Spectrum eyeglasses to provide a tranquilizing field of vision to the user are disclosed. The eyeglasses of the present invention comprise a frame mounted in front of the eyes of the user, an opaque wall supported by the frame positioned to prevent the entry of ambient light to the eye, a light source, a color wheel for selectively coloring light emitted from the light source, an opening formed in the opaque wall to expose the user's eye to a selectively varied field of color that is tranquilizi...

Disclosed is an adaptive filter for suppressing interfering narrow-band signals in a composite signal containing a desired broad-band signal. The adaptive filter is useful in a system which uses a broad-band signal and signal processing apparatus to derive information from the broad-band signal. In one embodiment the system makes use of a delay line to provide a delayed replica of the composite signal which is used to provide a correction signal to cancel the interfering narrow-band signal. The ...

A spectrum analyzer of the heterodyne type including a local oscillator having voltage controlled frequency, first mixer means coupled to receive a spectrum of input frequencies and to mix them with said frequency from the local oscillator and produce intermediate frequencies, narrow band filter means coupled to receive said intermediate frequencies and to select substantially one frequency thereof, second mixer means connected to mix said local oscillator frequency and the output of said filter...

A spectrum analyzer for measuring near-carrier spectrums utilizes only cld loop operation for measuring the spectral energy. Frequency modulated sidebands near a microwave frequency carrier can be examined without introducing any frequency translation byproducts which cannot be cancelled out of the measurement. A highly stable oscillator operating at a relatively low frequency has an output mixed with the input microwave carrier to provide a modulated output signal to a second mixer. The modulat...

A signal spectrum analyzer generates the discrete Fourier coefficients of a sampled-data signal applied as input thereto by repetitively passing sets of data points through the same configuration-invariant transform network to thereby achieve high transformation speed with minimal system complexity.

A continuous wave laser and modulator drives a fibre optic delay line whose output is detected by a photo detector and gain control amplifier. The signal from the amplifier is phase advanced in a modulator by a phase advance signal whose period is equal to the loop delay including the delay line. The resulting signal is added to an input signal in an adder whose output is the modulating signal for the modulator. Cycles of the phase advanced signal are counted to establish a processing time of N ...

A spectrum analyzer of the type where input signals to be analyzed are mixed with a repeatedly swept frequency signal so that output signals are provided which are time related to the frequency of the input signals. The repeatedly swept frequency signal is produced by applying a train of pulses to a dispersive delay via a bandpass filter having a characteristic such that the impulse spectrum of each of the pulses in the pulse train is reduced so as to match that of the dispersive delay. This inv...

A spectrum analyzer is provided in which a digital recirculating delay line memory is used in conjunction with a swept receiver to effect a time variant signal across a frequency range of interest. The swept receiver is fed analog signals for subsequent analog to digital conversion. Thereafter, a logic circuit simultaneously associated with a delay line memory, sweep receiver circuit and computer receives the converted digital signals. The logic circuit and an analog to digital converter are sim...

This spectrum analyzer will measure phase as well as amplitude of the speal components of a signal. This is done by measuring the phase difference between the spectral components which are separated by a fixed frequency. The input signal is mixed with a swept frequency of a local oscillator and the two components resulting therefrom are amplified and further mixed to obtain a frequency which is the difference of the two. This difference in frequency is measured by phase detectors so as to give a...

In a spectrum analyzer, an intermediate-frequency oscillator and the outputs from a sweep oscillator are frequency mixed to obtain a measuring signal, which is provided to a device under test. The intermediate-frequency signal and the output from the intermediate-frequency oscillator are supplied to a phase detector to detect a phase difference between them. A signal representing the detected phase difference and the output from a detector are selectively applied by a switch to a display.