US5093930A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Directly mixing synchronous am receiver
Assignee: NXP BV
•
Filing: 1989-10-25
•
Granted: 1992-03-03
•
Expires: 2009-10-25
Abstract
Abstract A directly mixing synchronous AM receiver includes a synchronous demodulator coupled to an antenna input for synchronously demodulating an RF-AM reception carrier and a phase-locked loop (PLL) incorporating a phase detection arrangement, a loop filter, a controllable oscillator which is coupled to the synchronous demodulator via an in-phase output and to the phase detection arrangement via a quadrature output. In order to increase the dynamic range of the receiver, it is provided with a controllable amplification arrangement in the phase-locked loop to which a gain control signal is applied from a control signal generating circuit for reducing field strength-dependent amplitude variations of the signal in the phase-locked loop. The control signal generating circuit includes mixing device having in succession, mutually coupled first and second mixer stages, to which first mixer stage a first mixing subcarrier as applied from a signal generator, the antenna input being connected to an input of one of the first and second mixer stages and the in-phase output of the controllable oscillator being connected to an input of the other mixer stage, the mixing device being coupled via an output of the second mixer stage to a selection circuit for selecting at least the frequency of the first mixing subcarrier, followed by an amplitude detection arrangement for detecting the amplitude of the first mixing subcarrier, the amplitude detection arrangement being coupled to a control input of the controllable amplification arrangement.
Inventors
- 👤 Wolfdietrich G. Kasperkovitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:11
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/06; H04B1/16; H04B1/30; H03; H03D; H03D1/00; H03D1/22; H03D1/2245; H03D1/2254; H03D2200/00; H03D2200/0001; H03D2200/0025
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
253 words
A directly mixing synchronous AM receiver having a synchronous demodulator coupled to an antenna input for synchronously demodulating an RF-AM reception carrier, and a phase-locked loop including a phase detection arrangement, a loop filter, and a controllable oscillator, said controllable oscillator being coupled to the synchronous demodulator via an in-phase output and to the phase detection arrangement via a quadrature output, characterized in that said receiver further comprises: a controllable amplification arrangement included in said phase-locked loop, said controllable amplification arrangement having a control input for receiving a gain control signal; and a control signal generating circuit for reducing field strength-dependent amplitude variations of the signal in the phase-locked loop, said control signal generating circuit generating said gain control signal for said controllable amplification arrangement, and comprising: a signal generator for generating a mixing subcarrier; a mixing device having, in succession, mutually coupled first and second mixer stages, said first mixer stage receiving said mixing subcarrier, the antenna input being connected to an input of one of the first and second mixer stages and the in-phase output of the controllable oscillator being connected to an input of the other of said first and second mixer stages; selection means coupled to an output of said second mixer stage for selecting at least the frequency of the mixing subcarrier; and an amplitude detection arrangement coupled to an output of said selection means for detecting the amplitude of the mixing subcarrier, said amplitude detection arrangement being coupled to the control input of said controllable amplification arrangement.
Claim 2
Dependent Claim
253 words
A directly mixing synchronous AM receiver having a synchronous demodulator coupled to an antenna input for synchronously demodulating an RF-AM reception carrier, and a phase-locked loop including a phase detection arrangement, a loop filter, and a controllable oscillator, said controllable oscillator being coupled to the synchronous demodulator via an in-phase output and to the phase detection arrangement via a quadrature output, characterized in that said receiver further comprises: a controllable amplification arrangement included in said phase-locked loop, said controllable amplification arrangement having a control input for receiving a gain control signal; and a control signal generating circuit for reducing field strength-dependent amplitude variations of the signal in the phase-locked loop, said control signal generating circuit generating said gain control signal for said controllable amplification arrangement, and comprising: a signal generator for generating a mixing subcarrier; a mixing device having, in succession, mutually coupled first and second mixer stages, said first mixer stage receiving said mixing subcarrier, the antenna input being connected to an input of one of the first and second mixer stages and the in-phase output of the controllable oscillator being connected to an input of the other of said first and second mixer stages; selection means coupled to an output of said second mixer stage for selecting at least the frequency of the mixing subcarrier; and an amplitude detection arrangement coupled to an output of said selection means for detecting the amplitude of the mixing subcarrier, said amplitude detection arrangement being coupled to the control input of said controllable amplification arrangement.
Claim 3
Dependent Claim
118 words
A directly mixing synchronous AM receiver as claimed in claim 1, characterized in that the phase detection arrangement comprises means for modulating the phase information on a further mixing subcarrier generated by said signal generator, in that the phase-locked loop incorporates, between the phase detection arrangement and the loop filter, successively, and adder circuit for adding the output signals of the phase detection arrangement and the second mixer stage, said selection means, the controllable amplification arrangement, and a third mixer stage for demodulating the further mixing subcarrier, said selection means also selecting the frequency of the further mixing subcarrier, and an output of the controllable amplification arrangement being coupled to an input of the said amplitude detection arrangement.
Claim 4
Dependent Claim
118 words
A directly mixing synchronous AM receiver as claimed in claim 2, characterized in that the phase detection arrangement comprises, in succession, mutually coupled fourth and fifth mixer stages, the further mixing subcarrier being applied to said fourth mixer stage, the antenna input being connected to one of the fourth and fifth mixer stages and the quadrature output of the controllable oscillator being connected to the other of the fourth and fifth mixer stages, the further mixing subcarrier being applied via a delay circuit to said third mixer stage, said delay circuit having a delay period which substantially corresponds to the delay of the signal in the phase-locked loop between the phase detection arrangement and the third mixer stage.
Claim 5
Dependent Claim
27 words
A directly mixing synchronous AM receiver as claimed in claim 2 or 3, characterized in that the mixing subcarriers mutually correspond in frequency and differ in phase.
Claim 6
Dependent Claim
80 words
A directly mixing synchronous AM receiver as claimed in claim 4, characterized in that the amplitude detection arrangement has a sixth mixer stage to which the mixing subcarrier is applied via a delay circuit having a delay period which substantially corresponds to the delay of the signal in the phase-locked loop between the phase detection arrangement and the sixth mixer stage, said sixth mixer stage being coupled to the control input of the controllable amplification arrangement via a low-pass filter.
Claim 7
Dependent Claim
33 words
A directly mixing synchronous AM receiver as claimed in claim 5, characterized in that the selection means comprises a low-pass filter, and the controllable amplification arrangement is provided with a DC negative feedback.
Claim 8
Dependent Claim
33 words
A directly mixing synchronous AM receiver as claimed in claim 4, characterized in that the selection means comprises a low-pass filter, and the controllable amplification arrangement is provided with a DC negative feedback.
Claim 9
Dependent Claim
82 words
A directly mixing synchronous AM receiver as claimed in claim 2 or 3, characterized in that the amplitude detection arrangement has a sixth mixer stage to which the mixing subcarrier is applied via a delay circuit having a delay period which substantially corresponds to the delay of the signal in the phase-locked loop between the phase detection arrangement and the sixth mixer stage, said sixth mixer stage being coupled to the control input of the controllable amplification arrangement via a low-pass filter.
Claim 10
Dependent Claim
33 words
A directly mixing synchronous AM receiver as claimed in claim 8, characterized in that the selection means comprises a low-pass filter, and the controllable amplification arrangement is provided with a DC negative feedback.
Claim 11
Dependent Claim
35 words
A directly mixing synchronous AM receiver as claimed in claims 2 or 3, characterized in that the selection means comprise a low-pass filter, and the controllable amplification arrangement is provided with a DC negative feedback.
References Cited (Backward Citations)
US3209271A
Cited
US4355417A
Cited
US4473801A
Cited
US4631499A
Cited
US4864840A
Cited
US4816771A
Cited
US4953182A
Cited
US4972163A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-03-03 | 1995-09-02 | 1996-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-03 | 1999-09-02 | 2000-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-03 | 2003-09-02 | 2004-03-03 | $7700.00 | Window Closed / Lapsed |