66 results about "Dual band filter" patented technology

A dual band full duplex mobile radio is provided that includes a transmit portion including a dual band filter and a receive portion including a dual band filter. The dual band full duplex mobile radio further includes a circulator connecting the transmit portion and the receive portion and configured to provide transmit and receive switching.

The invention discloses a differential dual-band filtering antenna. The differential dual-band filtering antenna comprises a first substrate, a first radiating unit, a first feeding line, a first dual-band filter, a second substrate, a second radiating unit, a second feeding line, a second dual-band filter, an H-shaped grounding plate and a director, wherein the first radiating unit, the first feeding line and the first dual-band filter are arranged on an upper surface of the first substrate, the first dual-band filter is inserted into the first feeding line, the second substrate is opposite to the first substrate, the second radiating unit, the second feeding line and the second dual-band filter are arranged on a lower surface of the second substrate, the second dual-band filter is inserted into the second feeding line, the H-shaped grounding plate and the director are arranged between a lower surface of the first substrate and an upper surface of the second substrate, the two groups of radiating units are symmetrically arranged relative to the first feeding line and the second feeding line, and the two groups of dual-band filters are arranged in a lamination way and are connected to the H-shaped grounding plate through via holes. A coupling between resonators of the dual-band filters is formed by folding, a radiating zero point can be introduced to the exterior of two frequency bands of the filtering antenna, the selectivity of the filtering antenna is improved very well, and moreover, the impedance bandwidth of the filtering antenna can be improved by adjusting the positions of the dual-band filters inserted into the feeding lines.

The invention relates to an ultra-narrow bandwidth dual-band filter based on an asymmetric step impedance resonator. The ultra-narrow bandwidth dual-band filter comprises a medium substrate, a micro-strip line on the upper surface of the medium substrate and a grounding metal coating on the lower surface of the medium substrate. The micro-strip line on the upper surface of the medium substrate consists of two identical asymmetric step impedance resonators A and B, an input feed line and an output feed line. The resonator A is folded with the resonator B into a spiral shape, the resonators A and B are mutually coupled with each other in a weak manner, and the input and output feed lines are respectively coupled with the resonators A and B to feed. The dual-band filter in the embodiment has a small size and good frequency selectivity, low insertion loss inside a pass-band and high attenuation outside the pass-band can be realized, and the ultra-narrow bandwidth dual-band filter can be used for the design of a ultra-narrow bandwidth miniaturized dual-band filter in a wireless communication system.

A switchable dual-band filter comprises first and second switchable resonators, a coupling structure having two ends respectively connecting the first and the second switchable resonators, an input impedance conversion circuit connecting an input terminal and the first resonator, and an output impedance conversion circuit connecting an output terminal and the second resonator. The coupling structure couples the first resonator to the second resonator, and vice versa. The input / output impedance conversion circuit converts the impedance on the input / output terminal into two distinct impedances that correspond to a first and a second operating frequency. The filter is simple in structure, occupies a smaller circuit area, and is cost-effective in manufacturing. The impedance at both operating passbands can also be matched properly.

The invention discloses a dual-band filter applied to the communication field. The dual-band filter comprises a medium substrate provided with a grounding through hole, a main circuit located on the upper surface of the medium substrate, and a metal floor located on the lower surface of the medium substrate. The main circuit is formed by concatenation of two dual-band resonators arranged in an axial symmetry mode, the two dual-band resonators are connected through the grounding through hole, and each dual-band resonator is connected with an input transmission line or an output transmission line. Each dual-band resonator comprises a low-impedance transmission line, an L-shaped short circuit high-impedance transmission line and an open circuit transmission line, wherein the L-shaped short circuit high-impedance transmission line and the open circuit transmission line are respectively connected on the low-impedance transmission line. The dual-band filter overcomes the defects that a traditional dual-band filter is complex in structure, large in size and the like, and has the advantages of being high in frequency selectivity, good in interband isolation performance, compact in structure and small in size, and center frequency and bandwidth can be controlled easily.

The invention discloses an RQMSIW-based ultra-compact dual-band band-pass filter. The RQMSIW-based ultra-compact dual-band band-pass filter is based on a QMSIW structure, a ridge waveguide is loaded therein, so that the filter generates a resonance characteristic similar to a rectangular cavity, an open circuit strip line is embedded in the lower side of the ridge waveguide, a higher mode, i.e., aTE201 mode, of the filter is excited, dual-band response is generated, and two stubs loaded on the strip line are used for improving performance of a second frequency band. The dual-band filter is realized in the QMSIW structure for the first time, thereby providing a new idea for studying an SIW structure-based dual-band filter.

The present invention discloses a planar wide stopband double-frequency filter, which is fabricated on a dielectric substrate in the manner of a printed circuit board. On the same surface of the dielectric substrate, the following elements are formed respectively: a feeder port (port1) and a feeder port (port2) for inputting or outputting the electromagnetic wave signals, a first port feeder, a second port feeder, a first resonator R1, a second resonator R2, and a third resonator R3. All the resonators are located between the first port feeder and the second port feeder; the first resonator R1 and the third resonators R3 are of the same structure and of the same impedance at every part and are placed mirror-like with respect to the second resonator R2. The resonators are all stub-loading resonators and each consists of a half-wavelength resonator and a loading open stub respectively. Through the adopting of two different resonators to obtain the double-frequency filter, the invention uses symmetrical stub-loading resonators to realize double-frequency characteristics and overcomes the interference of harmonic waves and clutter signals to obtain a relatively wide stopband.

The invention relates to a packaged planar integrated gap waveguide dual-band filter, and the filter comprises three dielectric plates bonded together. The upper surface of the bottom dielectric plateis printed with a metal layer, and the metal layer is provided with a rectangular gap. Two ends of the metal layer are respectively connected with a transition gradual change line and a feed microstrip line, and the lower surface is printed with a grounding metal layer. Two sides and the center of the bottom dielectric plate are respectively provided with periodic metal via holes through perforation, thereby implementing an SIW filter. The upper surface of the top dielectric plate is printed with a metal layer, and the lower surface is printed with a metal circular patch, and the dielectric plate is provided with a periodic metal via hole through perforation, thereby forming an artificial magnetic conductor structure. The central dielectric plate separates the top dielectric plate and thebottom dielectric plate. According to the invention, the dual-band filter packaged through AMC is achieved, and the invention solves the problems of radiation loss and plane waves in a conventional filter. Meanwhile, the filter is small in gap, and is stable in structure.

The invention relates to a film structure for a filter and a triple-band filter utilizing the film structure. The film structure for the filter is (alpha H beta L) (N)|Sub|(LH) (N), wherein Sub represents a substrate, H represents a ZnS film layer, L represents a YbF3 film layer, N represents periodicity, and alpha and beta represent optical thickness coefficients of the film layer. The film structure for the filter is weak in susceptibility and easily plated; and the film layer has the advantages of high mechanical strength, good matching of internal stress, strong binding ability with the substrate and the like. According to the triple-band filter utilizing the film structure, the micro transmission to lasers in wavelengths of 1.064mum and 1.57mum is realized, wherein the transmissivity satisfies that T is more than or equal to 7% and less than or equal to 13%; and meanwhile, high transmission to bands in a wavelengths of 7.7-10.5mum is realized, and the average transmissivity T is more than or equal to 98%.

A dual-band filter and method thereof include a diplexer configured to process one of a first band signal and a second band signal, which includes a frequency band different from a frequency band of the first band signal, and block the other of the first band signal and the second band signal. A balun is configured to convert the first band signal from a differential signal to a single signal in response to the first band signal being transmitted, and convert the first band signal from a single signal to a differential signal in response to the first band signal being received. A direct current (DC) voltage supply port configured to supply a DC voltage to the balun when the first band signal is received.

The invention discloses a dual-frequency filter and a mobile terminal, and the dual-frequency filter comprises a metal cavity formed by a cavity surface with five outer walls printed with metal and acoplanar waveguide, and a metal plate parallel to the coplanar waveguide is arranged in the metal cavity. The metal plate is provided with three slot lines parallel to the two long end faces of the metal plate, and the central positions of the two long end faces are respectively connected with the central conductor band of the coplanar waveguide through a metal patch. Compared with the prior art,the filter has the advantages that controllability of high-pass band width and low-pass band width is achieved, the designed filter can generate two transmission zero points between a high-pass band and a low-pass band and has the advantages of being small in size, high in return loss, good in inter-band isolation effect performance and the like, on one hand, hardware occupied space of the whole device is saved, and on the other hand, better performance experience can be provided.

A signal input / output line 101 is used for input and output of a signal. A first resonating part 102 is connected to the signal input / output line 101 at one end and is opened at the other end. A second resonating part 103 is connected to a ground conductor 105 at one end and is opened at the other end. A connecting line 104 has a predetermined length and is connected to a point of connection between the signal input / output line 101 and the first resonating part 102 at one end and is connected to a predetermined point on the second resonating part 103 at the other end.