US3619780A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transistor noise measuring apparatus
Assignee: HP Inc
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Filing: 1970-01-02
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Granted: 1971-11-09
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Expires: 1990-01-02
Abstract
Abstract An improved instrument measures noise power generated by a transistor under selected test conditions. Automatic adjustment of gain from the input of the transistor under test through succeeding stages provides an accurate readout of noise generated within the transistor under test.
Inventors
- 👤 Bas Hoeks
- 👤 Paul E Stoft
- 👤 Nobuo Numasaki
- 👤 Haruo Ito
- 👤 Takayuki Sato
- 👤 Knud Knudsen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:19
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/26; G01R31/2646
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
233 words
Transistor noise measuring apparatus comprising: transistor circuit means including input and output circuits disposed to connect to the base, emitter and collector electrodes of a transistor to be tested; a pilot signal source connected to the input circuit of said transistor circuit means for supplying a pilot signal of selected frequency thereto; amplifier means connected to the output circuit of said transistor circuit means and including a signal-controlled attenuator for altering signal transmission therethrough in response to an applied control signal; frequency-generating means connected to the output of said amplifier means for producing an output signal having a frequency proportional to said selected frequency component contained in the output of said amplifier means; mixer means having a first input connected to the output of said amplifier means and having a second input connected to the output of said frequency generating means for producing a resultant signal including a direct-current component and a fluctuating component at an output of the mixer means as the combination of signals applied to the inputs thereof; circuit means responsive to the direct-current component of said resultant signal for applying to said amplifier means a control signal representative of said direct-current component for maintaining a signal transmission through said amplifier means substantially constant as said selected frequency is altered; and means responsive to the fluctuating component of said resultant signal for producing an output indication of the transistor noise.
Claim 2
Dependent Claim
233 words
Transistor noise measuring apparatus comprising: transistor circuit means including input and output circuits disposed to connect to the base, emitter and collector electrodes of a transistor to be tested; a pilot signal source connected to the input circuit of said transistor circuit means for supplying a pilot signal of selected frequency thereto; amplifier means connected to the output circuit of said transistor circuit means and including a signal-controlled attenuator for altering signal transmission therethrough in response to an applied control signal; frequency-generating means connected to the output of said amplifier means for producing an output signal having a frequency proportional to said selected frequency component contained in the output of said amplifier means; mixer means having a first input connected to the output of said amplifier means and having a second input connected to the output of said frequency generating means for producing a resultant signal including a direct-current component and a fluctuating component at an output of the mixer means as the combination of signals applied to the inputs thereof; circuit means responsive to the direct-current component of said resultant signal for applying to said amplifier means a control signal representative of said direct-current component for maintaining a signal transmission through said amplifier means substantially constant as said selected frequency is altered; and means responsive to the fluctuating component of said resultant signal for producing an output indication of the transistor noise.
Claim 3
Dependent Claim
177 words
A transistor noise measuring apparatus as in claim 1 wherein: said frequency-generating means produces a pair of signals at said selected frequency having substantially constant phase angle separation therebetween; said mixer means includes first and second modulators each having an input connected to the output of said amplifier means and each having another input connected to receive respective ones of said pair of signals, each of the first and second modulators producing a resultant output signal as the combination of the signals applied to the inputs thereof; said circuit means includes a vector signal combining circuit having a pair of inputs connected to respond to the signals at the outputs of the first and second modulators for producing at an output thereof a signal having an amplitude proportional to the square root of the sum of the squares of signals applied to the inputs thereof; and said amplifier means is connected to respond to the direct-current component of the signal at the output of said vector signal combining circuit for maintaining the signal transmission therethrough substantially constant.
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) | 1974-11-08 | 1975-05-10 | 1975-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-08 | 1979-05-10 | 1979-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-08 | 1983-05-10 | 1983-11-09 | $7700.00 | Window Closed / Lapsed |