Patent US3859601A successfully refreshed from Google Patents.
US3859601A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signal handling arrangement and frequency diversity combining arrangements utilising the same
Assignee: BAE Systems Electronics Ltd
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Filing: 1973-04-11
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Granted: 1975-01-07
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Expires: 1993-04-11
Abstract
Abstract A signal handling arrangement for use in a diversity predetection combining arrangement in which input signals are fed in parallel to two balanced mixers. The output from one mixer feeds a second input of the other mixer through a band pass filter which passes one sideband and the output from the second mixer feeds a second input of the first mixer through a filter capable of tracking in response to the frequency of the input signals applied to it so as to maintain passage of signals in the sideband of the output from the second mixer which corresponds to the sideband passed by the first filter thereby alleviating problems due to phase shifting between outputs from two identical frequency diverse arrangements.
Inventors
- 👤 Anthony Thomas Curtis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:08
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/02; H04B7/12
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
255 words
A signal handling arrangement suitable for use in a frequency diversity predetection combining arrangement comprising two balanced mixers, means for applying input signals in parallel to both mixers, means for deriving a second input for one of said mixers from the output of the other via band pass filter means adapted to pass signals in one of the sidebands of the output from said other mixer, further band pass filter means connected to apply output from said one mixer as a second input for said other mixer, and output means for taking output signals from the output of said first mentioned band pass filter means wherein said further band pass filter means is capable of tracking in response to the frequency of input signals applied thereto over a range of frequencies so as to maintain passage of signals in the sideband of the output from said one mixer which corresponds to said one sideband of the output of said other mixer and comprises a phase locked loop circuit connected to apply output from said one mixer as a second input to said other mixer and as one input to a further balanced mixer, a second input for which is derived via a 90* phase shifter from the output of said one balanced mixer, means being provided for utilising output from said further balanced mixer to control the attenuation provided by a linearly variable attenuator connected in the path between said first mentioned band pass filter means and both said one mixer and said output means.
Claim 2
Dependent Claim
255 words
A signal handling arrangement suitable for use in a frequency diversity predetection combining arrangement comprising two balanced mixers, means for applying input signals in parallel to both mixers, means for deriving a second input for one of said mixers from the output of the other via band pass filter means adapted to pass signals in one of the sidebands of the output from said other mixer, further band pass filter means connected to apply output from said one mixer as a second input for said other mixer, and output means for taking output signals from the output of said first mentioned band pass filter means wherein said further band pass filter means is capable of tracking in response to the frequency of input signals applied thereto over a range of frequencies so as to maintain passage of signals in the sideband of the output from said one mixer which corresponds to said one sideband of the output of said other mixer and comprises a phase locked loop circuit connected to apply output from said one mixer as a second input to said other mixer and as one input to a further balanced mixer, a second input for which is derived via a 90* phase shifter from the output of said one balanced mixer, means being provided for utilising output from said further balanced mixer to control the attenuation provided by a linearly variable attenuator connected in the path between said first mentioned band pass filter means and both said one mixer and said output means.
Claim 3
Dependent Claim
39 words
An arrangement as claimed in claim 1 and wherein said linearly variable attenuator is a PIN diode attenuator and control signals from said further balanced mixer are passed to said PIN diode attenuator via an amplifying low pass filter.
Claim 4
Dependent Claim
20 words
An arrangement as claimed in claim 1 and wherein the sideband of the outputs of the mixers are lower sidebands.
Claim 5
Dependent Claim
51 words
A frequency diversity signal combining arrangement comprising a plurality of signal handling arrangements each as claimed in claim 1, one for each frequency diversity signal channel to be combined, and means for combining output signals taken from the outputs of the first mentioned band pass filter means of each for demodUlation.
Claim 6
Dependent Claim
58 words
A frequency diversity combining arrangement as claimed in claim 4 and including AGC amplifiers, one in each input path from a diversity channel to the two palanced mixers of a signal handling arrangement which AGC amplifiers are controlled by an AGC detector connected to derive its input from the common output of all of said signal handling arrangements.
Claim 7
Dependent Claim
224 words
A signal handling arrangement suitable for use in frequency diversity predetection combining arrangement, comprising in combination: a pair of balanced mixers each having a pair of inputs and an output; means for applying an input signal in parallel to both mixers; phase locked loop means connecting the output of one mixer to the second input of the other mixer for tracking over a range corresponding to the difference in input frequency which may be expected in a frequency diversity combining system while maintaining passage of signals in one of the sidebands of the output from the other mixer; bandpass filter means connected to the output of said other mixer for passing said signals in said one of the sidebands of said other mixer; output means connected to said bandpass filter means for providing the second input to said one mixer and comprising a linearly variable attenuator; a further balanced mixer having a pair of inputs and an output; a 90* phase shifter connected to the output of said one mixer and providing one input to said further mixer, the further mixer having its second input connected to the output of said phase locked loop means; and means connecting the output of said further mixer to said attenuator for maintaining an output from said attenuator which is proportional to the square of the input signal.
Claim 8
Dependent Claim
224 words
A signal handling arrangement suitable for use in frequency diversity predetection combining arrangement, comprising in combination: a pair of balanced mixers each having a pair of inputs and an output; means for applying an input signal in parallel to both mixers; phase locked loop means connecting the output of one mixer to the second input of the other mixer for tracking over a range corresponding to the difference in input frequency which may be expected in a frequency diversity combining system while maintaining passage of signals in one of the sidebands of the output from the other mixer; bandpass filter means connected to the output of said other mixer for passing said signals in said one of the sidebands of said other mixer; output means connected to said bandpass filter means for providing the second input to said one mixer and comprising a linearly variable attenuator; a further balanced mixer having a pair of inputs and an output; a 90* phase shifter connected to the output of said one mixer and providing one input to said further mixer, the further mixer having its second input connected to the output of said phase locked loop means; and means connecting the output of said further mixer to said attenuator for maintaining an output from said attenuator which is proportional to the square of the input signal.
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) | 1978-01-06 | 1978-07-08 | 1979-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-06 | 1982-07-08 | 1983-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-06 | 1986-07-08 | 1987-01-07 | $7700.00 | Window Closed / Lapsed |