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CN-122026081-A - Ultrahigh-frequency-band low-interference antenna board and preparation method thereof

CN122026081ACN 122026081 ACN122026081 ACN 122026081ACN-122026081-A

Abstract

The invention discloses an ultrahigh frequency band low-interference antenna board and a preparation method thereof, wherein the ultrahigh frequency band low-interference antenna board comprises a PCB body, an antenna radiation unit integrally formed on the surface of the PCB body, and two coaxial SMA connectors fixedly arranged at preset positions of the PCB body, the PCB body comprises a first solder mask layer, a first copper foil, a first signal layer, a substrate layer, a grounding layer, a second signal layer, a second copper foil and a second solder mask layer, the substrate layer adopts an IT-150DA high-frequency special substrate, the surface treatment is electroless nickel gold plating, the copper foil thickness is 1oz, the two coaxial SMA connectors are respectively arranged at J1 and J2 positions of the PCB body, the antenna radiation unit, a circuit and the grounding layer of the PCB body form an integrated impedance matching network, and the PCB body is also integrated with a stray signal absorbing module. The invention effectively blocks multi-source interference such as space radiation, in-board crosstalk, connection end invasion and the like.

Inventors

  • WU WEI
  • WANG ZEPENG
  • ZHANG NA
  • WU ZHIWEI

Assignees

  • 福群电子（上海）有限公司

Dates

Publication Date
20260512
Application Date
20260415

Claims (10)

  1. 1. The ultra-high frequency band low-interference antenna board is characterized by comprising a PCB body, an antenna radiation unit integrally formed on the surface of the PCB body and two coaxial SMA connectors fixedly arranged at preset positions of the PCB body, wherein the PCB body comprises a first solder mask layer, a first copper foil, a first signal layer, a substrate layer, a grounding layer, a second signal layer, a second copper foil and a second solder mask layer, the substrate layer adopts an IT-150DA high-frequency special substrate, the surface treatment is chemical nickel-plating gold, the thickness of the copper foil is 1oz, the two coaxial SMA connectors are respectively arranged at J1 and J2 positions of the PCB body, the antenna radiation unit and a circuit and the grounding layer of the PCB body form an integrated impedance matching network, and the PCB body is further integrated with a stray signal absorption module which is electrically connected with the grounding layer.
  2. 2. The ultra-high frequency band low-interference antenna board according to claim 1, wherein the first signal layer is an ultra-high frequency antenna special circuit, only an antenna radiation unit connecting circuit is arranged, the grounding layer is an independent full-coverage shielding layer with the thickness not smaller than 0.01 inch and used for shielding space radiation interference and providing a low-impedance reflux path for high-frequency signals, the second signal layer is a connector and a high-frequency signal transmission circuit and is in accurate matching with the impedance of a coaxial SMA connector, and the first solder resist layer and the second solder resist layer are both prepared by adopting an SMOBC process.
  3. 3. The ultrahigh frequency band low-interference antenna board according to claim 1, wherein the antenna radiating units are of an array type radiating structure, the radiating surfaces of the antenna radiating units are of a non-shielding plane structure with the horizontal surfaces upwards, and the flatness of the radiating surfaces is less than or equal to 0.02mm.
  4. 4. The ultra-high frequency band low-interference antenna board according to claim 1, wherein the input/output impedance of the integrated impedance matching network is 50Ω radio frequency standard impedance, the input/output reflection coefficients S11 and S22 at 905MHz, 915MHz and 925MHz core frequency points are less than or equal to-15 dB, the transmission loss S11 and S22 at 300MHz-3GHz full frequency ranges are less than or equal to-10 dB, the transmission loss S21 of the PCB body at 905MHz frequency points is less than or equal to-18 dB, and the transmission loss S21 at 915MHz and 925MHz frequency points is less than or equal to-12 dB.
  5. 5. The ultra-high frequency band low-interference antenna board according to claim 1, wherein the spurious signal absorbing module is a high-frequency ferrite wave absorbing patch, a grounding layer attached to the PCB body corresponds to the peripheral area of the antenna radiating unit, the wave absorbing band covers 300MHz-3GHz, the spurious signal absorbing efficiency is more than or equal to 85%, and the spurious signal absorbing module and the grounding layer form a spurious signal grounding release channel.
  6. 6. The ultra-high frequency band low interference antenna board according to claim 1, wherein the grounding layer of the PCB board body forms a closed-loop type grounding shielding surface in the antenna radiating unit area, the shielding surface is arranged around the whole circumference of the antenna radiating unit, and the closed-loop gap is less than or equal to 0.005 inch.
  7. 7. The ultra-high frequency band low interference antenna board according to claim 1, wherein the solder mask layer of the PCB body is made of a temperature-resistant and moisture-proof epoxy resin solder mask material, the temperature-resistant range is-40 ℃ to 125 ℃, the first copper foil and the second copper foil are high-conductivity electrolytic copper foils, and the conductivity is more than or equal to 58MS/m.
  8. 8. A method for manufacturing an ultrahigh frequency band low-interference antenna board according to any one of claims 1 to 7, comprising the steps of: s1, selecting and preprocessing a PCB substrate, namely selecting a special substrate with homogenization IT-150DA high frequency, cutting the special substrate into a plate body with the thickness of 290mm multiplied by 140mm multiplied by 5.7mm by high-precision cutting equipment, cleaning the surface of the plate body by adopting a plasma cleaning process, removing surface impurities, oxide layers and greasy dirt, and cleaning the surface roughness Ra of the cleaned plate body to be less than or equal to 0.05 mu m; S2, laminating the high-conductivity electrolytic copper foil with the thickness of 1oz on two sides of the pretreated IT-150DA substrate through a hot-pressing process, wherein the hot-pressing temperature is 180+/-5 ℃, the hot-pressing pressure is 35+/-2 MPa, the surface of the copper foil is treated through a chemical nickel-gold plating process after lamination, the thickness of a nickel layer is 3-5 mu m, and the thickness of a gold layer is 0.05-0.1 mu m, so that a nickel-gold conductive layer with low contact resistance is formed; S3, manufacturing a circuit, namely manufacturing a first signal layer, a ground layer and a second signal layer on a board body in a layering manner by adopting a laser etching process, controlling the laser etching precision within +/-0.001 inch, ensuring that the minimum line width of a finished product is 0.008 inch and the line width tolerance is +/-20%, simultaneously adopting a numerical control drilling machine to drill, wherein the drilling specification is 0.040 inch, the drilling tolerance is +/-0.003 inch, and adopting a precise edging device to perform deburring treatment on all corners after drilling, thereby ensuring that the maximum height of burrs is less than or equal to 0.381mm; S4, integrating a stray signal absorbing module, namely attaching a high-frequency ferrite wave absorbing patch to a preset area of the periphery of the antenna radiation unit corresponding to the grounding layer, and adopting conductive adhesive to realize the electrical connection between the patch and the grounding layer to form a stray signal grounding release channel, wherein the conductivity of the conductive adhesive is more than or equal to 100MS/m; S5, preparing a solder mask layer accurately, namely preparing a green epoxy resin solder mask layer on two sides of the plate body by adopting an SMOBC bare copper upper solder mask process and a screen printing and ultraviolet curing process, so as to realize accurate solder mask coverage of a bare copper area, wherein the coverage accuracy of the bare copper is more than or equal to 99%, and the thickness of the cured solder mask layer is 15-25 mu m; S6, carrying out standardized welding on the coaxial SMA connectors, namely respectively carrying out positioning welding on the two ultrahigh frequency low-insertion-loss coaxial SMA connectors at the J1 and J2 positions of the PCB body, adopting A reflow soldering process according to the IPC-A-610E-IICLASS level 2 standard, and ensuring that the pins and the bonding pads are completely wetted by adopting the reflow soldering process, the wetting rate is more than or equal to 98%, no cold soldering or cold soldering defect exists, and carrying out tensile strength detection after welding, so that the connection tensile strength is more than or equal to 50N; S7, integrally forming and adapting the antenna radiation unit, namely integrally manufacturing the array antenna radiation unit on a first signal layer of the PCB body by adopting a laser engraving process according to 300MHz-3GHz frequency band wavelength characteristic simulation design parameters, and calibrating resonance characteristics aiming at 860MHz-1GHz core working frequency band to enable resonance frequency deviation to be less than or equal to +/-5 MHz; s8, detecting a multi-dimensional finished product, namely performing full performance detection, appearance detection and environment adaptability initial detection on the prepared antenna board, wherein the performance detection comprises 905/915/925MHz core frequency points and 300MHz-3GHz full-frequency band S11, S22 and S21 parameter detection, so that parameters meet the threshold requirement of claim 4, the appearance detection does not have burrs, scratches, solder mask falling and connector skew defects, the environment adaptability initial detection comprises normal-temperature dampproof, low-temperature-40 ℃ and 125 ℃ short-time tolerance test, no performance attenuation is caused after the test, and meanwhile, circuit on-off, connector contact performance and stray signal absorption efficiency are detected, and the finished product is obtained after all indexes are qualified.
  9. 9. The method for manufacturing the ultra-high frequency band low interference antenna board according to claim 8, wherein in S3, the ground layer is made by full-coverage etching to form an independent shielding layer with a thickness not less than 0.01 inch, and a closed loop shielding surface processing station is reserved in an antenna radiating unit area, a closed loop gap is not more than 0.005 inch, and the shielding protection of the subsequent antenna radiating unit is preset; S7, performing real-time test calibration by using a vector network analyzer for the resonance characteristic calibration of the antenna radiating unit, and enabling the resonance characteristic of a core working frequency band to reach the optimum through fine adjustment of the size and the distance of the radiating unit, wherein the signal receiving and transmitting efficiency of the radiating unit after calibration is more than or equal to 90%; In S8, the spurious signal absorption efficiency is detected by adopting a spurious signal generator matched with a spectrum analyzer, the detection frequency range covers 300MHz-3GHz, the spurious signal absorption efficiency is ensured to be more than or equal to 85%, the circuit on-off detection is performed by adopting a high-precision multimeter, the on-off judgment threshold value is that the on-off resistance is less than or equal to 0.1 omega, and the off-off resistance is more than or equal to 10MΩ.
  10. 10. The method for manufacturing the ultra-high frequency band low-interference antenna board is characterized by further comprising the step S9 of packaging and marking finished products, wherein the antenna board which is qualified in detection is subjected to vacuum packaging by adopting an anti-static and moisture-proof packaging bag, a drying agent is placed in the packaging bag, and meanwhile, an identification label is stuck on the surface of the antenna board, and core parameters, production batches, qualified detection information and core frequency point marks are marked.

Description

Ultrahigh-frequency-band low-interference antenna board and preparation method thereof Technical Field The invention relates to the technical field of antenna plates, in particular to an ultrahigh frequency band low-interference antenna plate and a preparation method thereof. Background The application of the satellite communication technology is mainly embodied in two aspects of military use and civil use (industrial and agricultural production), and the rapid development of the wireless communication technology also makes the development of the satellite communication technology field rapid. Satellite communication receives and transmits signals primarily by means of an antenna, the size of which is primarily determined by the operating frequency. The prior publication No. CN110534878A discloses a miniaturized ultrahigh frequency antenna based on split resonant ring loading, which comprises an upper substrate, a lower substrate, three antenna units, at least three vertical substrates, split resonant rings, a metal floor, a feed network, three feed probes and three feed probes, wherein the three antenna units are rotationally and symmetrically arranged between the upper substrate and the lower substrate, the three vertical substrates are rotationally and symmetrically arranged between the upper substrate and the lower substrate, the split resonant rings are respectively printed on the largest surface of each vertical substrate, the split resonant rings on the adjacent vertical substrates are electrically connected, the metal floor is printed on the upper surface of the lower substrate, the feed network is printed on the lower surface of the lower substrate and is used for receiving ultrahigh frequency signals and generating three-way sequence feed signals with the same amplitude and the phase difference of 120 degrees in sequence, and the three feed probes are arranged between the upper substrate and the lower substrate and are used for feeding the three-way sequence feed signals to the three antenna units respectively. In the prior art, common substrates such as common FR-4 and the like are mostly adopted, no special low dielectric loss design for the ultra-high frequency band exists, the stability of the dielectric constant is poor, the signal energy loss is serious in the high frequency band of 300MHz-3GHz, the signal distortion is easily caused by the fluctuation of the dielectric constant, and the transmission integrity of high-frequency small signals cannot be ensured. Disclosure of Invention The invention aims to provide an ultrahigh frequency band low-interference antenna board and a preparation method thereof, which are used for solving the problems in the prior art. The ultra-high frequency band low-interference antenna board comprises a PCB board body, an antenna radiation unit integrally formed on the surface of the PCB board body and two coaxial SMA connectors fixedly arranged at preset positions of the PCB board body, wherein the PCB board body comprises a first solder mask layer, a first copper foil, a first signal layer, a substrate layer, a grounding layer, a second signal layer, a second copper foil and a second solder mask layer, the substrate layer is an IT-150DA high-frequency special substrate, the surface treatment is electroless nickel gold plating, the copper foil thickness is 1oz, the two coaxial SMA connectors are respectively arranged at J1 and J2 positions of the PCB board body, the antenna radiation unit, a circuit of the PCB board body and the grounding layer form an integrated impedance matching network, and the PCB board body is further integrated with a stray signal absorbing module which is electrically connected with the grounding layer. The antenna comprises a first signal layer, a second signal layer, a first solder mask layer, a second solder mask layer and a coaxial SMA connector, wherein the first signal layer is a special line of an ultrahigh frequency antenna, only an antenna radiation unit connecting line is arranged, the ground layer is an independent full-coverage shielding layer with the thickness not smaller than 0.01 inch and is used for shielding space radiation interference and providing a low-impedance reflux path for high-frequency signals, the second signal layer is a connector and a high-frequency signal transmission line and is in accurate matching with the impedance of the coaxial SMA connector, and the first solder mask layer and the second solder mask layer are both prepared by adopting an SMOBC process. Preferably, the antenna radiating unit is of an array type radiating structure, the radiating surface of the antenna radiating unit is of a horizontal upward non-shielding plane structure, and the flatness of the radiating surface is less than or equal to 0.02mm. Preferably, the input/output impedance of the integrated impedance matching network is 50 omega radio frequency standard impedance, the input/output reflection coefficients S11 and S22 at