ENVIRONMENT-FRIENDLY MICROWAVE DIELECTRIC CERAMIC MATERIAL FOR SMALL NAVIGATION ANTENNA

Abstract

The present invention relates to an environment-friendly microwave dielectric ceramic material for small navigation antenna, which is applied to the microwave components such as dielectric resonator, filter, oscillator, cellphone antenna and GPS of small navigation antenna transceiving satellite communication system. The main powder ingredients of the raw material of the present invention include: CaCO.sub.3, TiO.sub.2, MgO, ZnO, Al.sub.2O.sub.3 and a micro amount of additives: SiO.sub.2 and V.sub.2O.sub.5. The present invention has low sintering temperature resulting in low power consumption, low dielectric constant, high quality factor and stable resonance frequency temperature characteristic.

Claims

1. An environment-friendly microwave dielectric ceramic material for small navigation antenna, with the main powder ingredients of the raw material including: CaCO.sub.3, TiO.sub.2, MgO, ZnO, Al.sub.2O.sub.3 and a micro amount of additives; the dielectric ceramic material is characterized in that: the micro amount of additives are SiO.sub.2 and V.sub.2O.sub.5, and the content of each ingredient is: CaCO.sub.3 24%-30%; TiO.sub.2 24%-36%; MgO 23%-33%; ZnO 10%-15%; Al.sub.2O.sub.3 1%-6%; SiO.sub.2 0.8%-1.4%; V.sub.2O.sub.5 0.6%-1.7%; the manufacturing method of the dielectric ceramic material is: {circle around (1)} weighing CaCO.sub.3, TiO.sub.2, MgO, ZnO, Al.sub.2O.sub.3, SiO.sub.2 and V.sub.2O.sub.5 powders according to the ingredient requirement, putting the powders in the barrel of a ball mill, and conducting ball milling and stirring for 4-6 hours; {circle around (2)} adding 15% PVA water solution to the milled slurry and stirring for 1-2 hours; {circle around (3)} molding by dry pressing with a pressure of 500-800 MPa and potting; {circle around (4)} preserving heat at a temperature of 1200 C.-1280 C. for 2-4 hours, completing glue expelling and sintering at one time, and thus the microwave dielectric ceramic material for small navigation antenna is obtained.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. 1 is a diagram showing the relationship between sintering temperature and quality factor Q-value.

[0027] FIG. 2 is a characteristic curve showing the change of resonance frequency along with temperature change.

[0028] FIG. 3 is a curve showing the relationship between quality factor Q-value and resonance frequency.

DETAILED DESCRIPTION

[0029] The present invention is realized through the following technical solution.

[0030] An environment-friendly microwave dielectric ceramic material for small navigation antenna, with the main powder ingredients of the raw material including: CaCO.sub.3, TiO.sub.2, MgO, ZnO, Al.sub.2O.sub.3 and a micro amount of additives: SiO.sub.2 and V.sub.2O.sub.5. Table 1 shows the data of each embodiment, and Table 2 shows the performance of each embodiment.

TABLE-US-00001 TABLE 1 Glue Expelling Glue Expelling Stirring and and Sintering and Sintering Embodiment CaCO.sub.3 TiO.sub.2 MgO ZnO Al.sub.2O.sub.3 SiO.sub.2 V.sub.2O.sub.5 Milling Time Temperature Time No. (wt %) (wt %) (wt %) (wt %) (wt %) (wt %) (wt %) (H) ( C.) (H) 1 24 30 28.5 10 6 1.2 0.6 4 1200 3 2 26 27 28 12 5 0.8 1.2 4 1220 3.5 3 30 24 33 10 1 0.8 1.2 4 1240 4 4 25 36 23 10.5 3 1 1.5 4 1260 4 5 24 30 26 13 4 1.3 1.7 4 1280 4 6 28 32 25 10 2 1.4 1.6 4 1270 2 7 24 27.5 27 15 4 1.2 1.3 4 1250 2.5 8 25 28 27.5 12 6 0 1.5 4 1310 3 9 23 28 30 14.5 4 0.5 0 4 1320 3 10 27 30 31 10 2 0 0 4 1360 3

TABLE-US-00002 TABLE 2 Gongtian Electronic Quality Ceramics Outer Dielectric Resonance Factor Temperature Embodiment Technology Diameter Thickness Constant Frequency Q-Value Characteristic r No. Co., Ltd. Type (mm) (mm) r (MHz) (GHz) (ppm/ C.) 1 DRT1575 24.95 4.0.5 21.5 1575 4802 3 2 DRT1575 24.92 4.05 21.8 1574 4921 3.2 3 DRT1575 24.95 4.06 21.8 1573 4925 2.8 4 DRT1575 24.96 4.04 21.6 1573 4960 2.5 5 DRT1575 24.91 4.05 21.8 1572 4943 2.2 6 DRT1575 24.93 4.05 21.6 1576 4834 2.2 7 DRT1575 24.95 4.02 21.5 1577 4901 2.3 8 DRT1575 25.12 4.02 18.9 1575 2206 5 9 DRT1575 25.5 4.03 18.5 1574 3143 6 10 DRT1575 25.8 4.06 16 1574 1809 8

CONCLUSION

[0031] It can be seen from comparison items 8, 9 and 10 of Table 1 that the sintering temperature will significantly increase without the addition of SiO.sub.2 and V.sub.2O.sub.5;

[0032] It can be seen from comparison items 8, 9 and 10 of Table 2 that the dielectric constant and the quality factor will decrease without the addition of SiO.sub.2 and V.sub.2O.sub.5;

[0033] FIGS. 1-2 summarize the change tendency of formulation and performance, which facilitates the adjustment of formulation to obtain the microwave dielectric ceramics of required performance;

[0034] The quality factor Q-value of resonance frequency in FIG. 1 will increase with the frequency, and will decrease when the temperature reaches 1300 C.;

[0035] The characteristic tendency chart of the relationship between temperature and resonance frequency in FIG. 2 shows that the resonance frequency varies when the temperature is between 40 C. and +80 C., and the medium frequency offset for the resonance frequency of 1.575 GHz is within 5 MHz (Tf=5 ppm/ C.), so the frequency stability is good;

[0036] FIG. 3 is a curve showing the relationship between quality factor Q-value and resonance frequency. The Q-value will increase with the frequency, will be the largest when the frequency reaches 1575 MHz, and will decrease when the frequency further increases, which indicates that the dielectric ceramics of this formulation is suitable for resonance circuit with a resonance frequency of 1575 MHz.