US4274047A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Analyzer for nonlinear networks
Assignee: AT&T Inc
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Filing: 1979-12-07
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Granted: 1981-06-16
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Expires: 1999-12-07
Abstract
Abstract This application describes a method and apparatus for measuring the transmission characteristics of a class of nonlinear two-ports containing physically inseparable reactive networks, but which can be characterized by an equivalent network comprising input and output linear reactive networks separated by a resistive nonlinear network. In accordance with the method, three signals, f 1 , f 2 and f 3 , are applied to the test network where signals f 2 and f 3 are variable and differ by a relatively small amount Δf. So related, the third order intermod frequency, f p =f 1 -f 2 +f 3 , becomes a constant f p =f 1 +Δf. It is further shown that the magnitude of the output voltage V p at frequency f p is proportional to the square of the magnitude of the input network transfer function H A (f).
Inventors
- 👤 Rudolf P. Hecken
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:52
CPC Classifications
G; G01; G01R; G01R27/00; G01R27/28; G01R23/00; G01R23/16; G01R23/20
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
122 words
Apparatus for analyzing a two-port network including an input portion having a transfer characteristic H A (f); an output portion having a transfer characteristic H B (f); and a resistive nonlinear portion therebetween; said apparatus comprising: means (21) for generating a first signal at a frequency f 1 ; means (10, 15, 16) for generating a second signal having a variable frequency f 2 ; means (11, 15, 16) for generating a third signal having a variable frequency f 3 =f 2 ±Δf, where Δf is a fixed frequency difference; means (20) for applying said signals to said two-port; and means (23) for measuring the magnitude of the third order intermodulation distortion generated by said two-port as a function of frequency f.
Claim 2
Dependent Claim
122 words
Apparatus for analyzing a two-port network including an input portion having a transfer characteristic H A (f); an output portion having a transfer characteristic H B (f); and a resistive nonlinear portion therebetween; said apparatus comprising: means (21) for generating a first signal at a frequency f 1 ; means (10, 15, 16) for generating a second signal having a variable frequency f 2 ; means (11, 15, 16) for generating a third signal having a variable frequency f 3 =f 2 ±Δf, where Δf is a fixed frequency difference; means (20) for applying said signals to said two-port; and means (23) for measuring the magnitude of the third order intermodulation distortion generated by said two-port as a function of frequency f.
Claim 3
Dependent Claim
19 words
The apparatus according to claim 1 wherein the intermodulation measurement is made at frequency f p =f 1 +Δf.
Claim 4
Dependent Claim
19 words
The apparatus according to claim 1 wherein the intermodulation measurement is made at frequency f p =f 1 -Δf.
Claim 5
Dependent Claim
23 words
The apparatus according to claim 1 where the measured intermodulation distortion is proportional to the square of the transfer characteristic |H A (f)|.
Claim 6
Dependent Claim
87 words
The apparatus according to claim 1 wherein said second and third signal generating means comprise: a first fixed frequency oscillator (10); a second fixed frequency oscillator (11); a variable frequency oscillator (16); and a mixer (15); means (14) for combining the signals from said first and second oscillators (10, 11) and for coupling said combined signals to said mixer (15); means for coupling said variable frequency oscillator (16) to said mixer (15); and means for extracting signals at frequencies f 2 and f 3 from said mixer.
Claim 7
Dependent Claim
104 words
The apparatus according to claim 1 wherein said second and third signal generating means comprise: a first fixed frequency oscillator (10); a second fixed frequency oscillator (11); and a variable frequency oscillator (16); a first mixer (32) coupled to said first oscillator (10) and said variable frequency oscillator (16) for generating said second signal having a variable frequency f 2 ; a second mixer (33) coupled to said second oscillator (11) and said variable frequency oscillator (16) for generating said third signal having a variable frequency f 3 ; and means (14) for combining said second and third signals in a common signal path.
Claim 8
Independent Claim
108 words
A method of analyzing a two-port network including: an input portion having a transfer characteristic H A (f); an output portion having a transfer characteristic H B (f); and a resistive nonlinear portion therebetween; said method including the steps of: applying to said network a first signal at a fixed frequency f 1 , a second signal having a variable frequency f 2 , and a third signal having a variable frequency f 3 =f 2 ±Δf where Δf is a fixed frequency difference; and measuring the magnitude of the intermodulation distortion generated by said network at frequency f p =f 1 ±Δf, as a function of frequency.
Claim 9
Independent Claim
108 words
A method of analyzing a two-port network including: an input portion having a transfer characteristic H A (f); an output portion having a transfer characteristic H B (f); and a resistive nonlinear portion therebetween; said method including the steps of: applying to said network a first signal at a fixed frequency f 1 , a second signal having a variable frequency f 2 , and a third signal having a variable frequency f 3 =f 2 ±Δf where Δf is a fixed frequency difference; and measuring the magnitude of the intermodulation distortion generated by said network at frequency f p =f 1 ±Δf, as a function of frequency.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-06-15 | 1984-12-15 | 1985-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-15 | 1988-12-15 | 1989-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-15 | 1992-12-15 | 1993-06-16 | $7700.00 | Window Closed / Lapsed |