Abstract: Generally, in accordance with the various illustrative embodiments of the invention, a signal analyzer can incorporate a quasi-peak detection circuit that includes a detector diode. The detector diode is reverse-biased by using a direct-current (DC) voltage source. In some exemplary implementations, the DC bias voltage is defined on the basis of a predicted DC voltage at an output node of the quasi-peak detection circuit in response to a noise level contribution of the signal analyzer when the detector diode is unbiased. A signal is propagated through the quasi-peak detection circuit after the detector diode is reverse-biased, followed by a noise floor adjustment procedure. The noise floor adjustment procedure includes an adjustment directed at least in part, at compensating for the DC bias voltage that is used to reverse-bias the detector diode.

Abstract: In an exemplary embodiment of the disclosure, a signal analyzer includes at least one noise reduction system in the form of an adaptive noise reduction system. The adaptive noise reduction system executes an adaptive noise floor extension (NFE) procedure that includes determining a predicted standard deviation of a response by the signal analyzer to intrinsic noise in the signal analyzer when various signal processing parameters desired by a user are applied to an input signal. The predicted standard deviation is then used in the signal analyzer to select and apply various noise subtraction values upon the input signal before displaying of a signal spectrum of the input signal upon a display of the signal analyzer. The adaptive NFE procedure is directed at reducing or eliminating various ambiguities and/or errors in the displayed signal spectrum.

Abstract: A user interface for an electronic instrument includes a display that displays a signal and a band marker. The band marker demarks a bandwidth of the signal by marking both a start frequency of the bandwidth and a stop frequency of the bandwidth. The electronic instrument performs a function on the bandwidth of the signal between the start frequency and the stop frequency.

Abstract: A method and apparatus compensates for phase noise added by a spectrum analyzer from phase noise measurements of a signal under test (SUT) taken by the spectrum analyzer. The method comprises the steps of measuring the phase noise of the SUT, determining the added phase noise of the spectrum analyzer, and applying a mathematical correction to the measured phase noise. A spectrum analyzer apparatus that compensates for added phase noise comprises a controller portion, a memory portion, a signal conversion and detection portion, and a compensation algorithm stored in the memory portion. A system that compensates for added phase noise comprises a controller having a control algorithm and a spectrum analyzer. The compensation and control algorithms are computer programs that implement the method of the present invention.

Abstract: A method and apparatus compensates for phase noise added by a spectrum analyzer from phase noise measurements of a signal under test (SUT) taken by the spectrum analyzer. The method comprises the steps of measuring the phase noise of the SUT, determining the added phase noise of the spectrum analyzer, and applying a mathematical correction to the measured phase noise. A spectrum analyzer apparatus that compensates for added phase noise comprises a controller portion, a memory portion, a signal conversion and detection portion, and a compensation algorithm stored in the memory portion. A system that compensates for added phase noise comprises a controller having a control algorithm and a spectrum analyzer. The compensation and control algorithms are computer programs that implement the method of the present invention.