GB1338569A - Receivers for frequency modulated oscillations - Google Patents
Receivers for frequency modulated oscillationsInfo
- Publication number
- GB1338569A GB1338569A GB5769070A GB5769070A GB1338569A GB 1338569 A GB1338569 A GB 1338569A GB 5769070 A GB5769070 A GB 5769070A GB 5769070 A GB5769070 A GB 5769070A GB 1338569 A GB1338569 A GB 1338569A
- Authority
- GB
- United Kingdom
- Prior art keywords
- discriminator
- pulses
- threshold circuit
- signals
- dec
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 230000010355 oscillation Effects 0.000 title 1
- 239000003990 capacitor Substances 0.000 abstract 1
- 230000004069 differentiation Effects 0.000 abstract 1
- 230000002452 interceptive effect Effects 0.000 abstract 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03G—CONTROL OF AMPLIFICATION
- H03G3/00—Gain control in amplifiers or frequency changers
- H03G3/20—Automatic control
- H03G3/30—Automatic control in amplifiers having semiconductor devices
- H03G3/34—Muting amplifier when no signal is present or when only weak signals are present, or caused by the presence of noise signals, e.g. squelch systems
- H03G3/341—Muting when no signals or only weak signals are present
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
- H03D3/00—Demodulation of angle-, frequency- or phase- modulated oscillations
- H03D3/02—Demodulation of angle-, frequency- or phase- modulated oscillations by detecting phase difference between two signals obtained from input signal
- H03D3/04—Demodulation of angle-, frequency- or phase- modulated oscillations by detecting phase difference between two signals obtained from input signal by counting or integrating cycles of oscillations
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03G—CONTROL OF AMPLIFICATION
- H03G11/00—Limiting amplitude; Limiting rate of change of amplitude ; Clipping in general
- H03G11/02—Limiting amplitude; Limiting rate of change of amplitude ; Clipping in general by means of diodes
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03G—CONTROL OF AMPLIFICATION
- H03G3/00—Gain control in amplifiers or frequency changers
- H03G3/20—Automatic control
- H03G3/30—Automatic control in amplifiers having semiconductor devices
- H03G3/34—Muting amplifier when no signal is present or when only weak signals are present, or caused by the presence of noise signals, e.g. squelch systems
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
- Noise Elimination (AREA)
Abstract
1338569 Frequency demodulators LICENTIA PATENT-VERWALTUNGS-GmbH 4 Dec 1970 [15 Dec 1969] 57690/70 Heading H3A A frequency demodulator comprises a counting discriminator, such as 1, in which the incoming F.M. signals are initially limited to obtain rectangular pulses from which pulses of equal width are generated by differentiation, the latter pulses being used to generate a waveform (Fig. 3, not shown), e.g. by the charge and discharge of a capacitor 5, which contains the modulation information, an amplitude threshold circuit 7-9 for rejecting components of the waveform of amplitude below a given value which represents interference signals and an arrangement 10, 11 for extracting the modulation information. The demodulated output may be amplified at 13-16. In the alternative embodiment of Fig. 5 (not shown), the low-pass filter 10, 11 is interposed between the discriminator 1 and the threshold circuit. In a further embodiment (Fig. 6, not shown) the amplifying transistor 13 has its bias adjusted to provide the required threshold. The combination of the discriminator 1 and the threshold circuit 7-9 provides better selectivity (Fig. 4, not shown) against interfering signals than that provided by the discriminator 1 alone.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19691962755 DE1962755C3 (en) | 1969-12-15 | 1969-12-15 | Circuit to increase the selection of an FM receiver with number discriminator |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1338569A true GB1338569A (en) | 1973-11-28 |
Family
ID=5753890
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB5769070A Expired GB1338569A (en) | 1969-12-15 | 1970-12-04 | Receivers for frequency modulated oscillations |
Country Status (2)
Country | Link |
---|---|
DE (1) | DE1962755C3 (en) |
GB (1) | GB1338569A (en) |
-
1969
- 1969-12-15 DE DE19691962755 patent/DE1962755C3/en not_active Expired
-
1970
- 1970-12-04 GB GB5769070A patent/GB1338569A/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
DE1962755B2 (en) | 1973-04-19 |
DE1962755A1 (en) | 1971-06-16 |
DE1962755C3 (en) | 1973-11-08 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
GB979865A (en) | Improvements in or relating to pulse-counting detector circuits | |
US4350957A (en) | Pulse counter-type FM detector | |
GB1514556A (en) | Signal processor for reducing interference between frequency-modulated signals | |
GB1486808A (en) | Radio receivers | |
GB1338569A (en) | Receivers for frequency modulated oscillations | |
GB1486517A (en) | Phase detector | |
SE317106B (en) | ||
GB1262875A (en) | Angle modulation system | |
US2517618A (en) | Detector for time modulated pulses | |
GB984588A (en) | Squelch circuit | |
US2959673A (en) | Radio receiver squelch control | |
US3056087A (en) | Noise blanking circuit | |
JPS57211811A (en) | Demodulating circuit for modulated signal | |
GB1359903A (en) | Demodulator circuit | |
US2971159A (en) | Amplitude modulation eliminator | |
US3345576A (en) | Simplified pulse counter fm demodulator | |
US3275939A (en) | Noise modulation control system | |
US2839750A (en) | A. g. c. degenerative control means | |
GB1332522A (en) | Pulse density demodulator | |
GB1448684A (en) | If amplifiers | |
US2276154A (en) | Multichannel signaling system | |
US3222606A (en) | Detector for am, cw, or ssb signals providing inherent agc signal | |
GB792350A (en) | Improvements in or relating to single-sideband radio receivers | |
SU451167A1 (en) | Device for processing frequency-modulated oscillations | |
SU466607A1 (en) | Automatic gain control device |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed | ||
PLNP | Patent lapsed through nonpayment of renewal fees |