37results about How to "Suppression of higher order modes" patented technology

A multimode occulting antenna with a stable phase center comprises a reflection cavity, a lower radiation paster, an upper radiation paster, four feed probe sleeves, four feed probe inner cores and two support columns. Each feed probe sleeve comprises a metal seat and filler, one end of the metal seat is a metal column, the other end of the metal seat is a cylindrical metal cavity, and the filler is used for filling the cylindrical cavity of the metal seat. The sleeve-shaped probes are coupled with feed through four points, probes are uniformly distributed on the circumference, an aerial radiation paster consists of an upper layer and a lower layer, the lower layer is coupled with the feed through the sleeve-shaped probes, the upper layer is coupled with the feed through the lower radiation paster, the middle is supported by the metal support columns, and the reflection cavity is of a round bowl-shaped structure and higher than the upper radiation paster. The occulting antenna is excellent in performance and structure, simple and reliable in process, wide in frequency band, capable of meeting use requirements of a GPS (global positioning system), BD-2, GALILEO and GLONASS, wide in beam coverage, high in gain, stable in phase center, excellent in axial ratio performance, and applicable to a precise obscuration detection system and other high-precision detection systems.

Broadband filter antenna, includes five layers from top to bottom, The first layer structure comprises a top layer patch structure, the second layer structure comprises a bottom layer patch structure,the third layer structure comprises two folding resonators, the fourth layer structure comprises a large metal formation with a pair of vias, and the fifth layer structure comprises a feeding structure. The invention solves the problem of large plane size and realizes the filtering performance of the antenna. Three reflective zeros are generated by stacked multi-patch resonator to widen the bandwidth of the antenna. The odd mode of the resonator produces the low-end radiation zero, and the coupling between the top and bottom patch structures produces the high-end radiation zero, so as to improve the frequency selectivity of both sides of the working band. By adjusting the impedance ratio of the first part and the second part of the folding resonator, the low-end radiation zero can be adjusted while maintaining the bandwidth. The out-of-band mode is suppressed by using the short-circuit branch loaded on the feeder to improve the out-of-band suppression at the high end of the antenna frequency.

The invention discloses a tri-band integrated antenna. The antenna consists of two parts, namely an L/S radiating unit and an ultra-high frequency (UHF) radiating unit, wherein the L/S radiating unit comprises a plurality of metal sleeve feed probes, an L/S feed network, an upper radiating piece, a lower radiating piece and a reflection chamber; the UHF radiating unit comprises a plurality of spiral lines, a supporting sleeve, a feed connecting part, an UHF feed network and a base; the spiral lines are wound on the supporting sleeve; the bottom ends of the spiral lines are connected with the output port of the UHF feed network through the feed connecting part; and the UHF feed network is arranged in the base. The antenna provided by the invention has high phase centre stability, a compact structure and a small size, and can cover UHF, an L-band and an S-band, and meet the requirements of spaceborne or airborne.

The invention discloses a large mode field diameter and negative refractive index single mode glass fiber. The glass fiber comprises a fiber core, an inner cladding and an outer cladding; the refractive index of the fiber core is N1, the refractive indexes of the inner cladding and the outer cladding are respectively N2 and N3, which satisfy the relation: N2 is more than or equal to N1 and N2> N3; the lumination ion is mixed into the fiber core, which is the lanthanum ion or the combination of one or several transition metal ions; the mixing concentration is more than 1*1019 ions/cm3. The glass fiber of the invention forms the wave guiding structure between the fiber core and the inner cladding under the common function of the plus refractive index and the wave guiding refractive index; the laser oscillates stably in the fiber core. The invention realizes the large mode field diameter single mode laser output in the fiber.

The invention relates to an L-band four-ridge ortho-mode transducer. The ortho-mode transducer is a modified index gradually-changing curve loaded with ridge diaphragms and a coaxial excitation structure, the operating frequency is 1-2GHz, and the ortho-mode transducer is applied to a radio telescope L-band receiver system. The ortho-mode transducer is composed of a circular waveguide, a four-ridge waveguide gradually-changing transformation segment, a four-ridge circular waveguide, ridge diaphragms, a short-circuit back cavity, a first coaxial probe and a second coaxial probe, and is characterized in that the diameter of the circular waveguide is designed according to the lowest operating frequency; the four-ridge waveguide gradually-changing transformation segment selects a modified index gradually-changing type impedance transformation mode so as to ensure transmission from a dominant mode of the four-ridge circular waveguide dominant mode to a dominant mode of the circular waveguide; chamfer modification is performed on the four-ridge cross section inside the four-ridge circular waveguide so as to ensure that a phenomenon of mutual interference between the ridge diaphragms does not occur; and a four-ridge waveguide coaxial transformer adopts a coaxial feed mode, and the short-circuit back cavity thereof selects a conical design. Measurement and simulation results of the ortho-mode transducer in reflection loss and isolation are basically identical, and radio astronomical observation requirements can be met.

The invention discloses a phase shifting unit and an MEMS (micro-electromechanical system) terahertz phase shifter composed of the same, which mainly solve the problems that the existing terahertz phase shifter is overmany in parasitic parameters, strong in process sensitivity, overlarge in driving voltage and the like. The phase shifting unit comprises a substrate, CPW signal line ground wires, grooves, CPW signal lines, an MEMS movable beam and a CPW signal line, wherein the CPW signal line ground wires are arranged at two opposite sides of the substrate, the grooves are arranged at the opposite ends of the CPW signal line ground wires, the CPW signal lines are inserted into the CPW signal line ground wires through the grooves and are provided with open circuit terminals, the two ends of the MEMS movable beam are respectively connected with the CPW signal lines provided with the open circuit terminals, the CPW signal line is arranged on the substrate and is positioned below the MEMS movable beam, one CPW signal line ground wire is provided with a slot communicated with the groove on the CPW signal line ground wire along the length direction of the CPW signal line ground wire, an electrostatic drive offset line is arranged in the slot, one end of the electrostatic drive offset line is connected with the CPW signal lines provided with the open circuit terminals, the other end of the electrostatic drive offset line is connected with an offset electrode positive pole bonding pad, and the CPW signal line and the CPW signal lines provided with the open circuit terminals share the CPW signal line ground wires.

The invention discloses a metal diaphragm slotting loading circular waveguide circular polarizer, and the polarizer comprises a metal diaphragm and a circular waveguide. A metal diaphragm slot is formed in the outer side of the circular waveguide; the metal diaphragm is a stepped metal diaphragm, and the metal diaphragm is inserted into the metal diaphragm slot. According to the invention, the phase difference of the circular polarizer in a wide frequency band can be kept near 90 degrees; the circular waveguide is slotted and loaded with the metal diaphragm, so a high-order mode can be greatlyinhibited, and high-order resonance is avoided; phase adjustment is achieved by adjusting the depth of the metal diaphragm inserted into the circular waveguide, adjustability is good, the structure is simple, the requirement for machining precision is lowered, and machining batch production is easy.

The invention discloses a high-isolation large-scale array synthesis power amplifier, which comprises a base and a waveguide cavity formed by the base, wherein multiple stacked cards are arranged in the waveguide cavity; each card comprises an antenna circuit board and at least one amplifier chip arranged on the antenna circuit board; at least one antenna is arranged on the antenna circuit board;the input end and the output end of each amplifier chip are connected with the input end and the output end of one antenna, and an amplification channel is formed; and each amplification channel is arranged in an isolation cavity arranged in the waveguide cavity. The synthesis space can be saved; in a condition of realizing large-scale array synthesis, the overall space of the synthesis power amplifier can be greatly reduced, coupling among the amplifier chips is reduced, high isolation between amplification channels is realized, a high order mode in the cavity is suppressed, the working bandwidth is expanded, and the high-isolation large-scale array synthesis power amplifier can be widely applied to a synthesis amplifier industry.

The invention discloses a 77GHz power monitoring circuit based on a detector. The 77GHz power monitoring circuit comprises a W-band standard waveguide, a waveguide microstrip fin line transition structure, a 50-ohm microstrip line, a parallel coupler, an MMIC attenuator chip, a 50-ohm thin-film resistor, a detector circuit and an operational amplifier circuit. The P1 port and the P2 port of the parallel coupler can be respectively used as input and output or output and input, so that a signal transmission channel during normal work is provided; and the other small part of signals are simultaneously transmitted to a P3 port of the parallel coupler and are sent to a detector circuit to realize power monitoring. The circuit can be cascaded at the input end of a receiver to form a receiver real-time protection circuit and can also be cascaded at the output end of a transmitter to form a transmitter power real-time monitoring circuit, normal work of a transceiving front end is not affected, and performance deterioration of the receiver and the transmitter is avoided.

A duplex communication module of an integrated waveguide isolator comprises a cavity and a cover plate, a concave common channel is formed in the center line of the cavity, a transmitting channel is formed in one side of the common channel, a receiving channel is formed in the other side of the common channel, and the transmitting channel and the receiving channel are both formed in the cavity. The input end of the common channel is communicated with the output end of the transmitting channel, the output end of the common channel is communicated with the input end of the receiving channel, anda transmitting end isolator, a transmitting end low pass and a transmitting end filtering channel which are used for forming a microwave transmitting path are arranged in the transmitting channel. Areceiving end isolator for forming a microwave receiving path, a receiving end low pass and a receiving end filtering channel are arranged in the receiving channel. According to the invention, the isolator and the low-pass filter are arranged in the cavity of the duplexer, so the matching precision between the isolator and the filter can be effectively improved, and the performance loss of the system is reduced.