Detector for indicating reception disturbances during ultrashort wave broadcast reception

Claim 2

A detector for indicating reception disturbances during ultrashort wave broadcast reception in a receiver having a frequency demodulator with a given passband and responsive to an IF signal in the receiver, particularly in power vehicles, comprising a detector for deriving a first output signal indicating disturbance-related frequency deviation in a high or intermediate frequency carrier; an amplitude modulation detector for deriving a second output signal indicating disturbance-related amplitude modulation in the high frequency or intermediate frequency carrier; and an evaluating circuit having first and second inputs that receive said first and second output signals of said detectors, respectively, said evaluating circuit including means responsive to said first and second output signals for deriving an output signal that depends both on the disturbance-related amplitude modulation and the disturbance-related frequency deviation as respectively indicated by said detectors.

Claim 3

A detector as defined in claim 1, wherein said evaluating circuit signal deriving means comprises a logic circuit arranged so that the output signal of said evaluating circuit has a binary character and that the occurrence of a reception disturbance is indicated only when both the disturbance-related frequency deviation and the disturbance-related amplitude modulation exceed respective suitably adjusted threshold values.

Claim 4

A detector as defined in claim 1, wherein said amplitude modulation detector for indicating the disturbance-related amplitude modulation is formed as an envelope curve demodulator.

Claim 5

A detector as defined in claim 3, wherein said amplitude modulation detector has a frequency bandwidth which is at least equal to a channel bandwidth of an ultrashort wave channel.

Claim 6

A detector as defined in claim 2, wherein said evaluating circuit signal deriving means also includes a level discriminator supplied with the output signal of said detector for indicating the disturbance-related frequency deviation, and a further, unipolar, level discriminator which is supplied with the output signal of said amplitude modulation detector, said level discriminators being arranged so that their output signals are supplied to said logic circuit of said evaluating circuit at whose output the presence of the reception disturbance is indicated by a binary signal.

Claim 7

A detector as defined in claim 5, wherein said first mentioned level discriminator is a unipolarly operating level discriminator.

Claim 8

A detector as defined in claim 5, wherein said first-mentioned level discriminator is a bipolarly operating level discriminator.

Claim 9

A detector as defined in claim 5, wherein said disturbance-related frequency deviation detector includes a wide-band FM demodulator connected in cascade with a circuit for increasing the steepness of pulse flanks, applied to said first-mentioned level discriminator.

Claim 10

A detector as defined in claim 5, wherein said amplitude modulation detector includes an amplitude modulation demodulator; and further comprising a circuit for increasing the steepness of pulse flanks arranged after said amplitude modulation demodulator and supplying the processed signal of said amplitude modulation detector to said second mentioned level discriminator.

Claim 11

A detector as defined in claim 5, and further comprising circuits for increasing the steepness of pulse flanks, arranged respectively prior to the input of said evaluating circuit receiving the output signals for indicating the disturbance-related amplitude modulation and at the input receiving the output signal for indicating the disturbance-related frequency deviation, and wherein output signals of said circuits for increasing the steepness of pulse flanks are supplied to said level discriminators, respectively.

Claim 12

A detector as defined in claim 10, wherein each of said circuits for increasing the steepness of pulse flanks includes a differentiating member composed of a series capacitance C and a parallel resistance R and a time constant RC adjusted so that for the output signal for indicating the disturbance-related frequency deviation it provides a reliable separation between the disturbance-related frequency deviation and longer-duration useful deviation pulses, and for the output signal for indicating the disturbance-related amplitude modulation it provides a reliable separation between local field intensity fluctuations and the disturbance-related amplitude modulation.

Claim 13

A detector as defined in claim 8, wherein said circuit for increasing the steepness of pulse flanks is composed of differentiating members connected with one another in a chain.

Claim 14

A detector as defined in claim 2, wherein said evaluating circuit signal deriving means includes two unipolarly operating level discriminators and the logic circuit, one of said level discriminators having only one level threshold which is adjusted for indicating the exceeding of a predetermined positive or negative frequency deviation, said level discriminators being arranged so that their output signals are supplied to said logic circuit and at an output of said logic circuit the presence of the reception disturbance is indicated by a binary signal.

Claim 15

A detector as defined in claim 13, wherein said evaluating circuit is provided at one input with a circuit having the character of a full wave rectifier and arranged after said detector for indicating the disturbance-related frequency deviation so that the processed output signal of said detector for indicating the disturbance-related frequency deviation is supplied to said circuit, said circuit having the character of a full wave rectifier being formed to convert input impulses with different polarities into output impulses with identical polarity and to supply the thus-processed signal to said one unipolar level discriminator with said subsequently arranged logic circuit.

Claim 16

A detector as defined in claim 8, wherein said circuit for increasing the steepness of pulse flanks is composed relative to the ratio between output and input signals thereof of an exponential function with an even-numbered exponent greater than 1.

Claim 17

A detector as defined in claim 8, wherein said circuit for increasing the steepness of pulse flanks is composed of a sum of exponential functions with identical signs, and with even exponents greater than the 1.

Claim 18

A detector as defined in claim 8, wherein said circuit for increasing the steepness of pulse flanks relative to the ratio between the output andinput signals thereof is composed of a function with the character of a hyperbolic cosine function.

Claim 19

A detector as defined in claim 2, wherein said logic circuit has the character of an AND-gate.

Claim 20

A detector as defined in claim 1, wherein said evaluating circuit includes a circuit for analog combination of the output signal of said detector for indicating the disturbance-related frequency deviation and the output signal of said amplitude modulation detector, and a level discriminator in cascade with a logic circuit so that at an output of said evaluating circuit the presence of the reception disturbance is indicated by a binary signal.

Claim 21

A detector as defined in claim 19, wherein said level discriminator has a level threshold which is adjusted for indicating exceeding of a predetermined frequency deviation and an output signal of said level discriminator is supplied to said logic circuit at whose output the presence of the reception disturbance is indicated by a binary signal.

Claim 22

A detector as defined in claim 19, wherein said level discriminator has level thresholds adjusted for indicating exceeding of a predetermined frequency disturbance deviation and an output signal of said level discriminator is supplied to said logic circuit at whose output the presence of the reception disturbance is indicated by a binary signal.

Claim 23

A detector as defined in claim 21, wherein said level discriminator is a bipolarly operating level discriminator.

Claim 24

A detector as defined in claim 20, wherein said level discriminator is a unipolarly operating level discriminator.

Claim 25

A detector as defined in claim 22, wherein said evaluating circuit has its input coupled to a circuit for increasing the steepness of pulse flanks and a processed signal is supplied y said circuit to said level discriminator.

Claim 26

A detector as defined in claim 24, wherein said circuit for increasing the steepness of pulse flanks is formed as a differentiating member including a series capacitance C and a parallel resistance R providing a time constant RC adjusted so as to provide a reliable separation of the shorter-duration disturbance pulses from the longer-duration useful deviation pulses.

Claim 27

A detector as defined in claim 24, wherein said circuit for increasing the steepness of the pulse flanks includes a plurality of differentiating members connected with one another in a chain.

Claim 28

A detector as defined in claim 19, wherein said level discriminator is a unipolarly operating level discriminator and has only one level threshold adjusted for indicating exceeding of a predetermined positive or negative frequency deviation and an output signal of said level discriminator is supplied to said logic circuit at whose output the presence of the reception disturbance is indicated by a binary signal.

Claim 29

A detector as defined in claim 19, wherein said evaluating circuit has its input coupled to a circuit of the character of a full-wave rectifier which converts input impulses with different polarity into output impulses with identical polarity and the thus-processed signal is supplied to said level discriminator.

Claim 30

A detector as defined in claim 24, wherein said circuit for increasing the steepness of pulse flanks relative to the ratio between output and input signals thereof is composed of an exponential function with an even-numbered exponent greater than 1.

Claim 31

A detector as defined in claim 24, wherein said circuit for increasing the steepness of pulse flanks is composed of a sum of exponential functions with identical signs and with even exponential greater than 1.

Claim 32

A detector as defined in claim 24, wherein said circuit for increasing the steepness of pulse flanks relative to the ratio between output and input signals thereof is composed of a function with the character of a hyberbolic cosine function.

Claim 33

A detector for indicating reception disturbances during ultrashort wave broadcast reception, particularly in power vehicles, comprising a detector for indicating disturbance-related frequency deviation in a high or intermediate frequency carrier; an amplitude modulation detector for indicating disturbance-related amplitude modulation in the high frequency or intermediate frequency carrier; an evaluating circuit having two inputs and arranged so that output signals of said detectors are supplied respectively to said inputs of said evaluating circuit and an output signal of said evaluating circuit depends on the disturbance-related amplitude modulation and the disturbance-related frequency deviation, said evaluating circuit including a logic circuit formed so that the output signal of said evaluating circuit has a binary character and that the occurrence of a reception disturbance is indicated only when both the disturbance-related frequency deviation and the disturbance-related amplitude modulation exceed respective suitably adjusted threshold values, a level discriminator supplied with the output signal of said detector for indicating the disturbance-related frequency deviation, and a further, unipolar, level discriminator which is supplied with the output signal of said amplitude modulation detector, said level discriminators being arranged so that their output signals are supplied to said logic circuit of said evaluating circuit at whose output the presence of the reception disturbance is indicated by a binary signal, at least one of said level discriminators having an adjustable level threshold; means for averaging the frequency deviation over time; and means for dynamically adjusting said level threshold in dependence on the time-averaged frequency deviation.

Claim 34

A detector for indicating reception disturbances during ultrashort wave broadcast reception, particularly in power vehicles, comprising a detector for indicating disturbance-related frequency deviation in a high or intermediate frequency carrier; an amplitude modulation detector for indicating disturbance-related amplitude modulation in the high frequency or intermediate frequency carrier; an evaluating circuit having two inputs and arranged so that output signals of said detectors are supplied respectively to said inputs of said evaluating circuit and an output signal of said evaluating circuit depends on the disturbance-related amplitude modulation and the disturbance-related frequency deviation, said evaluating circuit including a logic circuit formed so that the output signal of said evaluating circuit has a binary character and that the occurrence of a reception disturbance is indicated only when both the disturbance-related frequency deviation and the disturbance-related amplitude modulation exceed respective suitably adjusted threshold values, a level discriminator supplied with the output signal of said detector for indicating the disturbance-related frequency deviation, and a further, unipolar, level discriminator which is supplied with the output signal of said amplitude modulation detector, said level discriminators being arranged so that their output signals are supplied to said logic circuit of said evaluating circuit at whose output the presence of the reception disturbance is indicated by a binary signal, at least one of said level discriminators having an adjustable level threshold; means for averaging the frequency deviation over time; and means for dynamically adjusting said level threshold in dependence on the time-averaged frequency deviation.

Claim 35

A detector as defined in claim 32, wherein each of said level discriminators has an adjustable level threshold; and wherein said adjusting means is operative for dynamically adjusting each of said level thresholds in dependence on the time-averaged frequency deviation.

Claim 36

A detector as defined in claim 32, wherein said adjusting means is operative for so adjusting said at least one level discriminator that the level threshold thereof increases with an increase of the time-averaged frequency deviation.

Claim 37

A detector as defined in claim 5; and further comprising a circuit for detecting the signal/noise ratio in a base-band signal, at least one of said level discriminators having an adjustable level threshold; and further comprising means for averaging the frequency deviation over time; and means for adjusting said level threshold in dependence on the signal/noise ratio.

Claim 38

A detector as defined in claim 35, wherein each of said level discriminators has an adjustable level threshold; and wherein said adjusting means is operative for adjusting each of said level thresholds in dependence on the signal/noise ratio.

Claim 39

A detector as defined in claim 35, wherein said adjusting means is operative for so adjusting said at least one level discriminator that the level threshold thereof is dynamically increased with an increase of the signal/noise ratio.

Claim 40

A detector for indicating reception disturbances during ultrashort wave broadcast reception, particularly in power vehicles, comprising a detector for indicating disturbance-related frequency deviation in a high or intermediate frequency carrier; an amplitude modulation detector for indicating disturbance-related amplitude modulation in the high frequency or intermediate frequency carrier; an evaluating circuit having two inputs and arranged so that output signals of said detectors are supplied respectively to said inputs of said evaluating circuit and an output signal of said evaluating circuit depends on the disturbance-related amplitude modulation and the disturbance-related frequency deviation, said evaluating circuit including a logic circuit formed so that the output signal of said evaluating circuit has a binary character and that the occurrence of a reception disturbance is indicated only when both the disturbance-related frequency deviation and the disturbance-related amplitude modulation exceed respective suitably adjusted threshold values, a level discriminator supplied with the output signal of said detector for indicating the disturbance-related frequency deviation, and a further, unipolar, level discriminator which is supplied with the output signal of said amplitude modulation detector, said level discriminators being arranged so that their output signals are supplied to said logic circuit of said evaluating circuit at whose output the presence of the reception disturbance is indicated by a binary signal, at least one of said level discriminators having an adjustable level threshold; means for averaging the carrier amplitude over time; and means for adjusting said level threshold in dependence on the time-averaged carrier amplitude.

Claim 41

A detector for indicating reception disturbances during ultrashort wave broadcast reception, particularly in power vehicles, comprising a detector for indicating disturbance-related frequency deviation in a high or intermediate frequency carrier; an amplitude modulation detector for indicating disturbance-related amplitude modulation in the high frequency or intermediate frequency carrier; an evaluating circuit having two inputs and arranged so that output signals of said detectors are supplied respectively to said inputs of said evaluating circuit and an output signal of said evaluating circuit depends on the disturbance-related amplitude modulation and the disturbance-related frequency deviation, said evaluating circuit including a logic circuit formed so that the output signal of said evaluating circuit has a binary character and that the occurrence of a reception disturbance is indicated only when both the disturbance-related frequency deviation and the disturbance-related amplitude modulation exceed respective suitably adjusted threshold values, a level discriminator supplied with the output signal of said detector for indicating the disturbance-related frequency deviation, and a further, unipolar, level discriminator which is supplied with the output signal of said amplitude modulation detector, said level discriminators being arranged so that their output signals are supplied to said logic circuit of said evaluating circuit at whose output the presence of the reception disturbance is indicated by a binary signal, at least one of said level discriminators having an adjustable level threshold; means for averaging the carrier amplitude over time; and means for adjusting said level threshold in dependence on the time-averaged carrier amplitude.

Claim 42

A detector as defined in claim 38, wherein each of said level discriminators has an adjustable level threshold; and wherein said adjusting means is operative for dynamically adjusting each of said level thresholds in dependence on the time-averaged carrier amplitude.

Claim 43

A detector as defined in claim 38, wherein said adjusting means is operative for so adjusting said at least one level discriminator that the level threshold thereof is adjusted exclusively in dependence on the time-averaged carrier amplitude.

Claim 44

A detector as defined in claim 38, wherein said adjusting means is operative for so adjusting said at least one level discriminator that the level threshold thereof is adjusted additionally in dependence on the time-averaged carrier amplitude.

Claim 45

A detector as defined in claim 38, wherein said adjusting means is operative for so adjusting said at least one level discriminator that the level threshold thereof is increased with decreasing carrier amplitude.

Claim 46

A detector as defined in claim 5; and further comprising a circuit for detecting the peak value of the useful frequency deviation, at least one of said level discriminators having an adjustable threshold; and further comprising means for averaging the frequency deviation over time; and means for adjusting said threshold in dependence on the peak values of the useful frequency deviation.

Claim 47

A detector as defined in claim 43, wherein each of said level discriminators has an adjustable threshold; and wherein said adjusting means is operative for adjusting each of said thresholds in dependence on the peak values of the useful frequency deviation.

Claim 48

A detector as defined in claim 43, wherein said adjusting means is operative for adjusting the threshold of said at least one level discriminator exclusively in dependence on the peak values of the useful frequency deviation.

Claim 49

A detector as defined in claim 43, wherein said adjusting means is operative for adjusting the threshold of said at least one level discriminator additionally in dependence on the peak values of the useful frequency deviation.

Claim 50

A detector as defined in claim 43, wherein said at least one level discriminator is formed so that with increasing peak values of the frequency effective deviation the level threshold is increased.

Claim 51

In an FM receive having a signal transmission channel with a given frequency bandwidth and an FM demodulator, a detector circuit for indicating reception disturbances in a received signal due to multipath signal reception comprising: a first FM detector responsive to a carrier frequency signal in said receiver transmission channel for deriving a first output signal indicative of a disturbance-related frequency deviation in said carrier signal, a second AM detector responsive to said carrier frequency signal for deriving a second output signal indicative of a disturbance-related amplitude modulation in said carrier signal, and an evaluating circuit having input means that receive said first and second output signals and means responsive to said first and second output signals for deriving a further output signal dependent thereon to provide a rapid indication of a reception disturbance which indication appears substantially instantaneously with the occurrence of the reception disturbance.

Claim 52

In an FM receive having a signal transmission channel with a given frequency bandwidth and an FM demodulator, a detector circuit for indicating reception disturbances in a received signal due to multipath signal reception comprising: a first FM detector responsive to a carrier frequency signal in said receiver transmission channel for deriving a first output signal indicative of a disturbance-related frequency deviation in said carrier signal, a second AM detector responsive to said carrier frequency signal for deriving a second output signal indicative of a disturbance-related amplitude modulation in said carrier signal, and an evaluating circuit having input means that receive said first and second output signals and means responsive to said first and second output signals for deriving a further output signal dependent thereon to provide a rapid indication of a reception disturbance which indication appears substantially instantaneously with the occurrence of the reception disturbance.

Claim 53

A detector circuit as claimed in claim 48 wherein said evaluating circuit comprises a logic circuit for supplying said further output signal and level discriminator means responsive to at least one electrical parameter of the receiver for effectively adjusting the response level of the logic circuit dependent upon said electrical parameter.

Claim 54

A detector circuit as claimed in claim 49 wherein said level discriminator means is responsive to at least one of said first and second output signals.

Claim 55

A detector circuit as claimed in claim 50 further comprising pulse enhancement circuit means connected in cascade with at least one of said first and second detectors and said level discriminator means.