4 results about "Selective filter" patented technology

This application discloses an anti-interference error monitoring device, method, system, and electronic device, relating to the field of anti-interference circuit technology. The device includes a signal generation unit, a frequency-selective filtering network, and a digital processing module. The signal generation unit outputs a reference signal for error calibration. The frequency-selective filtering network is disposed between the signal generation unit and the secondary side acquisition circuit of the instrument transformer, used to couple the reference signal and the power frequency signal to form a mixed signal. The frequency-selective filtering network includes an isolation capacitor and a tuning inductor connected in series with the isolation capacitor. The tuning inductor and the isolation capacitor are configured to resonate in series at the reference signal frequency, resulting in low impedance at that frequency and high impedance at the fundamental power frequency and / or higher harmonic frequencies. The digital processing module is used to extract the signal components in the mixed signal and determine the error parameters. This application can be used for online error monitoring of instrument transformers.

An electromagnetic wave absorber 500 comprises a frequency selective filter layer 400, a dielectric layer 200 positioned below the frequency selective filter layer 400, and a reflective layer 100 positioned below the dielectric layer 200. The reflective layer 100 includes a sheet-shaped first insulator 2 that has a first surface 3, and a first wiring pattern 11 that is provided on the upper surface of the first insulator 2 and is formed from fine metal wires 13. The first wiring pattern 11 has a first point 21, a first line 30 extending from the first point 21, and a second line 33 extending from the first point 21. The angle formed by the first line 30 and the second line 33 is greater than 0 degrees and less than 90 degrees, or is greater than 90 degrees and less than 180 degrees.

The application discloses a kind of mixing light module and passive optical network system, mixing light module includes shell assembly, light emitting receiving component being arranged in shell assembly, light emitting receiving component is equipped with optical port and lens, and is integrated with emitting unit and receiving unit.Emitting unit includes multiple laser assembly and wave combining component, and multiple optical signals are output from optical port after wave combining.Receiving unit includes wave separating optical separating component, first detection component and second detection component, wave separating optical separating component receives mixed frequency optical signal input from optical port, first, receive waveband and emission waveband are separated, then the optical signal of receive waveband is divided into first light beam and second light beam according to optical power, and first light beam and second light beam are respectively incident to two detection components in opposite directions.The application solves the technical problem that multiple system PON uplink signal cannot be independently separated by wavelength selective filter due to wavelength overlap by receiving mode of first wave separation and then light separation.

The present disclosure provides a compact fingerprint and finger vein combined scanner comprising a cemented prism pair (1') with first prism block (3) and second prism block (2), selective interference coating (7) between the prism blocks that transmits red wavelength light and reflects near-infrared wavelength light at different incidence angles, red LED (4) illuminating finger placement surface (6) on the first prism block (3), at least one near-infrared LED (5) illuminating the finger placement surface (6), imaging lens system (8) comprising First imaging lens (8a) and Second imaging lens (8b) arranged in sequence receiving light from the cemented prism pair (1'), aperture filter (9) between the imaging lens system (8) and imaging detector (10) with wavelength-selective filter transmitting red wavelength light and absorbing near-infrared wavelength light and central opening transmitting both wavelengths, and two-dimensional imaging detector (10) receiving light through the imaging lens system (8) and aperture filter (9).