diode relatively conductive in response to said controls signals so that the first port is then selectively coupled to the second port in response to said control signals, said fourth bias means including a second field effect transistor having first electrode means, second electrode means and control electrode means, said control electrode means being coupled to said means for providing control signals such that said second field effect transistor is rendered conductive to forward bias said third diode; and bias current return means coupled to said third diode.

Claim 15

The switching circuit of claim 12 wherein said first and second field effect transistors include gallium arsenide material.

Claim 16

A variable attenuator circuit for providing a resistance of a controlled magnitude between an input terminal and an output terminal, including in combination: variable resistance means responsive to changes in bias signals to provide resistances of different magnitudes, said variable resistance means having first and second terminals coupled between the input terminal and the output terminal; means for providing control signals; and bias means including a field effect transistor having first electrode, second electrode and a plurality of control electrodes, said control electrodes being coupled to said means for providing control signals to selectively render said field effect transistor conductive, said field effect transistor thereby being responsive to said control signals to provide bias signals of different magnitudes, said first electrode being coupled to said variable resistance means for providing said bias signals thereto for selectively rendering said variable resistance means conductive in response to said controls signals so that the input terminal is selectively coupled to the output terminal in response to said control signals.

Claim 17

A variable attenuator circuit for providing a resistance of a controlled magnitude between an input terminal and an output terminal, including in combination: variable resistance means responsive to changes in bias signals to provide resistances of different magnitudes, said variable resistance means having first and second terminals coupled between the input terminal and the output terminal; means for providing control signals; and bias means including a field effect transistor having first electrode, second electrode and a plurality of control electrodes, said control electrodes being coupled to said means for providing control signals to selectively render said field effect transistor conductive, said field effect transistor thereby being responsive to said control signals to provide bias signals of different magnitudes, said first electrode being coupled to said variable resistance means for providing said bias signals thereto for selectively rendering said variable resistance means conductive in response to said controls signals so that the input terminal is selectively coupled to the output terminal in response to said control signals.

Claim 18

The variable attentuator circuit of claim 14 wherein said variable resistance means includes a first diode having a first electrode and a second electrode.

Claim 19

The variable attentuator circuit of claim 15 further including: reference conductor means; and bias current return means coupled between said first diode and said reference conductor means.

Claim 20

The variable attentuator circuit of claim 14 wherein said variable resistance means includes a first diode having a first electrode and a second electrode, and the variable attenuator circuit further including: reference conductor means; a second diode coupled between said first electrode of said first diode and said reference conductor means; a third diode coupled between said second electrode of said first diode and said reference conductor means; and said diodes responding to said bias signals of different magnitudes to provide resistances of different magnitudes between the input terminal and the output terminal.

Claim 21

The variable attenuator circuit of claim 14 further including: additional bias means coupled to said variable resistance means for selectively biasing said variable resistance means in a relatively nonconductive state so that the input terminal is thereby isolated from the output terminal.

Claim 22

A circuit for providing an impedance of a controlled magnitude between an input terminal and an output terminal, including in combination: a first diode responsive to changes in bias signals to provide impedances of different magnitudes, said first diode having first and second electrodes coupled between the input terminal and the output terminal; means for providing control signals; and bias means including a field effect transistor having first electrode, second electrode and control electrode, said control electrode being coupled to said means for providing control signals to selectively render said field effect transistor conductive, said first electrode being coupled to said first diode for providing bias signals for selectively rendering said first diode relatively conductive in response to said controls signals so that the input terminal is selectively coupled to the output terminal in response to said control signals.

Claim 23

A circuit for providing an impedance of a controlled magnitude between an input terminal and an output terminal, including in combination: a first diode responsive to changes in bias signals to provide impedances of different magnitudes, said first diode having first and second electrodes coupled between the input terminal and the output terminal; means for providing control signals; and bias means including a field effect transistor having first electrode, second electrode and control electrode, said control electrode being coupled to said means for providing control signals to selectively render said field effect transistor conductive, said first electrode being coupled to said first diode for providing bias signals for selectively rendering said first diode relatively conductive in response to said controls signals so that the input terminal is selectively coupled to the output terminal in response to said control signals.

Claim 24

The circuit of claim 19 including further bias means coupled to said first diode for selectively biasing said first diode in a relatively nonconductive state so that the input terminal is thereby selectively isolated from the output terminal.

Claim 25

The circuit of claim 20 wherein said further bias means includes resistive means.

Claim 26

The circuit of claim 19 further including bias current return means coupled to said first diode.

Claim 27

The circuit of claim 22 further including: reference conductor means; and said bias current return means includes a further field effect transistor coupled between said first diode and said reference conductor.

Claim 28

The circuit of claim 19 wherein said first diode is a PIN diode; and said field effect transistor is a MESFET so that the circuit is operable at microwave frequencies.

Claim 29

The circuit of claim 24 wherein said MESFET has a multiple gate structure.

Claim 30

The circuit of claim 19 being further adapted to selectively shunt signals occurring at a node, to a reference terminal, said circuit further including in combination: coupling means for coupling the node to said first diode; a second diode having first and second electrodes, said first electrode being coupled to the node and said second electrode being coupled to the reference terminal; a third diode having a first electrode and a second electrode, said second electrode of said third diode being coupled to said node; and second bias means including a further field effect transistor adapted to selectively provide forward biasing drive signals to said first electrode of said third diode to render said third diode conductive, said third diode thereby rendering said second diode conductive so that the signals applied to said node are coupled to the reference terminal through said second diode.

Claim 31

The circuit of claim 26 wherein said coupling means includes a capacitive means.

Claim 32

The circuit of claim 26 being provided in integrated circuit form.

Claim 33

A variable attenuator circuit for providing a resistance of a controlled magnitude between an input terminal and an output terminal, including in combination: a first diode responsive to changes in bias signals to provide resistances of different magnitudes, said first diode having first and second terminals coupled between the input terminal and the output terminal; first bias means coupled to said first diode for isolated selectively biasing said first diode in a relatively nonconductive state so that the input terminal is thereby isolated from the output terminal; means for providing control signals; and second bias means including a field effect transistor having first electrode, second electrode and control electrode, said control electrode being coupled to said means for providing control signals to selectively render said field effect transistor conductive, said first electrode being coupled to said first diode for providing bias signals thereto for selectively rendering said first diode relatively conductive in response to said control signals so that the input terminal is selectively coupled to the output terminal in response to said control signals.

Claim 34

A variable attenuator circuit for providing a resistance of a controlled magnitude between an input terminal and an output terminal, including in combination: a first diode responsive to changes in bias signals to provide resistances of different magnitudes, said first diode having first and second terminals coupled between the input terminal and the output terminal; first bias means coupled to said first diode for isolated selectively biasing said first diode in a relatively nonconductive state so that the input terminal is thereby isolated from the output terminal; means for providing control signals; and second bias means including a field effect transistor having first electrode, second electrode and control electrode, said control electrode being coupled to said means for providing control signals to selectively render said field effect transistor conductive, said first electrode being coupled to said first diode for providing bias signals thereto for selectively rendering said first diode relatively conductive in response to said control signals so that the input terminal is selectively coupled to the output terminal in response to said control signals.

Claim 35

The variable attenuator circuit of claim 29 further including: reference conductor means; and bias current return means coupled between said first diode and said reference conductor means.

Claim 36

The variable attenuator circuit of claim 29 wherein said field effect transistor has a plurality of gates so that said field effect transistor can respond to said control signals

Claim 37

The variable attenuator circuit of claim 31 wherein further first diode has a first electrode and a second electrode, and the variable attenuator circuit further including: reference conductor means; second diode coupled between said first electrode of said first diode and said reference conductor means; third diode coupled between said second electrode of said first diode and said reference conductor means; and said diodes responding to said bias signals of different magnitudes to provide resistances of different magnitudes between the input terminal and the output terminal.