402 results about "Microwave band" patented technology

A magnetic head apparatus is provided which is capable of recording data in a recoding layer having high coercive force with high accuracy without heating. A magnetic recording and reproducing apparatus is also provided which has the magnetic head apparatus. A recording head has: a main magnetic pole; a recording-side front-end shield (a return magnetic pole); a recording-side rear-end shield (a return magnetic pole); a main coil for generating a perpendicular recording magnetic field at the main magnetic pole; and an auxiliary coil for generating a longitudinal alternating current magnetic field having a frequency in the microwave band at the main magnetic pole.

A small radio frequency IC tag which can obtain sufficiently long communication distance with radio wave in the microwave band even if an antenna is made small and the radio frequency IC tag is embedded in metal material. An O-shaped antenna is formed to narrow the width of a neck part in which an IC chip is mounted and widen the width of radiating electrodes constituting radiating part of radio wave. The radiating electrodes are formed into offset structure on right and left sides of the feeding point so that areas of right and left radiating parts of the feeding point in which the IC chip is mounted are unsymmetrical. Further, a ground electrode is provided so that a dielectric body is held between the radiating electrodes and the ground electrode and the radiating electrode is connected to the ground electrode at the side of the dielectric body.

An electromagnetic noise suppressor of the present invention has magnetic resonance frequency of 8 GHz or higher, and the imaginary part μ″_H of complex magnetic permeability at 8 GHz is higher than the imaginary part μ″_L of complex magnetic permeability at 5 GHz. Such an electromagnetic noise suppressor is capable of achieving sufficient electromagnetic noise suppressing effect over the entire sub-microwave band. The electromagnetic noise suppressor can be manufactured by forming a composite layer 3 on the surface of a binding agent 2 through physical deposition of a magnetic material on the binding agent 2. The structure with an electromagnetic noise suppressing function of the present invention is a printed wiring board, a semiconductor integrated circuit or the like that is covered with the electromagnetic noise suppressor on at least a part of the surface of the structure.

The invention discloses a substrate integrated waveguide split ring resonator-based microwave band pass filter. The microwave band pass filter comprises a substrate integrated waveguide which is formed by fixing two rows of metal members on a dielectric substrate, wherein the two ends of the substrate integrated waveguide are connected with a micro-strip feed line respectively; the surfaces of both the micro-strip feed line and the substrate integrated waveguide are made of metal dielectric; the upper surface of the substrate integrated waveguide is positioned between the two rows of metal members to corrode an m*n split ring resonator array; and a row of dumbbell-shaped area bodies or dumbbell-shaped deformation areas are corroded corresponding to each line of split ring resonators on the lower surface of the substrate integrated waveguide between the two rows of metal members. The band pass filter has the advantages of out-of-band steep attenuation, small volume, light weight and high power capacity and is easy to be integrated with other planar microwave and millimeter-wave circuits, so that the band pass filter is expected to be applied to the microwave and millimeter-wave integrated circuit or a millimeter wave integrated circuit.

The invention discloses a terahertz inverse synthetic aperture radar imaging method based on a frequency modulation step frequency to solve the problem that in the prior art, the range resolution and the direction resolution of inverse synthetic aperture radar imaging in the microwave band are not high. The method includes the steps of firstly, obtaining a terahertz pulse echo signal; secondly, conducting pulse compression; thirdly, synthesizing a broadband; fourthly, conducting windowing and correcting; fifthly, conducting distance Doppler imaging; sixthly, obtaining an imaged picture. According to the method, the characteristic that the terahertz wave has the high frequency and the broadband is combined with the frequency modulation step frequency system so that the high-resolution terahertz inverse synthetic aperture radar imaging can be achieved through the method of synthesizing the broadband.

The present invention is a microwave generating apparatus comprising: a switch signal generator that generates a square wave switch signal having a fundamental frequency of a microwave band; a switching power amplifier that performs a switching power amplification based on the switch signal so as to output an amplified signal; a variable voltage supplier that is capable of variably supplying a driving voltage for amplification to the switching power amplifier; a microwave selector that extracts from the amplified signal a sine wave signal of the same frequency as the fundamental frequency of the switch signal so as to output the same as a microwave; an output signal detector that detects the microwave; and a driving voltage controller that controls the variable voltage supplier based on a result detected by the output signal detector.

The invention discloses an optoelectronic oscillator based on intermediate frequency selection. The optoelectronic oscillator comprises a local oscillator signal source, a microwave power divider, a laser, a polarization maintaining fiber, a single-mode fiber, an electro-optic modulator, a photoelectric detector, a microwave band-pass filter, a frequency mixer, an intermediate frequency band-pass filter and an intermediate frequency amplifier. Through up-conversion and down-conversion, side mode suppression of an OEO is realized through a narrowband intermediate frequency band-pass filter, so that an OEO loop is allowed to be longer to realize high Q value; and through matching of the polarization maintaining fiber in corresponding length and group delay of the intermediate frequency band-pass filter, influence of phase noise of a local oscillator signal is eliminated. The up-conversion in an OEO structure is realized through a microwave photon link; advantages of wide bandwidth and small insertion loss are realized; and frequency conversion loss can be reduced obviously by improving laser power.

A MnAl alloy magnetic absorbing material provided by the invention comprises atoms in the following percentage: 37-72% of Mn and 28-63% of Al. The absorbing material is prepared by a method comprising the following steps: melting raw materials of metal Mn and Al with purity no less than 99.50% under protection of argon; carrying out uniformization treatment on cast ingots at 900-1100 DEG C in vacuum or under protection of argon; milling the cast ingots; and carrying out tempering heat treatment at 200-600 DEG C. The MnAl alloy magnetic absorbing material has characteristics of small density, good microwave absorption characteristics in microwave band of 2-18 GHz, wide frequency band of absorption, good oxidation resistance, corrosion resistance and temperature stability, does not contain strategic metal elements like Co, Ni and rare earths, simple preparation technology, abundant raw materials and low price. Among the magnetic absorbing materials, the MnAl alloy magnetic absorbing material provided by the invention is more suitable for preparation of microwave absorption products with wide frequency band of absorption, high absorbing efficiency, small material density, good oxidation resistance, corrosion resistance and temperature stability, and low cost.

A high-frequency imaging system for the millimeter and submillimeter radiation includes a high frequency lens to image an object at its focal plane. The object emits electromagnetic radiation at a first frequency above the microwave band of the electromagnetic spectrum. A local oscillator generates an electromagnetic beam at a second frequency to illuminate a plurality of dual-frequency antennas at the focal plane of the lens. Intermodulation of first and second frequencies generates a signal distribution of a third frequency over the focal plane, which represents an image. Also, a method of providing an image at the third frequency of an object emitting electromagnetic radiation at a first frequency is provided. The method includes imaging the electromagnetic radiation at the first frequency from each point of the object onto the focal plane. An electromagnetic beam is transmitted to illuminate all elements of the focal plane array.

The present invention provides an SSPPs type microwave band-pass filter, and relates to the microwave filter technology field. The filter adopts a three-segment type structure, the first segment is a coplanar waveguide segment, the second segment is a transition segment transformed from the coplanar waveguide segment to an SSPPs segment, and the third segment is the SSPPs segment, wherein the SSPPs segment adopts a novel child-mother composite groove structure characterized by arranging the child groove structures which are periodic, are in mirror symmetry and are arranged parallelly in the mother grooves. By the number and the geometric sizes of the child grooves, the sub-wavelength bound effect of a microwave electric field can be improved further, and the band-notched characteristic of the SSPPs filter is more excellent. The filter can be widely used in the microwave communication systems, such as the micro-strip circuits of L-wave band to X-wave band, a microwave base station, etc.

The invention discloses a wideband low sidelobe lens antenna based on novel artificial electromagnetic material. The antenna comprises a lens body with an axis in a same straight line, an impedance matching layer, and a feed source. A refractive index of the lens body shows gradient distribution along a radial direction, and a refractive index of the impedance matching layer shows uniform distribution along s axial direction. The lens body and the impedance matching layer are made from the novel artificial electromagnetic material. The new artificial electromagnetic material consists of basic units of periodic arrangements. In the invention, the wideband low sidelobe lens antenna based on the novel artificial electromagnetic material realizes, for a first time, simultaneously regulating an aperture field amplitude and phase distribution in a microwave band; a bandwidth of the lens antenna is quite wide; dispersion in a Ku band is not clear, and the performance is stable; the production is simple; the technology is mature; the price is not high; the promotion is easy; and structural parameters can be scaled to be suitable for different wave bands such as the microwave, millimeter wave and terahertz wave.

The invention discloses an adjustable microwave band-pass filter. A microwave circuit substrate is provided with a double-resonance modal annular resonator and a corresponding input coupling unit, an output coupling unit and a disturbance unit, wherein an even number of micro mechanical bridge films are placed on the resonator in a mirror symmetry mode to adjust a center frequency; and one or more micro mechanical bridge films are placed on the disturbance unit to adjust the bandwidth. The filter uses a variable capacitance effect generated by a capacitance loading structure of the micro machined bridge films to load a dual-mode resonator and a disturbance structure thereof, so that the adjustment of filtering characteristics, such as the passband center frequency, the passband bandwidth and the like can be realized by fewer micro mechanical bridge films and less chip area occupation. Compared with the prior dual-mode filter and the micro mechanical adjustable band-pass filter, the adjustable microwave band-pass filter has the advantages of more flexible structure, lower technology complexity and better device overall performance, and is suitable for filtering devices based on planar transmission lines and on-chip waveguide at the same time.

The invention discloses an SIW-based dual-frequency slot array antenna. The SIW-based dual-frequency slot array antenna comprises a dual-layer dielectric substrate, wherein a printed metal feeder is arranged on an upper surface of an upper-layer dielectric plate, a feeding slot, a low-frequency radiation slot and a high-frequency radiation slot are etched on an upper surface of a lower-layer dielectric substrate after copper coating, a lower surface is coated with copper, metal via holes are processed in four edges of the lower-layer dielectric plate, the two layers of dielectric plates are assembled and overlapped, the lower-layer dielectric substrate and metal on the upper surface and the lower surface thereof can form an SIW cavity, energy enters the SIW cavity at a lower layer from theprinted metal feeder at an upper layer via the feeding slot, a TE20 mode is formed, radiation of different frequency bands is achieved, low-frequency radiation arrays are arranged at two sides of a central axis of the antenna, a high-frequency radiation array is arranged on the central axis, and the design of the dual-frequency antenna and a relatively good directional diagram radiation effect are achieved. The SIW-based dual-frequency slot array antenna can be simultaneously applied to a microwave band and a millimeter wave band, is high in gain, wide in bandwidth, small in loss and low in profile and is easy to process.

The invention discloses a wideband vector network analyzer. The wideband vector network analyzer is characterized by adopting a frequency slicing method and divides a test frequency range into three frequency bands, namely a low frequency band, a radio frequency band and a microwave band, and an excitation signal generation method, a test signal directional separation method and a frequency conversion receiving method of each frequency band are different. The wideband vector network analyzer is composed of a network analysis module, a 6GHz-20GHz front-end module and a 6G front-end module on the whole, wherein the network analysis module comprises an excitation signal source submodule, a fixed local oscillator module, a local oscillator signal source submodule and a medium frequency processing submodule, the 6GHz-20GHz front-end module and the 6G front-end module are connected, share a 6-20G front-end module test port, and are respectively connected to the network analysis module, and therefore the interaction among the 6GHz-20GHz front-end module, the 6G front-end module and submodules of the network analysis module is achieved. The wideband vector network analyzer adopt the measuring frequency slicing method, enables the processing of different frequency bands to be mutually independent, effectively avoids the difficulties in the design of low-frequency measurement and high-frequency measurement on the condition of small size, and achieves a wider frequency measurement range.

An MMIC (Microwave Monolithic Integrated Circuit)-mounted substrate includes a double-metal-foil dielectric substrate having a dielectric substrate with a metal foil pattern formed on both sides of the substrate, an MMIC that is a surface-mount high power amplifier mounted on one side of the double-metal-foil dielectric substrate, and a metal chassis attached to the other side of the double-metal-foil dielectric substrate. The double-metal-foil dielectric substrate has a plurality of through holes. A copper foil pattern that is a metal foil pattern continuously extends to cover the inner surfaces of the through holes and both sides of the dielectric substrate, and solder is buried in the through holes.