77 results about "Microstrip patch antenna" patented technology

The invention discloses a broadband high-gain microstrip antenna, which is provided with a rectangular radiation patch, a symmetrical grooving parasitic patch, a dielectric substrate, a metal bottom plate and a polytetrafluoroethylene support column, the rectangular radiation patch and the symmetrical grooving parasitic microstrip are attached to the upper layer of the dielectric substrate; a certain distance is formed between the rectangular radiation patch and the slotted parasitic patch and is used for coupling electromagnetic waves; the upper dielectric substrate is provided with two through holes for feeding; the metal bottom plate and the upper-layer substrate are fixed through four polytetrafluoroethylene supporting columns; a space is reserved in the middle to form an air substrate; and an SMA interface is arranged below the floor. According to the microstrip patch antenna, the forms of differential feeding and parasitic patch adding are adopted, the high gain and broadband characteristics of the microstrip patch antenna are achieved, the profile of the antenna is kept within 0.1 lambda, and the unipolar radiation pattern is achieved while high performance is guaranteed. In addition, the antenna is relatively simple in technical structure and convenient for later processing, can be used as an array unit for arraying, and meets the requirements of modern communication.

The invention relates to a microstrip patch antenna based on an antipodal double-helix groove, which comprises the antipodal double-helix groove, a patch, a substrate, a grounding plate and a coaxial probe, and is characterized in that the substrate is mounted on the grounding plate, the patch is mounted on the substrate, the antipodal double-helix groove is formed in the patch, and the coaxial probe sequentially penetrates through the grounding plate, the substrate and the patch; the coaxial probe is used for feeding the patch, and a radio frequency electromagnetic field is generated between the patch and the grounding plate. According to the microstrip patch antenna, the antipodal double-spiral grooves are formed, the path length of current flowing through the patch is increased, the resonant frequency of the antenna is reduced to a large extent, meanwhile, the good radiation characteristic is kept, the antenna radiation efficiency is high, the directional diagram is regular, and the electrical size of the microstrip patch antenna is reduced while the high radiation efficiency is kept.

Embodiments herein disclose an antenna system comprising a plurality of panel comprising at least one Multiple Input Multiple Output (MIMO) antenna array, including a plurality of microstrip patch antenna elements and stacked patch antenna elements. The microstrip patch antenna elements, configured in a linear array, facilitate a lower operating frequency, while the stacked patch antenna elements, placed atop the microstrip patch antenna elements, achieve a higher operating frequency. The stacked patch antenna elements are connected in series and oriented at a predefined angle of 90° relative to the microstrip patch antenna elements. A panel from the plurality of panels is arranged at a pre-defined angle of 90° relative to an adjacent panel from the plurality of panels for polarization diversity to obtain the multifunctional shared aperture 8N-port MIMO antenna system.

The application discloses a dual-polarized microstrip patch antenna applied to a millimeter wave phased array, and belongs to the field of radio frequency front ends.The antenna mainly comprises two substrates and two patch structures, wherein the top patch is fed by two coaxial probes, the feeding port has two feeding slits, and the bottom patch is in a cross shape, which increases the cross-polarization ratio of the dual-polarized antenna radiation.The antenna realizes the dual-polarized characteristic at H plane + / -45 DEG, the 10dB relative bandwidth is 38.9%, and the radiation pattern half-power beam width is greater than 100 DEG. The antenna has the characteristics of simple structure and simple manufacturing, and can be rapidly printed and manufactured by adopting a planar microstrip structure.

An antenna-based system for hyperthermia treatment of breast cancer, consisting of: a G-shaped microstrip patch antenna configured for operation at an ISM frequency of 434 MHz and having dimensions of 3.6 cm × 3.8 cm × 1.6 cm; an aluminum cavity chamber to accommodate the G-shaped microstrip patch antenna; a coaxial feed line configured to allow an impedance matching of 50 ohms to the G-shaped microstrip patch antenna; a bolus of deionized water configured to surround the aluminum cavity chamber, wherein the bolus of deionized water is further configured to serve as a cooling medium for controlling the skin surface temperature, and wherein the bolus of deionized water is further configured to reduce hotspots and improve the radiation efficiency of the G-shaped microstrip patch antenna; and A polyethylene film was positioned between the G-shaped microstrip patch antenna and the bolus of deionized water to prevent interference between the G-shaped microstrip patch antenna and a breast tissue phantom.

The invention provides a multi-frequency-point low-power-consumption ultra-wideband radio frequency array near-field non-contact detection method and system, and relates to the technical field of ultra-wideband near-field detection, and the system comprises an MIMO array system which comprises an ultra-wideband signal transmitting module, an ultra-wideband signal receiving module, a transmit-receive conversion control module and an MIMO array. A plurality of symmetrical transmitting and receiving units of the MIMO array share the same MIMO physical array, wherein each array unit adopts a microstrip patch antenna; information transmission is carried out through a signal interface, and the MIMO array unit sequentially transmits ultra-wideband radio frequency signals to a near-field area, synchronously and sequentially receives echo signals of a measured object and carries out multi-frequency-point sampling; the ultra-wideband radio frequency detection signal is composed of a plurality of detection pulses, and the echo signal of each detection pulse is sampled at a plurality of frequency points. According to the multi-frequency-point low-power-consumption ultra-wideband radio frequency MIMO array near-field non-contact detection method disclosed by the invention, the detection data acquisition speed is improved.

The application discloses an array antenna applied to three-dimensional multi-target arbitrary power distribution wireless energy transmission, and belongs to the field of wireless energy transmission. The array antenna comprises a transmitting antenna and a receiving antenna, and a plurality of transmitting antenna array units and a plurality of receiving antenna array units are arranged in the transmitting antenna and the receiving antenna respectively. In the transmitting antenna, the distribution of the plurality of transmitting antenna array units is divided into two layers, the transmitting antenna array units in each layer are arranged to form a circle, and an open three-dimensional space is formed. In the receiving antenna, the plurality of receiving antenna array units are distributed on two parallel planes, and the two planes are located at the center of the three-dimensional space formed by the transmitting antenna. The transmitting antenna array unit is a rectangular microstrip patch antenna. The array antenna can meet the application scene of three-dimensional multi-target arbitrary power distribution wireless power transmission.

The application discloses a library high-density book management system and a management method thereof, and belongs to the field of library management. The library high-density book management system comprises a multi-mode SAW sensing label, a reader-writer head terminal, and a regional controller. The reader-writer head terminal is arranged at the top center of each bookshelf unit at an interval of 3-5 meters. The reader-writer head terminal is composed of a small linear array of 4-8 microstrip patch antennas, generates high-frequency pulses, and receives reflected signals, and is used for accurately measuring echo arrival time and phase. The regional controller is arranged in each reading room or area, and is responsible for managing all reader-writer head terminals in the area. The regional controller is a controller with a built-in FPGA, and realizes real-time beam control and signal processing. The application realizes passive sensing of the physical state of books, and realizes high-precision positioning through a beam arrival time difference.

The application discloses a broadband low radar scattering cross section antenna loaded with an ATFSS, which comprises three layers of dielectric plates, namely, an upper layer plate, a middle layer plate and a lower layer plate, the upper surface and the lower surface of the upper layer plate are attached with wave absorbing structures, the lower surface of the middle layer plate is attached with a band-pass FSS structure, the upper surface of the lower layer plate is attached with a patch antenna, the lower surface of the lower layer plate is a metal ground plate, coaxial line feeding is adopted, and the upper layer plate, the middle layer plate and the lower layer plate are all air cavities. The broadband low radar scattering cross section antenna adopts the wave absorbing structure with a multi-resonance structure and the band-pass FSS structure, can realize the integrated characteristics of wave absorption and wave transmission, and the wave absorbing structure and the band-pass FSS can be loaded as a coating above the microstrip patch antenna to realize the RCS reduction in a wide frequency band under the condition of ensuring the normal radiation of the antenna.

The invention discloses an ice layer thickness sensor based on a dual-frequency antenna and a measuring method, belongs to the technical field of radio frequency sensing, and aims to solve the problems of small measuring range, misjudgment in a transition area and poor environmental interference resistance of a single-frequency microwave phase detection method. The sensor comprises a metal shell, a radio frequency board, a core control board, a double-frequency microstrip patch antenna, a double-frequency signal generator, a power division circuit, an amplitude-phase detector and an algorithm processing module. The dual-frequency microstrip patch antenna adopts a transmitting-receiving integrated structure, a reference signal and an incident signal are separated through a power division circuit, a dual-path phase difference is extracted through an amplitude-phase detector, and an algorithm processing module is used for solving the thickness of an ice layer based on a bilinear interpolation algorithm in combination with a thickness-phase difference two-dimensional characteristic plane. Through dual-frequency signal physical cooperation and algorithm fusion, large-range, high-precision and high-robustness ice layer thickness non-contact detection is realized, and the method is suitable for real-time monitoring of scenes such as road ice layers and the like.

The utility model discloses a microstrip patch antenna which comprises a dielectric substrate and a radiation patch. The radiation patch is arranged on the dielectric substrate, the radiation patch is E-shaped, the parallel edge of the E-shaped radiation patch is defined as a first sub-radiation patch, the vertical edge of the E-shaped radiation patch is defined as a second sub-radiation patch, and the length of the first sub-radiation patch is larger than or equal to 2.1 mm and smaller than or equal to 2.5 mm. The E-shaped structure enables the current to bypass between the first sub radiation patch and the second sub radiation patch, which is equivalent to increasing the electrical length of the radiation patch and reducing the resonant frequency of a fundamental mode, so that the low-frequency band bandwidth is broadened; the edges of the first sub-radiation patch and the second sub-radiation patch can generate strong electromagnetic field coupling to excite an additional parasitic resonance mode, so that the frequency band is further widened, and the bandwidth of the microstrip patch antenna is effectively widened. Wherein the first sub radiation patch of 2.1 mm to 2.5 mm enables the resonant frequency of the microstrip patch antenna to range from 43.7 Ghz to 55.1 Ghz, the relative bandwidth is 23%, and high bandwidth is achieved.

This invention discloses a miniaturized filtered circularly polarized microstrip patch antenna, comprising: an upper dielectric substrate and a lower dielectric substrate; a main radiating patch is printed in the middle region of the upper surface of the upper dielectric substrate; a first rectangular slot is provided on the main radiating patch; unequal-length cross-shaped patches and longitudinal rectangular parasitic patches are printed on the lower surface of the upper dielectric substrate; a short-circuit parasitic patch and a longitudinal grounded microstrip feed line are printed on the upper surface of the lower dielectric substrate; a ground plane is printed on the lower surface of the lower dielectric substrate; a second rectangular slot is formed at the upper left corner of the main radiating patch, and a protruding rectangular protrusion is provided at the upper right corner of the main radiating patch. This invention utilizes the advantages of the patch antenna's low profile and small size to achieve miniaturization, can generate three circularly polarized radiation frequencies to achieve broadband circular polarization performance, and can generate two radiation nulls to achieve bandpass filtering response.

A microstrip antenna comprises a substrate, a grounding layer located on the second side of the substrate, a first patch located on the first side of the substrate, and a second patch located on the first side of the substrate. The first patch is connected to the first port. The second patch is separate from the first patch and is connected to the second port. A plurality of short-circuit through holes connected with the grounding layer are formed in the first patch and the second patch respectively. The radiation pattern of each unit also has an RPD characteristic, which is very promising for a large-scale MIMO or array antenna.

The invention discloses a microstrip patch antenna, a UWB antenna and a vehicle, relates to the technical field of vehicle-mounted antennas, and is used for expanding the bandwidth of the microstrip patch antenna. Comprising a radiation patch unit, a parasitic patch unit, a reference ground and a feed structure, the reference ground is opposite to the radiation patch unit and the parasitic patch unit and is arranged at intervals; the feed structure is used for feeding an excitation signal into the radiation patch unit; the parasitic patch unit is located on the peripheral side of the radiation patch unit, and the parasitic patch unit and the radiation patch unit are coplanar and arranged at intervals.

The invention relates to a small broadband microwave anechoic chamber based on a non-uniform artificial surface, the small broadband microwave anechoic chamber comprises a 36-polygon cylindrical shell, a broadband artificial medium wave-absorbing unit and a transmitting antenna, the broadband artificial medium wave-absorbing unit is attached to the inner wall of the 36-polygon cylindrical shell, edges are uniformly arranged on the 36-polygon cylindrical shell at intervals along the perimeter direction of the outer side of the 36-polygon cylindrical shell, and the transmitting antenna is arranged on the outer side of the 36-polygon cylindrical shell. A transmitting antenna is attached between every two adjacent edges, and the transmitting antennas are microstrip patch antennas. The broadband artificial medium wave-absorbing unit can effectively absorb 8-12 GHz electromagnetic waves incident at 0-70 degrees, has the advantages of multiple angles, broadband and high absorptivity, and provides a high-quality low-reflection test environment for scenes such as antenna measurement and microwave imaging which have strict requirements on the electromagnetic environment; the device is small in size, compact in structure and easy to install and integrate, the used materials are common materials, large-scale expansion is easy, and the device has the advantages of being passive, easy to machine and low in cost.

The application provides a broadband wide-angle scanning microstrip antenna unit structure and an antenna array. On the basis of ensuring a low profile of the antenna, the broadband wide-angle scanning capability of the microstrip patch antenna is realized through structural design, meanwhile, space is reserved as a design area of an optical radar, and an antenna unit for integrated design of an optical / electrical radar array is realized. Technical problems that the antenna bandwidth is narrow in the prior art, and the profile, volume and weight of the antenna affect the performance of the radar are solved.

The antenna is of a layered structure and comprises a first dielectric substrate and a second dielectric substrate which are arranged in parallel, an air layer is arranged between the first dielectric substrate and the second dielectric substrate, a rectangular parasitic metal patch is arranged on the upper surface of the first dielectric substrate, and the rectangular parasitic metal patch is arranged on the lower surface of the second dielectric substrate. Each rectangular parasitic metal patch is connected with a continuously bent metal stub line; a rectangular driving metal patch is arranged on the upper surface of the second dielectric substrate, and a metal ground is arranged on the lower surface of the second dielectric substrate. The wide axial ratio bandwidth and circular polarization self-decoupling of the laminated microstrip patch antenna can be realized without an additional decoupling structure or circuit, and the antenna has the characteristics of simple structure, wide axial ratio bandwidth, self-decoupling, multi-antenna expansion, easy integration and the like, and is suitable for satellite communication, global positioning system, mobile communication and the like.

The invention discloses a high-transmittance microstrip patch antenna and a manufacturing method thereof, the high-transmittance microstrip patch antenna comprises a transparent substrate base material, one surface of the transparent substrate base material is provided with a radiation unit metal grid layer, the other surface of the transparent substrate base material is provided with a grounding plate metal grid layer, the upper surface and the lower surface of the transparent substrate base material are provided with grooves, and the upper surface and the lower surface of the transparent substrate base material are respectively provided with a metal grid layer. The groove is filled with conductive metal to form a conductive metal layer, and the radiation unit metal grid layer and the grounding plate metal grid layer are embedded into the groove; through the structure of embedding the metal grids in the grooves and the complementary topology design, while the radiation unit maintains the solid grids to guarantee the radio frequency performance, the metal shading area is reduced through the hollowing of the grounding plate, and the collaboration of the visible light wave band transmittance and the square resistance is remarkably optimized in combination with the metal thickness gradient formed by the depth difference of the grooves; a double-sided alignment laser system is adopted to realize the alignment precision, and the problem of port isolation deterioration caused by pattern dislocation is radically inhibited.

The invention discloses a microstrip patch antenna working in a satellite communication ground receiving end frequency band, and belongs to the technical field of antennas. The antenna comprises a micro-strip radiation layer, a first dielectric substrate, an upper micro-strip feed network, a second dielectric substrate, a metal grounding plate, a third dielectric substrate and a lower micro-strip feed network which are tightly attached in sequence from top to bottom. The antenna disclosed by the invention works in a frequency band of 17.7 GHz-21.2 GHz, and in the frequency band of 17.7 GHz-21.2 GHz, parameters of S11 and S21 can be both lower than-10dB, and the axial ratio is lower than 2; the antenna adopts equal-amplitude double-path signal feed with the difference of 90 degrees, and has the advantages of small size, light weight, easy conformality, low cost and the like.

This invention relates to a miniature dual-frequency microwave anechoic chamber based on spatially distributed ultrathin absorbing materials. It includes a rigid cylindrical shell mounted on a support. An ultrathin dual-frequency electromagnetic wave absorbing unit and a transmitting antenna are attached to the inner wall of the rigid cylindrical shell. The ultrathin dual-frequency electromagnetic wave absorbing unit and the transmitting antenna are integrally formed, and the transmitting antenna is a microstrip patch antenna. This invention, through research on spatially distributed ultrathin electromagnetic wave absorbing materials, realizes a wavelength-scale miniature dual-frequency microwave anechoic chamber. The shape and size of the microwave anechoic chamber can be customized according to actual application requirements, and it is expected to be widely used in antenna measurement, microwave imaging, and other fields. This invention features low cost, simple construction, and portability.

The application discloses a tight-spacing antenna decoupling method and device based on deep learning, and a storage medium. The method comprises the following steps: acquiring tight-spacing antenna data; inputting the tight-spacing antenna data into an antenna decoupling structure prediction model to obtain decoupling structure parameters; and performing tight-spacing antenna decoupling processing according to the decoupling structure parameters. The antenna decoupling structure prediction model is obtained through the following steps: acquiring rectangular microstrip patch antenna information; calculating patch length and patch width; establishing a binary antenna model; performing electromagnetic field simulation processing by using a preset script program and electromagnetic simulation software to obtain simulation result data sets; constructing an initial convolutional neural network model; inputting the simulation result data sets into the initial convolutional neural network model according to mean square error, so that the initial convolutional neural network model is trained to obtain the antenna decoupling structure prediction model. The application realizes antenna decoupling, improves efficiency and accuracy, and can be widely applied to the field of wireless communication technology.

The invention belongs to the technical field of fuze antennas, and particularly relates to a radiation enhancement design method of an electromagnetic metamaterial focusing array fuze antenna, which specifically comprises the following steps of: establishing a relationship between structural characteristics of an electromagnetic metamaterial focusing array and incident wave and scattering characteristics, and determining the overall size and combination mode of the focusing array; designing a fuze antenna comprising the focusing array; metal walls are additionally arranged on the two sides of the fuze antenna patch by using a metal electric wall method, and the fuze antenna is selected as a microstrip patch antenna for large-angle beam scanning; electrical performance requirements and radiation performance requirements of the fuze antenna are converted into antenna characteristic mode requirements; the size of each unit of the electromagnetic metamaterial focusing array is determined according to the working frequency requirement of the fuze antenna, the corresponding characteristic mode is calculated, and the characteristic mode assists in fuze antenna design.

The application relates to the technical field of reconfigurable communication antenna devices, and particularly discloses a high-aperture-efficiency low-profile reconfigurable folded transmission array antenna design based on liquid crystals. The application aims to solve the problems of insufficient aperture efficiency and high profile in the existing reconfigurable folded array. The application designs a novel transmission unit, which integrates upper and lower radiation and receiving patches with polarization selection function and a liquid crystal phase shifter based on a strip line to realize phase compensation. In order to minimize the profile height, the main transmission array is composed of the novel transmission unit, while the auxiliary reflection array adopts a polarization conversion unit, and the interaction between the two is used to fold the transmission path of electromagnetic waves. At the same time, a microstrip patch antenna replaces the traditional horn antenna as the array feed source to reduce the overall profile. In order to improve the aperture efficiency, the liquid crystal phase shifter is carefully optimized to meet the requirement of 2-bit phase quantization, so as to improve the phase modulation accuracy and the accuracy of array phase distribution. Compared with the traditional space feed antenna and the folded array, the overall profile of the design is reduced by 2 / 3, the aperture efficiency is significantly improved, and excellent two-dimensional beam scanning performance is maintained.

The invention discloses an ultra wide band low radar cross section antenna based on an artificial magnetic conductor, and belongs to the technical field of ultra wide band antennas and electromagnetic stealth. The invention provides AMC units (AMC1 and AMC2) of two cross bending structures, and the AMC units (AMC1 and AMC2) are alternately arranged in a chessboard mode to form an AMC chessboard surface. The surface of the chessboard and the microstrip patch antenna are integrated in a coplanar mode, and the resonant frequency, the gain and the directional diagram of the antenna are kept basically unchanged while broadband RCS reduction is achieved. Test results show that RCS reduction not less than 10 dB can be realized in the frequency band of 12.3-27.0 GHz, the reflection coefficient and radiation characteristic of the antenna are well maintained, and the integrated structure gives consideration to radiation and stealth performance.

The invention discloses a low-profile dual-polarization filtering phased-array antenna based on a micro-mode SIW resonant cavity, and belongs to the technical field of antenna engineering. According to the invention, a micro-mode SIW resonant cavity is provided, and then two pairs of miniaturized micro-mode SIW filtering structures based on the micro-mode SIW resonant cavity are introduced into a feed structure of a microstrip patch antenna, so that a miniaturized dual-polarization filtering antenna unit is formed. The bandwidth is regulated and controlled by regulating and controlling the interdigital coupling groove between the two micro-mode SIW resonant cavities, the impedance matching is regulated through the U-shaped micro-strip transition structure, and the current balance and the electromagnetic shielding between the micro-strip patch antenna and the micro-mode SIW resonant cavities are respectively ensured by forming the arc-shaped groove and the open circuit column in the micro-strip patch antenna. The size of the finally optimized antenna unit is only 27mm * 27mm * 2.5 mm (0.45 lambda c * 0.45 lambda c * 0.04 lambda c, wherein lambda c is the central frequency wavelength of the free space). Simulation shows that the provided filtering phased-array antenna can guarantee 0-45-degree stable beam scanning in a 4.5-5.5 GHz passband, and suppression larger than 25 dB is achieved in a stop band.

This invention discloses a multi-band microstrip patch antenna, relating to the field of antenna technology. The multi-band microstrip patch antenna includes a rectangular patch antenna, a dielectric substrate, an air layer, a metal ground plane, and a coaxial feed line. The rectangular patch antenna is located on one side of the dielectric substrate, the metal ground plane is located on the other side, and the air layer is located between the dielectric substrate and the metal ground plane. The rectangular patch antenna includes multiple concentric rings, curved fractals, a curved flow, and a microstrip feed line. Curved fractals are applied to the outer ring of each concentric ring, and a magnetic cuboid is located on the rectangular patch antenna. Signals enter the multiple concentric rings and curved flow with curved fractals on the microstrip patch antenna via the coaxial feed line. Compared to existing antennas, the above-described multi-band microstrip patch antenna can achieve multi-band electromagnetic wave transmission and reception in the low-frequency band, and it has a simple structure, multiple functions, is easy to manufacture, and has low manufacturing costs.

The application discloses a ground penetrating radar ultra-wideband antenna and a ground penetrating radar system, which comprise two microstrip patches, an antenna dielectric plate, a first metal conductive loop and a second metal conductive loop; the two microstrip patches are symmetrically arranged on the upper surface of the antenna dielectric plate; wherein a feed gap is arranged between the front ends of the two microstrip patches, and the ends of the two microstrip patches are flush with the two short edge portions of the antenna dielectric plate; the first metal conductive loop and the second metal conductive loop are symmetrically arranged on the two short edge portions of the antenna dielectric plate; wherein the first metal conductive loop is vertically arranged on the upper portion of the end of the first microstrip patch, and the second metal conductive loop is vertically arranged on the upper portion of the end of the second microstrip patch; the application effectively increases the current path by using the metal conductive loop, expands the low-frequency bandwidth of the antenna, meets the ultra-wideband requirement, meanwhile, reduces the working center frequency of the antenna, realizes the miniaturization of the ground penetrating radar antenna, and is convenient for the integrated test of the ground penetrating radar system.

The application is a high-gain common-aperture beam scanning antenna with a large frequency ratio, the uppermost two dielectric plates are printed with a metasurface unit structure, and have a phase gradient change along a certain direction in a two-dimensional plane, the two dielectric plates are separated by a certain distance and can rotate around a normal axis. The lower two dielectric plates are fixed, a periodic structure is printed on the upper dielectric plate; a microstrip patch antenna for feeding a low-frequency high-gain resonant cavity antenna is printed in the center of the upper surface of the lower dielectric plate, and polarization conversion reflection units for a high-frequency band are printed around the microstrip patch antenna; the lower surface of the lower dielectric plate serves as a ground plate. A rectangular notch is respectively left in the center of the microstrip patch antenna and the ground plate, the lower side of the dielectric plate is connected with a standard WR34 waveguide, and the waveguide feeds the folded reflection array antenna for a high-frequency band. Electromagnetic waves can be transmitted and received in the Sub-6GHz frequency band and the millimeter wave frequency band in the field of 5G communication, and the high-frequency band can realize beam scanning.

The present application relates to a kind of portable dual-frequency microwave imaging darkroom, including hard cylindrical shell, hard cylindrical shell is installed on support, the geometric center of hard cylindrical shell is provided object to be measured, object to be measured is placed on two-dimensional rotating platform, double-frequency electromagnetic wave absorption unit is attached on the inner wall of hard cylindrical shell, double-frequency electromagnetic wave absorption unit, transmitting antenna and multiple receiving antennas are integrally formed, the transmitting antenna and receiving antenna are all using microstrip patch antenna, and radio frequency switch network controls the opening and shutdown of multiple receiving antennas.The present application uses ultrathin double-frequency electromagnetic wave absorption unit, can simultaneously realize near perfect absorption effect to electromagnetic wave from normal incidence direction and oblique incidence direction, and further constructs portable dual-frequency microwave imaging darkroom;With the help of the dual-frequency microwave imaging darkroom constructed, microwave imaging experiment based on inverse scattering principle can be measured on site, and is expected to be widely used in practical engineering application scenarios.

The invention discloses a small-size high-gain microstrip yagi antenna, and relates to the technical field of microwave communication, in particular to the microstrip antenna technology, which comprises a top metal patch layer, a middle dielectric substrate layer and a bottom metal grounding layer. The top metal patch layer comprises two rectangular reflection patches, a rectangular radiation patch and two rectangular guide patches, the two rectangular reflection patches are symmetrically distributed on the two sides of the microstrip line, and the radiation patch is connected with the feed network through the microstrip line; the radiation patch is provided with two rectangular grooves which are the same in size and are symmetrical, and the two rectangular guide patches are reduced in sequence. According to the design scheme of the application, the principles of the microstrip patch antenna and the yagi antenna are applied, and the antenna has high gain while keeping a small size, so that high-precision measurement of a target in a narrow space is realized.