37 results about "Band notch" patented technology

The present invention discloses an antenna for ultra-wideband (UWB) communication having a band-stop characteristic. According to an embodiment of the present invention, the UWB antenna is a patch antenna employing microstrip feeding. In order to expand a bandwidth at a low frequency band, a stub is formed in a radiating element. Furthermore, since steps are formed in a ground plane, an antenna characteristic at an intermediate frequency band can be improved and a UWB characteristic can be obtained. According to another embodiment of the present invention, the UWB antenna is a patch antenna employing microstrip feeding and has a recess formed in the ground plane, thereby implementing the UWB characteristic. The antenna of the present invention has an inverse U-shaped slot formed in the radiating element, thus implementing the band-stop characteristic at the UNII band. In addition, the antenna of the present invention has includes a ground plane having a small area and has omnidirectional radiating patterns accordingly.

An ultra-wideband (UWB) antenna is provided. It comprises a dielectric substrate, a ground plate, a metal plate, and a transmission line. The ground plate formed on the dielectric substrate has a first slot thereon. The metal plate formed on the dielectric substrate has a feed-point and a second slot thereon. The total length of the second slot is about a half-wavelength at the desired notched frequency for the UWB antenna. By embedding the second slot of a suitable length on the metal plate resided in the first slot, a band notched characteristic is achieved for the antenna in the 5 GHz band, thereby overcoming the problem of signal interference with the UWB operations. The disclosed antenna and the circuitry for the antenna system are easily integrated. With the simple structure, the fabrication cost for the antenna is also reduced.

The invention discloses a periodic-structure vibration isolation device which comprises two panels, multiple vertical rods and multiple oblique rods, wherein the two panels are arranged at intervals; one panel is connected with equipment which needs vibration isolation through a vibration isolator, and the other panel is connected with a mounting base by virtue of a vibration isolator; the multiple vertical rods are arranged in an array and are vertically arranged between the two panels so as to form multiple vibration isolation regions, reinforced rib plates are arranged at connection parts between all vertical rods in each vibration isolation region and the upper and lower panels; one oblique rod is arranged between every two reinforced rib plates which are arranged in opposite angles of each vibration isolation region, and the oblique rods in the two adjacent vibration isolation regions are arranged symmetrically relative to the common vertical rod, so that a vibration isolation structure with periodic arrangement is formed, the band notched characteristic of the periodic structure is formed and effective vibration isolation and noise reduction are realized. The device is capable of not only providing sufficient static rigidity and dynamic rigidity, but also effectively isolating low-frequency narrow-band line spectrums and wide-band vibration transfer which are generated by main and auxiliary mechanical devices and restraining noise radiation caused by vibration transfer.

A filtering apparatus and method for dual-band sensing circuit are disclosed. The invention features a dual-band sensing unit disposed in a filtering device that receives the signals from a sub-system with variable frequency spectrum. The signals are split up into several bands. After that, one or more frequency detecting units are used to detect the power of high-band and low-band signals, and convert the power into a voltage signal. Users can externally adjust the gain of a tunable gain amplifier for the voltage signal. Further, a comparison operation is processed by a comparator, and a signal resulted from the comparison operation is used to control the switch timing for an RF switching unit. Consequently, this like adaptive notch filter is achieved to determine the intensity of noise and thereby to turn on the high-band or low-band notch filters, so as to reduce the in-band loss.

The present invention discloses an antenna for ultra- wideband (UWB) communication having a band-stop characteristic. According to an embodiment of the present invention, the UWB antenna is a patch antenna employing microstrip feeding. In order to expand a bandwidth at a low frequency band, a stub is formed in a radiating element. Furthermore, since steps are formed in a ground plane, an antenna characteristic at an intermediate frequency band can be improved and a UWB characteristic can be obtained. According to another embodiment of the present invention, the UWB antenna is a patch antenna employing microstrip feeding and has a recess formed in the ground plane, thereby implementing the UWB characteristic. The antenna of the present invention has an inverse U-shaped slot formed in the radiating element, thus implementing the band-stop characteristic at the UNII band. In addition, the antenna of the present invention has includes a ground plane having a small area and has omnidirectional radiating patterns accordingly.

The invention relates to the design of a notch ultra-wideband antenna and belongs to the technical field of propagating and receiving electromagnetic waves. The invention provides a novel multi-notch ultra-wideband antenna with stop-band units simultaneously loaded to a feeder and a radiation patch; specifically speaking, an open slot of 1 / 4 wavelength is formed in the radiation patch and C-shaped half-wavelength open-circuit resonance units different in size are loaded at the two sides of the feeder, and therefore, a three-stop-band notch ultra-wideband antenna is realized; the three-stop-band notch ultra-wideband antenna is capable of filtering out interferences from WiMAX (Worldwide Interoperability for Microwave Access) (3.3-3.6GHz) and WLAN (Wireless Local Area Network) (5.15-5.35GHz, 5.725-5.825GHz) systems. The antenna has the advantages of independently adjustable frequency point of each stop-band and independently adjustable bandwidth of each stop-band. Simulation results and actual measurement results prove excellent multi-frequency filter characteristic of the antenna.

A DC block with a band-notch characteristic using a defected ground structure (DGS), includes a pair of coupled lines for being formed parallel to each other on one surface of a dielectric and blocking a flow of a DC, and at least one DGS for being formed on an area of the rear surface of the dielectric corresponding to each coupled line and comprising an etched region formed by etching a part of a ground surface bonded to the dielectric and a metal region formed in the etched region. Accordingly, the stop band of the desired bandwidth in the desired communications band can be formed and the size of the communications system can be reduced.

The invention discloses a small UWB (ultra-wideband) antenna with band-notch characteristics in multiple frequency bands. The antenna comprises an earth plate, a dielectric substrate, a feed network and a radiation patch, wherein the earth plate is arranged on one side of the dielectric substrate, the feed network and the radiation patch are arranged on the other side of the dielectric substrate, the radiation patch adopts a rectangular structure with a step-shaped bulge, the step-shaped bulge end of the radiation patch is connected with the feed network, a U-shaped groove and a T-shaped groove are etched in the radiation patch, and the feed network comprises microstrip lines. The antenna can effectively inhibit interference of signals from various narrow-band systems of WiMAX wireless communication in a work frequency band ranging from 3.3 GHz to 3.7 GHz, C-band satellite communication in a downlink frequency band ranging from 3.7 GHz to 4.2 GHz, digital microwave communication in the work frequency band ranging from 4.3 GHz to 4.5 GHz, large-capacity microwave communication in the work frequency band ranging from 4.4 GHz to 5.0 GHz, a part of WLAN (wireless local area network) wireless communication in the work frequency band ranging from 5.15 GHz to 5.35 GHz, to the UWB system. The antenna is small in size, simple in structure, easy to manufacture and wear, good in performance and capable of being applied to various UWB communications.

A DC block with a band-notch characteristic using a defected ground structure (DGS), includes a pair of coupled lines for being formed parallel to each other on one surface of a dielectric and blocking a flow of a DC, and at least one DGS for being formed on an area of the rear surface of the dielectric corresponding to each coupled line and comprising an etched region formed by etching a part of a ground surface bonded to the dielectric and a metal region formed in the etched region. Accordingly, the stop band of the desired bandwidth in the desired communications band can be formed and the size of the communications system can be reduced.

The invention discloses a gain band-notched characteristic filtering antenna. The gain band-notched characteristic filtering antenna includes a dielectric substrate, wherein a slot line, a first disturbance stub and a second disturbance stub; the slot line is perpendicular to a central axis of the dielectric substrate, and is symmetrical with the central axis of the dielectric substrate; the structure and the size of the first disturbance stub are identical to the structure and the size of the second disturbance stub; and the first disturbance stub and the second disturbance stub are respectively arranged at two sides of the central axis of the dielectric substrate, and perpendicularly intersect with the slot line. On the premise of not introducing an additional resonator and not damaging the antenna impedance frequency response continuity, the gain band-notched characteristic filtering antenna can achieve the filtering effect by means of regulation and control of the intrinsic radiation mode of the antenna, and has the advantages of being simple in structure, being low in manufacturing cost, and having a wide application prospect in the wireless communication field.

The invention relates to a miniaturized wide-stopband ultra-wideband filter with dual band-notched characteristics. The filter comprises a first input / output port, a second input / output port, and a dielectric substrate. A top micro-strip structure and a bottom metal grounding structure of the dielectric substrate are connected. The top micro-strip structure comprises a first uniform transmission unit, a second uniform transmission unit, a parallel coupling line unit I, a parallel coupling line unit II, and a ring resonator. The first input / output port is connected with one end of the first uniform transmission line unit, and the other end of the first uniform transmission line unit is coupled to one end of the ring resonator. The second input / output port is connected with one end of the second uniform transmission line unit, and the other end of the second uniform transmission line unit is coupled to the other end of the ring resonator. By designing the ring resonator to be of a folding structure and arranging the two input / output ports on the same side of the dielectric substrate, the filter is miniaturized. The filter has the advantages of compact structure, high frequency selectivity and wide stopband rejection.

The invention relates to an ultra-wideband antenna with double notch characteristics. The antenna comprises a top radiation patch layer, an intermediate dielectric substrate and a bottom grounding plate. The top radiation patch layer, the intermediate dielectric substrate and the bottom grounding plate are tightly connected to form an antenna whole body, wherein the top radiation patch layer is connected with a microstrip transmission line, a C-shaped gap with an upward opening is etched in one side, close to the microstrip transmission line, of the top radiation patch layer so as to realize WLAN frequency band notch characteristics, and a right-angle U-shaped gap is etched in the microstrip transmission line so as to realize X-band notch characteristics. According to the invention, the notch effect of the antenna can be improved, so that the antenna forms good notch characteristics in two narrow-band frequency bands of a wireless local area network and an X-band satellite.

The invention discloses an ultra wideband antenna based on a gradient step structure. The ultra wideband antenna has band-notched characteristic in the WLAN (wireless local area network) frequency band. The ultra wideband antenna consists of a dielectric substrate (1), a radiation patch unit (2), a U-shaped structural slot (3), a micro-strip transmission line (4) and a grounding surface (5). The radiation unit, the micro-strip transmission line and the U-shaped structural slot are all printed on the upper surface of the dielectric substrate. The ultra wideband antenna based on the gradient step structure has the advantages that the structure is compact, the size is small, and the band-notched frequency can be adjusted by changing the size and position of the U-shaped structural slot, so that the problem of same frequency interference in an ultra wideband communication system is solved.

The invention discloses a small ultra wideband band-notched antenna with controllable second-order notched bandwidth. The antenna is printed on a dielectric slab, and comprises a step change width gap formed in the front surface of the dielectric slab, a microstrip feeder arranged on the back of the dielectric slab, a terminal-open quarter-wavelength gap formed in the back of the microstrip feeder, and a terminal-short half-wavelength gap formed beside the step width gap. The electromagnetic wave on the microstrip feeder is coupled onto the step width gap and radiated out; the quarter-wavelength gap is perpendicular to the microstrip feeder; and the quarter-wavelength gap and the half-wavelength gap form two resonators coupled with each other in the notched frequency band. due to the antenna provided by the invention, the technical problems of large size, uncontrollable notched bandwidth and poor selectivity of the existing ultra wideband antenna are solved, the selectivity of notched waves and the controllability of second-order bandwidth are improved greatly, and the anti-interference effect is good.

The invention discloses a band-notched ultra wideband antenna, which consists of a medium substrate (1), a radiation unit (2) and a signal feed band wire (3); an SIR-DGS structure slot (4) is formed in the radiation unit. The radiation unit and the signal feed band wire are printed on the upper surface of the medium substrate, the radiation unit is positioned in the middle of the medium substrate; a feeder is led to the radiation unit from the edge of the medium substrate and is connected with the medium substrate; a grounding surface is printed at the lower surface of the medium substrate. The band-notched ultra wideband antenna is compact in structure and small in size, band-notched frequency can be adjusted by changing the size and position of the SIR-DGS structure slot, and the problem of same frequency interference of an ultra wideband communication system is solved.

The invention discloses a UWB (ultra-wideband) band-notch antenna with a steep stop band and relates to a UWB band-notch antenna. The UWB band-notch antenna comprises a dielectric substrate (105), a radiating element (101), a square etching fractal structure (106), an impedance matching input microstrip line (102) and a cross type EBG (Electromagnetic Band Gap) structure (103) which are arranged on the dielectric substrate, and a metal ground plate (104) which is arranged under the dielectric substrate. According to the UWB band-notch antenna, the pass band width, which conforms to UWB requirements, is implemented through the radiating element, the impedance matching input microstrip line and the metal ground plate, and the steep stop band is formed by utilizing the cross type EBG structure (103) and the square etching fractal structure on the radiating element. The stop band of the antenna related by the invention is close to 6.8 Ghz, so that the mutual interference with an RFID (Radio Frequency Identification Device) system (6.8 Ghz) is avoided.

The invention discloses a novel attenuation band steep UWB (Ultra Wide Band) band-notch antenna, and relates to an UWB band-notch antenna. The novel attenuation band steep UWB band-notch antenna is formed by a dielectric substrate (105), a radiation unit (101) on the dielectric substrate, a Sierpinski triangular fractal structure (106), an impedance matching input micro-strip line (102), a cross-shaped EBG (Electromagnetic Band Gap) structure (103) and a metal grounding plate (104) under the dielectric substrate. According to the novel attenuation band steep UWB band-notch antenna disclosed by the invention, passband width required by UWB can be realized by utilizing the radiation unit, the impedance matching input micro-strip line and the metal grounding plate, and a steep attenuation band is formed by utilizing the cross-shaped EBG structure (103) and the Sierpinski triangular fractal structure on the radiation unit; the frequency of an antenna attenuation band is about 6.8Ghz, and the mutual interference with an RFID (Radio Frequency Identification device) system (the frequency is 6.8Ghz) is avoided.

The present invention discloses an antenna for ultra-wideband (UWB) communication having a band-stop characteristic. According to an embodiment of the present invention, the UWB antenna is a patch antenna employing microstrip feeding. In order to expand a bandwidth at a low frequency band, a stub is formed in a radiating element. Furthermore, since steps are formed in a ground plane, an antenna characteristic at an intermediate frequency band can be improved and a UWB characteristic can be obtained. According to another embodiment of the present invention, the UWB antenna is a patch antenna employing microstrip feeding and has a recess formed in the ground plane, thereby implementing the UWB characteristic. The antenna of the present invention has an inverse U-shaped slot formed in the radiating element, thus implementing the band-stop characteristic at the UNII band. In addition, the antenna of the present invention has includes a ground plane having a small area and has omnidirectional radiating patterns accordingly.

The present invention relates to an EBG (electromagnetic band gap)-based miniaturized dual band-notched UWB (ultra-wideband) antenna and belongs to the wireless communication technical field. The antenna of the invention comprises a dielectric plate, an ultra-wideband antenna, a longitudinal double-fork-shaped electromagnetic band gap structural array and a transverse double-fork-shaped electromagnetic band gap structural array, wherein the ultra-wideband antenna includes radiating units and a microstrip feeder line, is formed in a coplanar manner and is printed at the front surface of the dielectric plate, and the longitudinal double-fork-shaped electromagnetic band gap structural array and the transverse double-fork-shaped electromagnetic band gap structural array are printed at the back surface of the dielectric plate, are perpendicular to each other, and can play a role of wave trapping. The dual band-notched ultra-wideband antenna provided by the invention has the advantages of simple structure, compact size, low cost and excellent ultra-wideband and wave trapping characteristics, and can effectively suppress the interference of multi-frequency band electromagnetic signals and is suitable for compact and portable ultra-wideband terminal equipment.

The present invention provides an ultra wideband differential antenna with a band-notched characteristic. The ultra wideband differential antenna includes a dielectric substrate, a grounding plate located at the lower surface of the dielectric substrate, and a feeding layer located at the upper surface of the dielectric substrate; the feeding layer comprises two radiation units which are in bilateral symmetry; each radiation unit includes a microstrip feeder line and a radiation patch, wherein the microstrip feeder line is connected with the radiation patch; the grounding plate comprises four cut corners which are located at the edge of the grounding plate and are radially symmetric, a circular slot located at the middle of the grounding plate, and two C-shaped metal strips disposed in the circular slot and are in bilateral symmetry; the C-shaped metal strips are parallel to the edge of the circular slot; and gaps are left between the C-shaped metal strips and the edge of the circular slot. The ultra wideband differential antenna with the band-notched characteristic of the invention is miniaturized and achieves a band-notched function; the radiation characteristic of the antenna in high frequency bands is optimized and improved; and the gain of the antenna in the high frequency bands is also improved.

The invention provides a UWB (ultra wide band) band-notch antenna with a steep stop band, and relates to a UWB band-notch antenna. The antenna is composed of a dielectric substrate (105), a radiating element (101) arranged on the dielectric substrate, a square etching fractal structure (106), an impedance matching input microstrip line (102), a fold line type EBG (Electromagnetic Band Gap) structure (103) and a metal grounding plate (104) below the dielectric substrate. The UWB band-notch antenna with the steep stop band disclosed by the invention realizes the bandpass width required by UWB by using the radiating element, the impedance matching input microstrip line and the metal grounding plate, and forms the steep stop band by using the fold line type EBG structure and the square etching fractal structure on the radiating element. The antenna stop band that the invention relates to is near 5.2 GHz, which avoids the mutual interference with a WLAN (Wireless Local Area Network) system (5.15-5.35 GHz).

The invention discloses an ultra wideband band-notch antenna based on a crossed type EBG (Electromagnetic Band Gap) structure, relating to an ultra wideband band-notch antenna. The antenna comprises a dielectric substrate (105), a radiating element (101), an impedance matching input microstrip line (102) and a crossed type EBG structure which are arranged on the dielectric substrate, and a metal earthing plate (104) arranged under the dielectric substrate. The ultra wideband band-notch antenna realizes passband width required by UWB (ultra wideband) by using the radiating element, the impedance matching input microstrip line and the metal earthing plate, and realizes band stop characteristic by using the crossed type EBG electromagnetic band gap structure. According to the ultra wideband band-notch antenna disclosed by the invention, a stop band is near 6.8Ghz, and the mutual interference with an RFID (Radio Frequency Identification) system is avoided.

The invention discloses a flexible wearable ultra-wideband monopole antenna with band notch characteristic, which includes a grounding plate, a dielectric substrate, a feed network, and a radiation patch. The relative dielectric constant of the dielectric substrate is 2.3-3, the loss tangent value is 0.001, and the thickness of the dielectric substrate is 0.6-1mm. The grounding plate is arranged on one side of the dielectric substrate. The feed network and the radiation patch are arranged on the other side of the dielectric substrate. The radiation patch is composed of a semicircular structureand an inverted trapezoidal structure. A split-ring resonator is formed on the radiation patch through etching. The split-ring resonator is provided with an opening on the bottom side. The length andwidth of the split-ring resonator are respectively 5-9mm and 4-8mm, and the size of the opening is 2.5-3.5mm. The grounding plate is of the same width as the dielectric substrate, and is provided with a rectangular groove. The impedance bandwidth of the antenna is 2.7-12.3GHz. The antenna produces band notch characteristic in the frequency band of 5.1-5.9GHz. Except the frequency band, the antenna covers the working frequency band of an ultra-wideband communication system. By producing band notch characteristic in the frequency band of 5.1-5.9GHz, the interference of a narrowband system of WLAN with the ultra-wideband system is inhibited.

The invention discloses a variable-frequency narrow-band interference suppression method for short-wave full-band receiving. The method comprises steps of dividing an input signal into two paths, respectively employing a full-band direct collection receiving branch and a broadband variable-frequency receiving branch to receive and process the two paths of input signals, and inputting the processing results of the two branches into an FPGA for fusion output; according to the invention, the tunable narrow-band notch of the short-wave full-band is realized through a method of combining the adjustable notch technology and the narrow-band notch technology, so that the suppression of interference signals is realized, and the filter has the characteristics of tunable notch frequency in the short-wave full-band range, small notch bandwidth and large notch depth, and is easy to realize; receiving performance of an interference signal close to a channel signal is guaranteed through narrowband crystal notch, the crystal notch filter with fixed frequency can notch a short-wave interference signal with any frequency through cooperation with a frequency mixing link, and narrowband notch suppression of the interference signal is achieved through data fusion in an FPGA; and good receiving of full-band short-wave signals except interference signals is ensured.

The invention relates to a double stop-band triangular ultra wideband patch antenna based on a phase step resonator. The double stop-band triangular ultra wideband patch antenna based on the phase step resonator comprises a patch antenna 1 (comprising a regular triangular radiation unit and a feeder line), a dielectric substrate 2, a 3.5 GHz phase step resonator 3, a 5.6 GHz phase step resonator 4 and a grounding plate 5; the double stop-band triangular ultra wideband patch antenna is characterized in that resonation structures are arranged on the two sides of the feeder line of the antenna to realize the double band-notched function; the radiation unit of the antenna is of a regular triangular patch structure, and the grounding plate is partially tailored. The double stop-band triangular ultra wideband patch antenna realizes the ultra wideband transmission characteristic ( VSWRand lt; 2) from 3.1 GHz to 10.6 GHz, and respectively forms stop bands in the two narrow bands of 3.4 GHz - 3.7 GHz (WLAN frequency band) and 5.4 GHz - 6.0 GHz (WiMAX frequency band), so that the interference between the two frequency bands is effectively reduced.

A photonic microwave down-conversion system and method. The oscillation loop includes an electro-optic modulator, optical narrow-band notch filter, photodetector and electrical combiner which has the function of generating the local oscillator signal. The frequency of the local oscillator signal can be flexibly adjusted by changing the lightwave frequency output from the wavelength tunable laser. The phase modulation function of the electro-optic modulator enables no RF signal output from the down-conversion photodetector It can not only down convert the RF signals with different frequencies to the intermediate frequency signals with the same frequency, but also can down convert the RF signals with the same frequency to the intermediate frequency signals with different frequencies. This can effectively overcome the limitations of complicated structure, poor RF isolation and difficulty in flexible tuning for microwave down-conversion system in the prior arts.

The invention discloses an in-band notch broadband antenna applied to a wireless local area network (WLAN) frequency band. The in-band notch broadband antenna comprises a dielectric substrate; a radiation patch arranged on the upper surface of the dielectric substrate; a microstrip feeder line arranged on the upper surface of the dielectric substrate and connected with the radiation patch; and a metal grounding plate arranged on the lower surface of the dielectric substrate, wherein a first groove is formed in the radiation patch, two axisymmetric radiation branches are arranged in the first groove, the two radiation branches are not contacted, each radiation branch comprises a first branch and a second branch perpendicular to the first branch, one end of the first branch is connected with the radiation patch, the other endof the first branch is connected with the second branch, a second groove is etched in the metal grounding plate, and the position of the second groove corresponds to the microstrip feeder line. According to the invention, the peak value of VSWR is regulated and controlled by adjusting the distance d from the bottom edge of the first groove to the feed port, and the peak value position of the VSWR is regulated and controlled by adjusting the distance g between the two radiation branches.

The invention discloses a light-control reconfigurable ultra-wide-band notch antenna used for cognitive radio. The light-control reconfigurable ultra-wide-band notch antenna comprises an antenna radiation unit, a coplanar waveguide feeder line, an FR4 medium dielectric substrate, a symmetric trapezoidal floor, a first light-control silicon switch, a second light-control silicon switch, a third light-control silicon switch, a fourth light-control silicon switch and a fifth light-control silicon switch, the antenna radiation unit, the coplanar waveguide feeder line, the symmetric trapezoidal floor, the first light-control silicon switch, the second light-control silicon switch, the third light-control silicon switch, the fourth light-control silicon switch and the fifth light-control silicon switch are positioned on a same side of the FR4 dielectric substrate, and the coplanar waveguide feeder line is positioned in the middle of the symmetric trapezoidal floor; the antenna radiation unit comprises a U-shaped monopole antenna which is connected with the coplanar waveguide feeder line, a bent symmetric groove is formed in a U-shaped surface-mount-device monopole and is symmetric according to the coplanar waveguide feeder line in shape. The light-control reconfigurable ultra-wide-band notch antenna has the advantages of small size, high omnidirectivity, wide frequency band, small switch electromagnetic interference and the like and is suitable for the field of cognitive radio.