28 results about "Passband filter" patented technology

This invention belongs to the field of microwave passive device technology and discloses a dual-passband millimeter-wave filter power divider based on a gap waveguide, comprising a metal bottom cover layer and a metal top cover layer arranged from bottom to top; wherein, the metal top cover layer includes a top cover and a top cover frequency division structure disposed on the top cover; the metal bottom cover layer includes a bottom cover and a bottom cover frequency division structure, a filtering structure, and a power divider network structure disposed on the bottom cover. The dual-passband millimeter-wave filter power divider based on a gap waveguide provided by this invention solves the technical problems of existing dual-passband filter power dividers, such as high design optimization requirements, narrow dual-frequency bands, difficulty in flexibly changing frequency bands, and high processing requirements.

The invention relates to the technical field of communication, in particular to a miniaturized wide-passband filter based on an EMSIW and a microstrip resonator. According to the miniaturized wide-passband filter, the two EMSIW cavities are adopted, the size of the filter can be effectively reduced, high-order modes TE120, TE210, TE220 and TE130 cannot be propagated in the EMSIW cavities, and therefore the filter has a wide stop band. Two microstrip resonators are embedded at a coupling window between two EMSIW cavities, and four-order quasi-elliptical filtering response is realized under the condition that no extra circuit area is occupied. Compared with other EMSIW filters, the filter has the advantages of being small in size, wide in passband, wide in stop band and good in selectivity, and has potential application value in a communication system.

Methods and apparatus for optical filtering are provided. In one example, an apparatus includes a spatial light modulator (102) having a two-dimensional array of square, rectangular, or rhombic pixels, and a controller (110) coupled to the spatial light modulator (102). The controller (110) may be configured to write image data (114) representing an image to the spatial light modulator (102) to control the spatial light modulator (102) to display the image for a frame period, and during the frame period, spatially reposition the image across a plurality of locations over the array of pixels, each single position of the plurality of positions is maintained for a respective time period, wherein the respective time period is selected according to one or more non-negative coefficients of an anti-aliasing filter transfer function (402).

An optoelectronic oscillator (100) and a signal processing method, which relate to the technical field of optoelectronics. In the optoelectronic oscillator (100), an electro-optical modulator (110), an optoelectronic detector (120), a first filter (130) and a power divider (140) form an optoelectronic oscillation loop. Compared with a conventional single-passband filter, the first filter (130) in the optoelectronic oscillation loop has an additional low-frequency passband, and thus can excite a pulse train of the low-frequency passband and a pulse train of a bandpass band in the optoelectronic oscillation loop. Since the oscillation of a pulse signal can automatically narrow a pulse train to form an ultrashort pulse train, when the pulse train excited by the bandpass band has undergone pulse narrowing by means of an oscillation mechanism in the optoelectronic oscillation loop, the pulse train excited by the low-frequency passband may further undergo pulse narrowing, such that the optoelectronic oscillator (100) can generate a microwave pulse train which is shorter than that of a conventional optoelectronic oscillator, that is, an ultrashort microwave pulse train.

The invention discloses a circuit and a method for improving interference of local oscillator phase discrimination stray on a receiver. The circuit comprises a clock input, a local oscillator unit, a filtering and amplifying unit and a frequency conversion unit which are connected in sequence. The filtering and amplifying unit is formed by connecting a pre-amplifier, an adjustable filtering unit and a post-amplifier in series; the adjustable filtering unit comprises a passband filtering and trap wave network to realize secondary suppression. The circuit can dynamically switch paths according to spurious offset, so that phase discrimination spurious is remarkably suppressed at a specific frequency point, local oscillator signals in a wide frequency range are compatible, low insertion loss and power fluctuation are kept, and the contradiction between bandwidth and performance is effectively balanced. The receiver local oscillator is realized by adopting conventional components and switch structures, does not need a special process, is easy to be integrated into an existing receiver local oscillator circuit, and has good compatibility.

The invention provides a photoelectric oscillator and a signal processing method. The invention relates to the technical field of photoelectricity, and in the photoelectric oscillator, an electro-optical modulator, a photoelectric detector, a first filter and a power divider form a photoelectric oscillation loop. Compared with a conventional single-passband filter, the first filter in the photoelectric oscillation loop has the advantages that a low-frequency passband is added, and a pulse sequence of the low-frequency passband and a band-pass passband can be excited in the photoelectric oscillation loop. Due to the fact that oscillation of the pulse signal can automatically narrow the pulse sequence to form the ultra-short pulse sequence, on the premise that the pulse sequence excited by the band-pass passband passes through an oscillation mechanism in the photoelectric oscillation loop to narrow the pulse, the pulse sequence excited by the low-frequency passband can further narrow the pulse, and the ultra-short pulse sequence is formed. Therefore, the photoelectric oscillator can generate a microwave pulse sequence which is shorter than that of a conventional photoelectric oscillator, namely an ultra-short microwave pulse sequence.

The invention provides a dual-passband filter. The dual-passband filter comprises a top metal layer, an upper dielectric plate, a middle metal layer, a lower dielectric plate and a bottom metal layer which are sequentially stacked from top to bottom, the middle metal layer comprises at least two capacitor loading patches; the metalized through hole array penetrates through the upper-layer dielectric plate and the lower-layer dielectric plate, the top end is connected with the top-layer metal layer, and the bottom end is connected with the bottom-layer metal layer; the at least two short-circuit conductive columns are located below the two capacitor loading patches respectively, the top ends of the short-circuit conductive columns are connected to the capacitor loading patches, and the bottom ends of the short-circuit conductive columns are connected to the bottom metal layer; the top metal layer comprises a resonance part, and the edge of the resonance part is provided with a first window. The dual-passband filter provided by the invention realizes independent regulation and control of dual passbands while satisfying miniaturization.

The invention relates to a flat passband filter circuit based on high-order cascading. The circuit comprises a high-order high-pass filtering module and a high-order low-pass filtering module which are cascaded in sequence to form a one-way processing path from a signal input end to a signal output end. Wherein the orders of the high-pass module and the low-pass module are not less than 6, and the cut-off frequencies of the high-pass module and the low-pass module are respectively set as the lower limit and the upper limit of a passband, so that a flat passband range is cooperatively defined. A Sallen-Key Butterworth structure is preferably adopted, and resistance-capacitance parameters of all levels are optimized, so that the excellent performance that the amplitude fluctuation in a passband is less than + / -0.5 dB and the roll-off rate of a transition band is greater than 80dB / octave is realized while high selectivity is ensured. The filter circuit provided by the invention effectively solves the contradiction between uneven passband and smooth transition band of the traditional band-pass filter, and is suitable for a precision electronic system with high requirements on signal fidelity and adjacent channel suppression.

According to the present disclosure, an acoustic wave filter is provided. The acoustic wave filter has a pass band and is configured to filter a radio frequency signal. The acoustic wave filter comprises a series resonator and a shunt resonator, the shunt resonator having a primary mode defined by a resonant frequency of the shunt resonator and a secondary mode defined by a longitudinal mode of the shunt resonator, the primary mode defining a lower edge of the pass band and the secondary mode being of a higher frequency than the primary mode. A corresponding radio-frequency module and wireless mobile device comprising said acoustic wave filter are also provided.

According to the present disclosure, a passband filter is provided. The passband filter has a series branch, where the series branch comprises a set of one or more resonators having a resonant frequency sufficiently away from the passband of the filter such that spurious modes, of the set of one or more resonators, that are associated with the resonant frequency are outside of the passband of the filter; a set of one or more reactive components in series with the set of one or more resonators, the set of one or more reactive components having a resonant frequency sufficiently away from the passband of the filter such that the spurious modes of the set of one or more reactive components, that are associated with the resonant frequency are outside of the passband, and such that the resulting combined resonant frequency of the series combination of the set of one or more resonators and the set of one or more reactive components is within the passband of the filter.

In one implementation, a wireless communication device includes a first transceiver configured to generate a transmit signal and a band pass filter (BPF) select circuit configured to filter the transmit signal by a one of a first BPF with a relatively high-frequency passband or a second BPF with a relatively low-frequency passband. The wireless communication device includes a second transceiver configured to receive a received signal filtered by the other one of the first or second BPF. Having the transmit and received signals filtered by two different passband filters improves the isolation between the transmitter and receiver. Another implementation configures the first transceiver to include its own set of first and second BPFs, and the second transceiver to also include its own first and second BPFs.

The invention provides a high-selectivity dual-passband filter based on a triangular hairpin ring resonator and a manufacturing method, and solves the problems that an existing dual-passband filter is large in circuit size, poor in passband control flexibility and insufficient in selectivity. The filter comprises a transmission line substrate, two microstrip feeder lines, two microstrip feeder lines and two triangular hairpin ring resonators. The resonators are connected through double hairpin structures to form a dual-mode resonator, are symmetrically distributed about the coupling gap, and realize electromagnetic coupling with the transmission line through the coupling gap. Two passbands are respectively formed by odd-mode resonance and even-mode resonance, and a transmission zero point is generated between the passbands by adjusting a coupling gap, so that the isolation and the selectivity are effectively improved. The overall size of the filter is only 17.45 mm * 8.7 mm, the dual-passband characteristic with the center frequency of 4.36 GHz and 6.85 GHz is achieved, the insertion loss is smaller than 0.2 dB, the return loss is superior to-20 dB, and the filter has the advantages of being small in size, high in selectivity, controllable in passband and the like. The method is suitable for the wireless communication fields of double-frequency wireless local area network (WLAN), satellite communication and the like.

An optical data receiver is configured for receiving optical signal comprising spectrally adjacent modulated subcarriers. The optical receiver includes an optical comb generator to output separate frequency tones, and a plurality of optical-to-electrical (OE) converters. The OE converters are configured to mix light of a plurality of the frequency tones with part of the received optical signal, and to output a temporal sequence of measurements of the mixture produced by said mixing. A digital signal processor is configured to recover a data stream carried by one of the subcarriers by performing multi-input multi-output (MIMO) processing using the temporal sequences of measurements output by at least two of the OE converters. The MIMO processing involves performing passband filtering for a passband wherein two of the subcarriers are down-converted by the mixing.

The embodiment of the utility model relates to the technical field of communication equipment, and particularly discloses a topological structure, a wide-passband filter and communication equipment, one end of a second parallel line is connected with one end of a first parallel line and one end of a first microstrip line, and the other end of the first parallel line is connected with a first open-circuit branch knot and an input end; the other end of the first microstrip line is connected with one end of a first short-circuit branch knot and one end of a second short-circuit branch knot, the other ends of the first short-circuit branch knot and the second short-circuit branch knot are respectively grounded, and the other end of the second parallel line is connected with one end of a second microstrip line and one end of a third parallel line; the other end of the second microstrip line is connected with one end of a third short-circuit branch and one end of a fourth short-circuit branch, the other end of the third short-circuit branch and the other end of the fourth short-circuit branch are both grounded, and the other end of the third parallel line is connected with the output end and the second open-circuit branch. Through the above mode, the embodiment of the utility model can obtain a miniaturized wide-passband filter based on the above topological structure design.

The application discloses an IPD dual-frequency passband filter chip and a radio frequency device, which comprises a substrate layer, a dielectric layer and an IPD dual-frequency passband filter circuit arranged on the substrate layer, wherein the IPD dual-frequency passband filter circuit comprises a signal input port, a filter network composed of lumped elements and a signal output port, and the filter network is connected with the input port and the output port through a first resonator and a second resonator respectively; the two passbands of the dual-frequency filter designed by the application have the characteristics of controllable bandwidth, good selectivity and strong out-of-band suppression capacity, and are suitable for miniaturized design of microwave circuits.

The application relates to a double-passband filter based on SISL, which comprises a five-layer dielectric substrate covered with metal layers on the top layer and the bottom layer, the five-layer dielectric substrate is sub1-sub5 from top to bottom, the metal layers on the top layer and the bottom layer of the five-layer dielectric substrate are G1-G10 from top to bottom, square metallized via arrays 1 are arranged in the middle regions of the five-layer dielectric substrate, the square metallized via arrays 1 on the five-layer dielectric substrate correspond to each other, an integrated DGS1 is arranged on the dielectric substrate sub1, a microwave circuit is arranged on the dielectric substrate sub3, an integrated DGS2 is arranged on the dielectric substrate sub5, air cavities are arranged on the dielectric substrate sub2 and the dielectric substrate sub4, the air cavity on the dielectric substrate sub2 and the air cavity on the dielectric substrate sub4 correspond to each other, the application realizes a double-passband filtering effect and improves the selectivity of the double-passband.

The invention relates to the technical field of plasma etching, and provides a radio frequency output device and semiconductor process equipment, and the device comprises a radio frequency source which is used for outputting a radio frequency signal; the filter is used for filtering interference reflected to the radio frequency source; and the frequency conversion circuit is connected with the radio frequency source through the filter and is used for adjusting the radio frequency so that the adjusted frequency is located outside the passband filtering range of the filter. By arranging the frequency conversion circuit, the output frequency of the radio frequency source can be adjusted, so that the reflection power of the plasma IMD is moved out of the filtering passband window of the filter corresponding to the radio frequency source in the frequency domain, and the influence of IMD reflection on the radio frequency source is avoided.

The invention discloses a switch filter bank in a ceramic substrate stacking form and an implementation method, and the switch filter bank comprises a first single-pole four-throw switch chip, a second single-pole four-throw switch chip and four ceramic filters with different frequency bands, namely a first pass-band filter, a second pass-band filter, a third pass-band filter and a fourth pass-band filter; wherein the two single-pole four-throw switch chips are in a mirror image relationship, and are switched to the same channel through a control signal; the first single-pole four-throw switch chip performs one-out-of-four on an input radio frequency signal to divide the frequency into four sections, the frequency is output through four ports of the switch, and the four ports are respectively connected with the four band filters for filtering; and then, the four pass-band filters are connected to a second single-pole four-throw switch chip for one-out-of-four output, so that the broadband radio-frequency signal is output after preselected and segmented filtering. The switch filter bank circuit is high in structural design integration level, reasonable in structure, small in plane size, low in cost and wide in output frequency, and miniaturization design of a radio frequency front-end circuit is facilitated.

This invention discloses a dual-passband filter based on integrated passive device technology. The invention achieves a dual-passband response by directly connecting a multi-mode resonator and a single-mode resonator, ensuring flexible adjustment of the two passbands without increasing insertion loss or excessive size. Each resonator has its own transmission zero, resulting in superior stopband suppression compared to traditional resonators without zeros. A hybrid coupling method, combining magnetic coupling and capacitance through partial overlap between inductors, introduces zeros, improving stopband performance without adding additional zero-point structures. The inclusion of a low-pass matching unit simultaneously improves passband matching and enhances stopband suppression, solving the problems of narrow high-frequency stopband suppression range and insufficient suppression in dual-passband filter chips.

The application belongs to the field of microwave technology, and particularly relates to a double-passband filter phase shifter with independent continuous tuning center frequency and insertion phase capacity. The center frequency and insertion phase of the two filter passbands in the phase shifter can be independently adjusted. By adjusting the bias state of each variable capacitance diode, various working modes can be realized, including: low-frequency passband insertion phase is unchanged, and high-frequency passband phase is continuously adjustable; high-frequency passband insertion phase is unchanged, and low-frequency passband phase is continuously adjustable; high-frequency passband remains unchanged, and low-frequency passband can still realize continuous phase adjustment after frequency shift; low-frequency passband remains unchanged, and high-frequency passband can still realize continuous phase adjustment after frequency shift. Thus, multi-band independent controllable application can be realized.

The invention discloses an optical fiber amplifier gain flatness control system and method based on sub-band detection, input signal light enters the input end of an optical fiber amplifier and then is divided into main signal light and input detection signal light, the input detection signal light is divided into three parts, the first part enters a photoelectric detector I, and the second part enters a photoelectric detector II; the second part enters a photoelectric detector III through a passband filter I, and the third part enters a photoelectric detector V through a passband filter III; the main signal light enters the light amplification light path to be amplified and then is divided into output detection signal light, the output detection signal light is divided into three parts, the first part enters the photoelectric detector II, the second part enters the photoelectric detector IV through the passband filter II, and the third part enters the photoelectric detector VI through the passband filter IV. According to the invention, the sub-band detection device is introduced into the optical fiber amplifier, the power distribution information of two-band optical signals is obtained in real time, the working parameters of the optical fiber amplifier are adjusted through calculation, and efficient gain planarization is realized.

The invention discloses a three-passband filter based on a micro coaxial transmission line. Comprising a micro coaxial outer conductor, a first inner conductor, a second inner conductor, a third inner conductor, a fourth inner conductor, a fifth inner conductor, a sixth inner conductor, a seventh inner conductor, an eighth inner conductor, a ninth inner conductor, a tenth inner conductor, a first long open circuit inner conductor, a second long open circuit inner conductor, a first short grounding inner conductor and a second short grounding inner conductor, according to the invention, a micro-coaxial transmission line structure is adopted as a whole, and miniaturization, high power capacity, good selectivity and a three-passband effect are realized by designing and optimizing a micro-coaxial topological structure and a geometrical shape and an arrangement mode of an inner conductor; and the difficulty that an existing filter is difficult to consider the size, the performance and the function integration level at the same time is overcome. The filter has the advantages of miniaturization, good out-of-band rejection characteristic and three passbands, and is suitable for a filtering scene in a radio frequency front-end system.

This invention discloses a three-channel dual-passband filter power divider, comprising three stacked metal layers and a dielectric substrate. The dielectric substrate contains four isosceles right-angled triangular substrate integrated waveguide resonant cavities enclosed by metallized vias. First and second resonant cavities of the same size are connected by their right-angled sides to form a first triangular unit; third and fourth resonant cavities of the same size but larger are also connected by their right-angled sides to form a second triangular unit, with the hypotenuses of the two units adjacent. By setting coupling windows between specific cavities and metallized via isolation walls between the third and fourth cavities, the first and second cavities collaboratively generate a first passband, and the third and fourth cavities collaboratively generate a second passband. The input port is located on the right-angled side of the first cavity, and the three output ports are located on the right-angled side of the second cavity, with isolation resistors connecting the ports. This invention highly integrates dual-passband filtering and three-channel power division functions, offering advantages such as compact structure, low insertion loss, and good output consistency.

The application discloses a sub-millimeter dual-passband filter transmission line based on a rectangular micro coaxial line, which comprises a micro coaxial outer conductor, a support strip, an inner conductor and a transition coaxial transition section arranged in the micro coaxial outer conductor, and adopts a micro coaxial inner and outer structure as a whole. The number, geometric shape and electrical characteristics of the micro coaxial inner conductor are designed and optimized to realize the filter effect of miniaturization and wide bandwidth under the sub-millimeter wave level size, overcome the defects of considering size and performance of the existing filter, and be used as a basic transmission line unit to construct various passive networks or directly feed an antenna to realize the filter characteristics from the transmission line level rather than the network level. The sub-millimeter dual-passband filter transmission line has low insertion loss, good out-of-band suppression characteristics and wide passband, and is particularly suitable for the filter application of low-frequency and millimeter wave high-frequency band signals in a wideband communication system.

The application provides a design method of an analog multi-passband filter. It is a hybrid method, which obtains a rough prototype of the analog multi-passband filter, and then fine tunes it until the equal ripple is realized in each passband. The rough prototype constructed by the analytic method contains important information of the analog multi-passband filter, effectively reducing the range of optimization and fine tuning. The method has fast convergence speed, and the performance of the designed analog multi-passband filter is flexible and controllable, including the number of passbands, the performance of each passband, the transmission zero point, and the complex response to meet more stringent technical requirements. Based on the filter polynomial derived by the design method of the analog multi-passband filter, various topological coupling matrices can be obtained for actual circuit implementation.

The application discloses a miniaturized three-passband filter of a substrate integrated waveguide built-in stripline resonator, which is composed of two SIW resonators, two one-end short-circuit and the other-end open-circuit lambda / 4 stripline resonators and two two-end open-circuit lambda / 2 stripline resonators, and the resonators form a three-passband filter in a series topology structure. The application utilizes the TE101 mode of the two SIW resonators, firstly, two one-end short-circuit and the other-end open-circuit lambda / 4 stripline resonators are symmetrically placed in the two SIW resonators to form a two-stage point and double-passband filter, and on the basis, the two one-end short-circuit and the other-end open-circuit lambda / 4 stripline resonators are coupled with the two two-end open-circuit lambda / 2 stripline resonators to form a two-stage point and three-passband filter. By embedding four stripline resonators in the SIW cavity, the miniaturization of the overall structure is realized, and the circuit area can be significantly reduced by about two-thirds while the number and order of passbands are maintained.

In certain embodiments, a system, a computer-implemented method, and computer-readable medium are disclosed for light efficient fluorescence imaging. The retina is flashed with broadband light and returned light is imaged after passing through one or more filters, such as notch filers, low-pass filters, and high-pass filters. Images may be captured with a single camera or at least two cameras, one capturing transmitted light from the filter and the other capturing returned light. Images may be combined by subtraction and / or addition to obtain a combined image representing light within a passband whereas no passband filters are used during imaging.

The submillimeter-level dual-passband filtering transmission line comprises a micro-coaxial outer conductor, a supporting strip, an inner conductor and a switching coaxial transition section, the supporting strip, the inner conductor and the switching coaxial transition section are arranged in the micro-coaxial outer conductor, and the whole submillimeter-level dual-passband filtering transmission line adopts a micro-coaxial inner and outer structure. By designing and optimizing the number, the geometrical shape and the electrical characteristics of the micro-coaxial inner conductors, the filter effects of miniaturization and wide bandwidth are achieved under the submillimeter wave level size, the defect that an existing filter gives consideration to both the size and the performance is overcome, and the filter can serve as a basic transmission line unit to be used for constructing various passive networks or directly feeding an antenna. And the filtering characteristic is realized from a transmission line level instead of a network level. The submillimeter-level dual-passband filtering transmission line has relatively low insertion loss, good out-of-band rejection characteristic and relatively wide passband, and is particularly suitable for filtering application of low-frequency and millimeter-wave high-frequency band signals in a broadband communication system.