Abstract: A method and an apparatus for squelch gating a receiving signal depending on the level of phase noise in said receiving signal determines sampled amplitudes and sampled phases of said receiving signal, determines sampled phase noise by differentiating subsequent sampled phases, determines a squelch signal by rectifying and averaging said sampled phase noise, determines a start point of gating after a rising of said squelch signal above a higher threshold delayed by a first delay time, determines a end point of gating after a dropping of said squelch signal below a lower threshold delayed by a second delay time and gates said sampled amplitudes from said start point of gating until said end point of gating.

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.

Abstract: A measurement apparatus (1) for measuring peak pulses of a radio frequency input signal (RFinput) comprises mixing means for mixing the radio frequency input signal (RFinput) with a local oscillator signal (LO) in order to convert the radio frequency input signal (RFinput) directly to zero centre frequency thereby suppressing frequency components in a range close to zero frequency. Control means (20) control the frequency (fLO) of the local oscillator signal (LO) in a manner that a first measurement is performed in a first frequency range and that a second measurement is performed in a second frequency range shifted from the first frequency range.

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.

Abstract: A method and an apparatus for squelch gating a receiving signal depending on the level of phase noise in said receiving signal determines sampled amplitudes and sampled phases of said receiving signal, determines sampled phase noise by differentiating subsequent sampled phases, determines a squelch signal by rectifying and averaging said sampled phase noise, determines a start point of gating after a rising of said squelch signal above a higher threshold delayed by a first delay time, determines a end point of gating after a dropping of said squelch signal below a lower threshold delayed by a second delay time and gates said sampled amplitudes from said start point of gating until said end point of gating.

Abstract: An apparatus (1) for analyzing a spectrum of an input signal (x(t)) having at least one line with a center frequency (@s) comprises a mixer (2) for zero-mixing the input signal (x(t)) to produce a base band signal (z(t)) by sweeping a local oscillator frequency (@s) generated by a local oscillator (3) and a resolution filter (4) for filtering the base band signal (z(t)) to produce a filtered base band signal (y(t)). Detector means (7) detects the time of occurrence (ti), the duration (?Ti) and the maximum value (y?i) of several halfwaves of the filtered base band signal (y(t)). Envelope reconstruction means (6) reconstructs the envelope (E(@)) of the spectrum of the input signal (x(t)) by using an estimated amplitude at an estimated center frequency of each line of the input signal (x(t)).

Abstract: A quasi-peak detector (1) for detecting the weighted peak value (quasi peak) of the envelope of a signal (Sin) comprises a digital charging and discharging filter (11) which simulates the process of charging and discharging a capacitor (C1). The digital charging and discharging filter (11) simulates charging through an inductor (L1).

Abstract: A measurement apparatus (1) for measuring peak pulses of a radio frequency input signal (RFinput) comprises mixing means for mixing the radio frequency input signal (RFinput) with a local oscillator signal (LO) in order to convert the radio frequency input signal (RFinput) directly to zero centre frequency thereby suppressing frequency components in a range close to zero frequency. Control means (20) control the frequency (fLO) of the local oscillator signal (LO) in a manner that a first measurement is performed in a first frequency range and that a second measurement is performed in a second frequency range shifted from the first frequency range.

Abstract: An apparatus (1) for analyzing a spectrum of an input signal (x(t)) having at least one line with a center frequency (@s) comprises a mixer (2) for zero-mixing the input signal (x(t)) to produce a base band signal (z(t)) by sweeping a local oscillator frequency (@s) generated by a local oscillator (3) and a resolution filter (4) for filtering the base band signal (z(t)) to produce a filtered base band signal (y(t)). Detector means (7) detects the time of occurrence (ti), the duration (&Dgr;Ti) and the maximum value (y′i) of several halfwaves of the filtered base band signal (y(t)). Envelope reconstruction means (6) reconstructs the envelope (E(@)) of the spectrum of the input signal (x(t)) by using an estimated amplitude at an estimated center frequency of each line of the input signal (x(t)).