31 results about "Dual band bandpass filter" patented technology

An image-sensing apparatus is provided. The image-sensing apparatus includes: an optical filter array including a two-band passing filter and an infrared filter; an RGB pixel array placed below the two-band passing filter; and a TOF pixel array adjacent to the RGB pixel array and placed below the two-band passing filter and the infrared filter, wherein a combination of the two-band passing filter and the infrared passing filter permits only the incident light in the infrared region to pass to the ToF pixel array.

A fluorescence detection optical system detects fluorescence beams with two or more different wavelengths and maintains a focal position through an automatic focusing function. A multi-channel fluorescence detection apparatus includes the fluorescence detection optical system. The fluorescence detection optical system includes an automatic focusing unit which receives light reflected off a microfluidic device and determines a focal point by using an astigmatic method or a knife edge method, and an actuator which adjusts a position of an objective lens according to control of the automatic focusing unit. In addition, the fluorescence detection optical system may include a plurality of dual band pass filters, dichroic devices, etc., which provide light beams emitted from at least two light sources and transfer fluorescence generated from the microfluidic device to a photodetector.

An eye tracking apparatus is operable in both first and second illumination environments where the second illumination is associated with a higher illumination environment than the first illumination. The apparatus includes an image capturer configured to capture an image of a user, an image processor configured to detect an eyepoint of the user in the captured image, and an optical source configured to emit infrared light to the user in a first illumination mode. The image capturer includes a dual bandpass filter configured to allow infrared light and visible light to pass.

A device for optical detection of a target gas in gas mixtures includes an operation and evaluation unit, a measurement cuvette with optically reflective surfaces on its interior walls and a gas inlet to the environment, a radiation source, a measuring detector and a reference detector unit provided on the measurement cuvette. The measuring detector and the reference detector unit detect the light of the radiation source and produce electrical signals corresponding to the intensity of the detected light. An optical bandpass filter element, constructed to transmit light of a measurement wavelength, is arranged upstream of the measuring detector. An optical double-bandpass filter unit, that transmits light of a first reference wavelength and light of a second reference wavelength, is arranged upstream of the reference detector unit. The operation and evaluation unit operates the radiation source and acquires the electrical signals of the measurement detector and the reference detector unit.

A dual-band bandpass filter with stepped-impedance resonators uses only one circuit to generate dual-band effect. It adopts the principle of stepped-impedance resonator, which contains a connecting section and two coupling sections. The impedance and electrical length of the connecting section and coupling sections conforms to a selected condition to generate two passbands at desired frequencies. A multi-layer broadside-coupled parallel lines structure may be applied to increase coupling-amount between the parallel lines so that the dual-band bandpass filters have broader bandwidth and less loss.

Two second-order bandpass filter are connected serially to obtain a dual bandpass filter. One is inductive and the other is capacitive. One has a low passband and the other has a high passband. Between them, a finite transmission zero is formed to suppress noise. The present invention achieves a passband as wide as 1 gigahertz so that it can be applied to a wireless local network, communication equipments and electronic devices.

The invention discloses a dual-band bandpass filter based on a single rectangular SIW structure. The present invention is based on a rectangular SIW structure and controls the first four resonant modes of the filter, namely TE101, TE201, TE301 and TE401 modes, by using a method of metal via disturbance. TE101 and TE201 combine to form a first passband, TE301 and TE401 combine to form a second passband. In addition, the bandwidth and spacing of the two passbands can be tuned relatively independently by disturbing vias through movement. At the same time, the offset input and output feeders introduce four transmission zeros into the filter, which improves the stopband attenuation of the filter. By utilizing single SIW cavity mode reasonably, it meets the miniaturization requirement of modernmulti-standard RF system and solves the problems of large size and complex design of a traditional dual-band filter.

The invention relates to a bent dual-band bandpass filter applying a defected ground level waveguide technology, which comprises an upper surface micro-band part and a defected ground level waveguide structure of a ground part, wherein the upper surface micro-band part comprises a micro-band input port (1), a micro-band output port (2) and a pair of T-shaped coupling arms (3) and (4), wherein the input port (1) is coupled to the defected ground level waveguide structure of the ground through the coupling arm (3), and the output port (2) is coupled to the defected ground level waveguide structure of the ground through the coupling arm (4); and the defected ground level waveguide structure of the ground part is formed by bending and winding a big square defected ground level waveguide ring into three square defected ground level waveguide rings, wherein the three square defected ground level waveguide rings are respectively a defected ground waveguide square ring (5) which is positioned at the outermost layer, a defected ground waveguide square ring (6) which is bent inward and is positioned at the middle layer, and a defected ground waveguide square ring (7) which is bent inward and is positioned at the innermost layer. The invention is applied in intensive integrated circuits.

An integrated antenna unit where two dual-polarized radiating elements are connected on a PCB serving reflecting board as well as a filter lid of two-band pass filters. Each of two band-pass filter is connected directly to a two-way power splitter serving connection of same polarization from the two radiating elements. Two walls running parallel are extending at the band-pass filter edges to support the cavity of the filters and at same time serving as reflecting walls enabling to control the 3 dB azimuth beam generated by the radiating elements. Next, a multi-array antenna by collocating multiple arrays of the integrated antenna units.

A fluid identification assembly is provided to determine the presence or absence of multiple components within a fluid in a conduit. The assembly includes a light source and a light detector positioned to receive a portion of light from the light source reflected by the conduit and fluid. A dual-band bandpass filter may be associated with the light detector to allow multiple wavelengths of light to be monitored, thereby monitoring the composition of the fluid based on the amount of light of each wavelength absorbed by the fluid. Rather than a dual-band bandpass filter, a second light detector may be provided, along with a beam splitter to separate light from a single source for receipt of light of different wavelengths by the light detectors. The dual-band bandpass filter may also be replaced by a second light source and detector pair for analyzing fluid using multiple wavelengths of light.

The invention discloses a double-frequency phase locking method based on a dual-band-pass filter. The double-frequency phase locking method is applied to extraction of positive and negative sequence component amplitudes, phase positions and frequencies under unbalanced states of network voltages. According to the method, two new transformational matrixes T+' and T-' are established to extract double-frequency fluctuation Vd+' and Vq+' both generated by a network voltage positive sequence component and double-frequency fluctuation Vd-' and Vq-' both generated by a network voltage negative sequence component, the dual-band-pass filter is used for extracting a double-frequency component, and the phase positions of the network voltage positive sequence component and the network voltage negative sequence component are locked accurately when the double-frequency component is locked accurately. By the double-frequency phase locking method, detection speed and accuracy of the positive and negative sequence component amplitudes, the phase positions and the frequencies can be improved; in terms of new energy grid connection and situations in need of quick extraction of the positive sequence component and the negative sequence component, the double-frequency phase locking method has a certain engineering application value.

The invention relates to an HMCSIW double-band-pass filter loaded with L-shaped branch lines, which takes an HMCSIW as a basic transmission line and comprises a dielectric substrate, a top metal layer arranged on the upper surface of the dielectric substrate and a bottom metal layer arranged on the lower surface of the dielectric substrate, and a plurality of U-shaped slots are etched on the top metal layer of the dielectric substrate, so that a broadband mother filter is realized; two L-shaped branch lines are loaded on the wide side of the top metal layer, the distance between the two L-shaped branch lines is used for generating a transmission zero point, two sets of gradually-changed rectangular grooves are etched in the bottom metal layer of the dielectric substrate and are divided into transition areas located at an input port and an output port, and the stop-band bandwidth is widened. Three U gaps are introduced into the upper surface of the HMCSIW to realize a broadband mother filter, a source and a load are coupled through two L-shaped branch lines, a transmission zero point is generated, a mother passband is split into two sub passbands, and finally the dual-passband filter is constructed.

The invention provides a photonic crystal double-band-pass filter which comprises a first metal plate, a second metal plate, metal columns and defect metal columns, the first metal plate and the second metal plate are correspondingly arranged, and the metal columns are arranged between the first metal plate and the second metal plate in a two-dimensional periodic mode. Two opposite ends of the metal columns are respectively contacted with the first metal plate and the second metal plate to form a metal column array; the height of the defective metal columns is smaller than that of the surrounding metal columns, the defective metal columns comprise first defective metal columns and second defective metal columns which have different cross sectional areas so as to form defective sub-periodic structures, and the defective sub-periodic structures are arranged in the metal column array in a two-dimensional periodic mode. The invention provides a photonic crystal double-band-pass filter which can be used for 6G communication and optical communication in the future, and fills the blank in the field.