Embodiments of this invention include a test and measurement instrument and associated methods for acquiring and stitching wide overlapped non-uniform frequency bands so that a user specified band can be efficiently displayed and analyzed. The test and measurement instrument includes a user interface to receive the user specified frequency span. Acquisition circuitry acquires one or more predefined frequency bands having non-uniform overlapping frequency ranges. A frequency band processing section can decimate the acquired frequency bands, mask the acquired frequency bands, and stitch the masked frequency bands together. A display section displays the user specified frequency span using the stitched frequency bands. Due to the overlap configuration of the wide non-uniform bands, any user specified span between 50 kHz and 6 GHz, or thereabout, can be covered by two bands.

A wideband device for the spectral analysis of a signal of interest includes a source designed to generate the signal of interest; an optical splitter element designed to spatially split the signal of interest into a first signal and a second signal; a first frequency-shifting optical cavity comprising a first frequency shifter designed to shift the optical frequency of the first signal by a first frequency f.sub.1 per round trip in the first cavity, the first cavity having a first trip time .sub.1; a second frequency-shifting optical cavity comprising a second frequency shifter designed to shift the optical frequency of the second signal by a second frequency f.sub.2 per round trip in the second cavity, the second cavity having a second trip time .sub.2; the first and the second optical cavity being designed such that a maximum number of round trips of the signal in the first and the second cavity is equal to predetermined N; a detector designed to coherently detect the first signal transmitted by the first cavity and the second signal transmitted by the second cavity and generate a photocurrent proportional to a luminous intensity detected by the detector, an analog low-pass filter designed to filter frequencies of the photocurrent that are lower than min (f.sub.1/2, f.sub.2/2) a processor configured to compute a square modulus of the photocurrent filtered by the low-pass filter, from which a temporal representation of frequency information of the signal of interest is determined.

The present invention provides a filter bank circuit capable of measuring or testing a frequency band, a spectrum analyzer, a signal analyzer, a signal generator using the filter bank circuit, and a method for controlling the filter bank circuit. A filter bank circuit 10 includes, for example, a one-pole two-throw changeover switch 20 and filter groups G1 and G2, each of which has m filters. The passbands of the filters included in each filter group do not overlap with each other, and the adjacent passbands of the filters included in all the filter groups overlap with each other.

The present invention provides a filter bank circuit capable of measuring or testing a frequency band, a spectrum analyzer, a signal analyzer, a signal generator using the filter bank circuit, and a method for controlling the filter bank circuit. A filter bank circuit 10 includes, for example, a one-pole two-throw changeover switch 20 and filter groups G1 and G2, each of which has m filters. The passbands of the filters included in each filter group do not overlap with each other, and the adjacent passbands of the filters included in all the filter groups overlap with each other.

A measurement system includes a narrowband receiver configured to receive an input signal with an initial bandwidth. The narrowband receiver includes at least one local oscillator configured to provide a local oscillator signal having a center frequency and at least one signal mixer configured to mix the input signal and the local oscillator signal to obtain a mixed signal including image portions. The mixed signal has a respective center frequency in view of the local oscillator signal mixed therein. The narrowband receiver is configured to process two or more mixed signals, thereby obtaining two or more captured signals for different center frequencies of the local oscillator signal. The two or more captured signals have a limited bandwidth compared to the initial bandwidth. The narrowband receiver is configured to combine the two or more captured signals in order to obtain a processed signal without image portions.

A spectrum analyzer (10) comprises a signal input or receiver (11) for receiving a signal, an A/D converter (12) configured to sample the received signal and generate a data stream of IQ-data, a digital processing circuit (13) for generating compressed data from the data stream of IQ-data, and a data interface (19) for outputting the compressed data from the spectrum analyzer (10).

A spectrum analyzer (10) comprises a signal input or receiver (11) for receiving a signal, an A/D converter (12) configured to sample the received signal and generate a data stream of IQ-data, a digital processing circuit (13) for generating compressed data from the data stream of IQ-data, and a data interface (19) for outputting the compressed data from the spectrum analyzer (10).

Disclosed is a channel-selective RF power sensor having a coupler and a channel-selective power measurement circuit. The said coupler is configured to obtain a sample of energy travelling on a main transmission line and provide the sample of energy to the channel-selective power measurement circuit. The sample of energy has a channel of interest. The channel-selective power measurement circuit is configured to measure RF energy information for the channel of interest in the sample of energy. Also disclosed is a method of measuring RF energy information for a channel of interest. The method includes providing a channel-selective RF power sensor and a main transmission line and obtaining a sample of energy from the main transmission line using a coupler of the channel-selective RF power sensor.

Disclosed is a channel-selective RF power sensor having a coupler and a channel-selective power measurement circuit. The said coupler is configured to obtain a sample of energy travelling on a main transmission line and provide the sample of energy to the channel-selective power measurement circuit. The sample of energy has a channel of interest. The channel-selective power measurement circuit is configured to measure RF energy information for the channel of interest in the sample of energy. Also disclosed is a method of measuring RF energy information for a channel of interest. The method includes providing a channel-selective RF power sensor and a main transmission line and obtaining a sample of energy from the main transmission line using a coupler of the channel-selective RF power sensor.