Method and apparatus for leveling an increasing or decreasing slope of an AM modulated receiving signal
AssigneeRohde & Schwarz GmbH & Co. KG
InventorsReiner Hausdorf, Leo Brueckner
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Abstract
A method and an apparatus for leveling an increasing or decreasing slope of an AM modulated receiving signal attenuate the AM modulated receiving signal with an attenuation curve with a stepwise slope corresponding to the increasing or decreasing slope of said AM modulated receiving signal, filters the attenuated AM modulated receiving signal within AM-demodulation with a lowpass infinite-impulse-response filter of at least second order and increases the level of each delay-unit's output signal of the infinite-impulse-response filter each time a step in the attenuated AM modulated receiving signal arrives at the input of said infinite-impulse-response filter.
Claims9
Method for leveling an increasing or decreasing slope of an AM modulated receiving signal comprising the following steps:
- attenuating the AM modulated receiving signal with an attenuation curve with a stepwise slope corresponding to the increasing or decreasing slope of the AM modulated receiving signal,
- filtering the attenuated AM modulated receiving signal with a lowpass filter having at least one delay unit within AM-demodulation, and
- increasing the level of the output signal of each delay unit of the lowpass filter each time a step in said attenuated AM modulated receiving signal arrives at the input of the lowpass filter (14).
Apparatus for leveling an increasing or decreasing slope of an AM modulated receiving signal comprising:
- an attenuator for attenuating said receiving signal corresponding to an attenuation curve,
- an automatic gain control measuring said receiving signal control and generating said attenuation curve with a stepwise slope corresponding to said increasing or decreasing slope of said receiving signal,
- a lowpass filter within an AM-demodulator filtering said attenuated receiving signal, and
- a delay buffer for delaying a control signal signaling each step in said attenuated receiving signal for the delay time of said attenuated receiving signal from said attenuator to said lowpass filter.
Dependencies are inferred from the claim text.