| Dielectric resonator as the resonance unit in the microwave system, compared with traditional metal resonator, it has the advantages of small size, light weight, widely used in microwave system; As the dielectric constant increases, the resonance unit volume will be further reduced, the development of high-permittivity dielectric resonator will integrate resonance unit with circuit, reduce the volume of the microwave communications system greatly; So the development of dielectric resonator material has practical significance.This article study the (Zr, Sn) TiCO4(hereinafter referred to as the ZST) Microwave Dielectric Ceramics Process and application in-depth, main content:(l)Study in ZST Microwave Dielectric ceramic materials, cooling and modification. For synthesizing microwave ceramics with excellent performance at low temperatures, the paper added three oxidants (①ZnO+WO3;②ZnO+Bi2O3;③ZnO+La2O3+NiO), and analyze the performance comparatively when join three oxidants in ZST.(2)Study in ZST microwave ceramics used in the dielectric resonator antenna(hereinafter referred to as the DRA). The paper designed three dielectric resonator antenna, two of them are single-frequency dielectric resonator antenna which meet the wireless Local area network (hereinafter referred to as the WLAN) IEEE802.11b (2.4-2.483GHz) protocol, and another is dual-band dielectric resonator antenna that for WLAN IEEE802.11g (2.4-2.483GHz;5.15-5.35GHz) protocol.In ZST microwave ceramics process, the paper have three main conclusions:(1) Composite add La2O3and NiO, sintering temperature was significantly reduced to1330℃, and improve the density of ZST ceramics, but also increases the loss;(2) By adding Bi2O3, sintering temperature was significantly reduced to1310℃, achieve low-temperature furnace sintering, but its frequency temperature drift coefficient is12.39ppm/℃, it has certain gap with the reported ZST microwave ceramics similar to zero temperature drift coefficient;(3) By adding WO3/ZnO, at the1400℃sintering temperature (heating rate3℃/min, the cooling rate of10℃/h), The sample showed good microwave performance, at the resonant frequency about7.8GHz, the dielectric constant about38.2, the Q·f is43300GHz (using the standard Q·f>40000GHz), frequency temperature drift coefficient2ppm/℃(using the standard-10ppm/℃10ppm/℃). Compared with conventional solid state reaction method, although Q·f has a small gap, but the sintering temperature was reduced by200℃, reduce the cost of industrial production. So the best formula is ZW025in this paper.In ZST materials application, the paper has the following two conclusions:(1) the center resonant frequency of microstrip line fed cylindrical dielectric resonator antenna is2.42GHz, the resonance point return loss is41.39dB, the relative bandwidth is5.3%, the absolute bandwidth is130MHz, the input impedance is49.3Ω.(2)The center resonant frequency of the coplanar waveguide fed inverted L-shaped square dielectric resonator2.46GHz, resonant point return loss is36.38dB, the relative bandwidth is13.5%, the absolute bandwidth is330MHz, input impedance is49.85Ω. In comparison, the use of coplanar waveguide fed inverted L-shaped antenna can significantly increase the bandwidth, therefore, It was conducted actual machining tests, the center the resonant frequency of test result is2.8GHz, return loss is13.9dB, the relative bandwidth is2.85%, the resonant frequency at the antenna efficiency is60%, the maximum radiation gain is3.25dB. |
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