US5144266A
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Broadband high frequency active MMIC circulator
Assignee: General Dynamics Mission Systems Inc
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Filing: 1991-02-04
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Granted: 1992-09-01
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Expires: 2011-02-04
Abstract
Abstract A broadband high frequency active MMIC circulator which includes low parasitic devices (MESFETs or HEMTs) and shunt feedback for impedance contouring in conjunction with a cascode/cascade isolation/gain network. To achieve circulation, a common series feedback node is required for each active element. While conventional active circulator topologies require the use of a resistive element for operation with a deleterious effect on noise performance, this broadband high frequency active MMIC circulator functions with either resistive or reactive common series feedback. When reactive feedback is selected, major improvements in noise performance can be realized.
Inventors
- 👤 Richard M. Dougherty
- 👤 Stephen W. Boser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:43
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/38
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
191 words
An active monolithic microwave integrated circuit (MMIC) signal circulator capable of high frequency performance with contourable bandpass characteristics, the active MMIC signal circulator having a plurality of at least three input/output ports and comprising: a first cascode network, wherein the first cascode network comprises a plurality of at least two transistors, the first cascode network including a first node coupled to the first input/output port, a second node coupled to the third input/output port, and a common node; a second cascode network, wherein the second cascode network comprises a plurality of at least two transistors, the second cascode network including a first node coupled to the third input/output port, a second node coupled to the second input/output port, and a common node; a third cascode network, wherein the third cascode network comprises a plurality of at least two transistors, the third cascode network including a first node coupled to the second input/output port, a second node coupled to the first input/output port, and a common node; and common feedback means coupled to each of the common nodes of the first cascode network, the second cascode network, and the third cascode network.
Claim 2
Dependent Claim
191 words
An active monolithic microwave integrated circuit (MMIC) signal circulator capable of high frequency performance with contourable bandpass characteristics, the active MMIC signal circulator having a plurality of at least three input/output ports and comprising: a first cascode network, wherein the first cascode network comprises a plurality of at least two transistors, the first cascode network including a first node coupled to the first input/output port, a second node coupled to the third input/output port, and a common node; a second cascode network, wherein the second cascode network comprises a plurality of at least two transistors, the second cascode network including a first node coupled to the third input/output port, a second node coupled to the second input/output port, and a common node; a third cascode network, wherein the third cascode network comprises a plurality of at least two transistors, the third cascode network including a first node coupled to the second input/output port, a second node coupled to the first input/output port, and a common node; and common feedback means coupled to each of the common nodes of the first cascode network, the second cascode network, and the third cascode network.
Claim 3
Dependent Claim
35 words
An active MMIC signal circulator of three input/output ports as claimed in claim 1 wherein the first cascode network, the second cascode network, and the third cascode network are each coupled to a cascade network.
Claim 4
Dependent Claim
105 words
An active MMIC signal circulator of three input/output ports as claimed in claim 2 wherein each of the cascode networks comprises a plurality of at least a first and a second cascode metal semiconductor field effect transistor (MESFET) wherein the first cascode MESFET comprises: source means coupled to the common nodes of each of the first cascode network, the second cascode network, and the third cascode network; gate means coupled to the third input/output port; and drain means; and the second cascode MESFET comprises; source means coupled to the drain means of the first cascode MESFET; gate means connected to electrical ground; and drain means.
Claim 5
Dependent Claim
65 words
An active MMIC signal circulator of three input/output ports as claimed in claim 3 wherein each of the cascade networks comprises at least one cascade MESFET wherein the cascade MESFET comprises: source means coupled to the common nodes of each of the first cascode network, the second cascode network, and the third cascode network; gate means; and drain means coupled to the first input/output port.
Claim 6
Dependent Claim
91 words
An active MMIC signal circulator of three input/output ports as claimed in claim 4 wherein each cascade network is coupled to a feedback contouring network means comprised of three terminals wherein: the first terminal of the feedback contouring network means is connected to the third input/output port; the second terminal of the feedback contouring network means is connected to the first input/output port; and the third terminal of the feedback contouring network means is coupled in series through an inductive tap to transmission means to the second cascode MESFET drain means.
Claim 7
Dependent Claim
25 words
An active MMIC signal circulator of three input/output ports as claimed in claim 5 wherein the common feedback means comprises at least one reactive element.
Claim 8
Dependent Claim
115 words
A broadband high frequency active monolithic microwave integrated circuit (MMIC) circulator with contourable bandpass characteristics, the broadband high frequency active MMIC circulator comprising: common series feedback means connected to an electrical ground; a plurality of at least three input/output ports; a plurality of at least three isolation/gain means of the same number as and corresponding one for one to the plurality of input/output ports, wherein each isolation/gain means comprises a cascode network and is coupled to the common series feedback means and the plurality of isolation/gain means are electrically connected in a ring configuration alternating with the plurality of input/output ports so that each isolation/gain means is coupled to a unique pair of input/output ports.
Claim 9
Dependent Claim
115 words
A broadband high frequency active monolithic microwave integrated circuit (MMIC) circulator with contourable bandpass characteristics, the broadband high frequency active MMIC circulator comprising: common series feedback means connected to an electrical ground; a plurality of at least three input/output ports; a plurality of at least three isolation/gain means of the same number as and corresponding one for one to the plurality of input/output ports, wherein each isolation/gain means comprises a cascode network and is coupled to the common series feedback means and the plurality of isolation/gain means are electrically connected in a ring configuration alternating with the plurality of input/output ports so that each isolation/gain means is coupled to a unique pair of input/output ports.
Claim 10
Dependent Claim
20 words
A broadband high frequency active MMIC circulator as claimed in claim 7 wherein each isolation/gain means comprises a cascade network.
Claim 11
Dependent Claim
92 words
A broadband high frequency active MMIC circulator as claimed in claim 8 wherein the cascode network comprises a plurality of at least two metal semiconductor field effect transistors (MESFETs) wherein the first MESFET comprises: source means coupled to the common nodes of each of the first isolation/gain means, second isolation/gain means, and the third isolation/gain means; gate means coupled to the third input/output port; and drain means; and the second MESFET comprises: source means coupled to the drain means of the first MESFET; gate means connected to electrical ground; and drain means.
Claim 12
Dependent Claim
50 words
A broadband high frequency active MMIC circulator as claimed in claim 9 wherein the cascade network comprises: source means coupled to the common nodes of each of the first isolation/gain means, second isolation/gain means, and the third isolation/gain means; gate means; and drain means coupled to the first input/output port.
Claim 13
Dependent Claim
100 words
A broadband high frequency active MMIC circulator as claimed in claim 7 wherein the cascode network is coupled to a feedback contouring network means comprised of a first terminal, a second terminal, and a third terminal wherein: the first terminal of the feedback contouring network means is connected to the third input/output port; the second terminal of the feedback contouring network means is connected to the first input/output port; and the third terminal of the feedback contouring network means is coupled in series through an inductive tap to transmission means to the second MESFET drain means of the cascode network.
Claim 14
Dependent Claim
24 words
A broadband high frequency active MMIC circulator as claimed in claim 7 wherein the common series feedback means comprises at least one reactive element.
References Cited (Backward Citations)
US3860893A
Cited
JPH0290713A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-09-01 | 1996-03-02 | 1996-09-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-01 | 2000-03-02 | 2000-09-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-01 | 2004-03-02 | 2004-09-01 | $7700.00 | Window Closed / Lapsed |