Design and verification of a high bandwidth metamaterial based on daily ceramics and its thermal conductivity

High temperature resistant metamaterial absorbers with broadband and high performance is a promising research field. At present, many reported absorbing materials have the defects of single absorption mechanism, temperature sensitivity, and low temperature resistance. To expand the high-temperature performancs, a daily ceramics-based metamaterial absorber was proposed and verified. The absorption band was excited by the local surface plasma polarization (LSP) mode and the surface plasma polarization (SPP) mode resonance between disk arrays, and the dielectric loss mode resonance of the ceramic substrate. The effects of structural parameters, temperature, preparation process, and type of ceramic substrate on the absorption properties of the metamaterial were measured. The measurement results show that the metamaterial absorber is obvious temperature stability. The absorption band was strengthened by increasing the thickness of the ceramic substrate and the diameter of the disk array. The average value of absorption band was less affected by the preparation technology of daily ceramic substrate. The average absorption based on four preparation technologies (Chemical vapor deposition, Microwave induced synthesis, Sol-gel method, Carbothermal reduction method) are: 0.861, 0.882, 0.857, and 0.842, respectively. The average absorption based on four daily ceramics (SiC, ZrSiO 4 , TmFeO 3 , and ZrSnTiO) were: 0.861, 0.776, 0.908, and 0.857, respectively. In addition, the thermal conductivity and thermal resistance of daily ceramics were important parameters to measure the thermal resonance performance of the ceramic-based metamaterial absorber. The results confirmed the effect of ceramic on the thermal conductivities (thermal response current, thermal resistance and thermal conductivity). Therefore, the proposed daily ceramic-based metamaterial absorber has the following advantages: absorption is temperature-independent, and the high temperature metamaterial is capable of excellent heat conductivity.


Introduction
In recent years, based on rich resonance properties, metamaterials/metasurfaces containing subwavelength periodic structures had attracted the attention of researchers [1][2][3][4][5]. Many metamaterials/metasurfaces with novel functions were proposed, verified, and optimized. These metamaterials/metasurfaces were used to developping optoelectronic devices [6][7][8][9][10]. On the one hand, in the current material research field, absorbing the energy of electromagnetic waves was an expected hot spot, especially the application of high-temperature absorbing materials. High-temperature absorbing materials were widely concerned and continuously studied by researchers because of their high temperature resistance and electromagnetic wave absorption. At present, the research of high temperature absorbing materials mainly adopted doping, modification, morphology control and other methods to adjust the absorbing performances. More and more high temperature absorbing materials were discovered and applied. For example, carbon-based high-temperature absorbing materials, Cao et al prepared a carbon fiber/silica high-temperature absorbing material by using the classical method of preparing domestic ceramics, hot-pressing sintering method. This high-temperature absorbing material achieved an absorption performance of less than −7.5 dB in the range of room temperature to 600°C [11]. Silicon carbide absorbing materials were become widely studied high temperature absorbing materials due to their good wear resistance, good thermal stability and high temperature resistance. Due to the poor absorption performance of pure SiC in the GHz band, researchers often use doping modification to improve the absorption performance [12]. High temperature oxidation absorption materials were verified and applied by researchers. For example, Zhou et al proposed a ZnO composite material and applied it to omnidirectional antennas. However, the high temperature absorption performances of these materials were not high due to the large imaginary part of the dielectric constant [13]. Since the material parameters were as a function of temperature, the properties of these reported high-temperature absorbing materials show obvious temperature dependence, which is not conducive to industrial applications. On the other hand, in order to enhance the energy absorption performance, various performance-rich metamaterial absorbers were proposed and verified [14][15][16][17]. In order to expand the bandwidth of metamaterial absorbers, many novel structural strategies were proposed and verified. Li et al proposed a multi-band metamaterial absorber. An electric-field-coupled resonator of the same size was applied to the same structure and excites multiple resonance modes [18]. Liu et al verified a multi-band metamaterial absorber composed of two cruciform micro-structures [19]. Li et al validated a metamaterial absorber with three resonant modes by using three separated metal rings [20]. However, as the raw materials used in many reported metamaterial absorbers are composed of metal and low dielectric polymer materials, the excited bandwidth was limited by the resonance mode of the metal layer. In particular, the high temperature absorption performance of these metamaterial absorbers had not received much attention from researchers. Therefore, the application of ceramics in metamaterial absorbers to obtain high temperature absorption performance was become a hot topic in materials research. Yang et al designed and verified a metamaterial absorber containing SrTiO 3 dielectric ceramics, whose absorption performance was enhanced in the 13-14 GHz band [21]. Li et al applied a ceramic square column Ba0.6Sr0.4TiO3-0.3la (Mg0.5Ti0.5)O3 with perovskite structure to a metamaterial absorber and excited multiple absorption resonance modes in the 6.4 GHz-8.37 GHz band [22]. Yang et al designed a metamaterial absorber using C/Al 2 O 3 blend fired ceramics. Simulation and measurement results show that this ceramic-based metamaterial absorber excited a strong absorption peak at 11 GHz [21]. Yang et al designed and optimized the absorption performance of the metamaterial absorber using TiO 2 /Al 2 O 3 mixed ceramics and periodic metal discs [23]. Obviously, the ceramic-based metamaterial absorber with a working frequency band in the GHz range had attracted the attention of researchers [10,12,[21][22][23]. However, these reported GHz-range ceramic-based metamaterial absorbers shown the following defects : the larger structure size was not conducive to microelectronic integration, the larger energy consumption, the bandwidth of the absorption band was limited by the resonance mode, and the electromagnetic wave penetration performance was low, etc In addition, these ceramic-based metamaterial absorbers were still temperature-dependent, with bandwidth limited by resonance modes. Unfortunately, the thermal conductivity of metamaterial absorbers based on daily ceramics had not been revealed by researchers. The thermal conductivity was directly related to the temperature sensitivity of ceramic-based metamaterial absorbers. Revealing the heat conduction properties was conducive to expanding the performance range of ceramic-based metamaterial absorbers and the application range of thermal sensing.
Therefore, in order to expand the performance of high-temperature metamaterials, a absorber based on daily ceramics was designed and validated in this paper. Traditional high temperature absorbing materials show a single absorption band and strong dependence on electromagnetic parameters, which results in the corresponding temperature sensitivity and other shortcomings. Most wave-absorbing metamaterials do not tolerate high temperatures. At the same time, ceramic based metamaterials with high temperature absorption resistance had not received much attention from researchers. Therefore, the proposed daily ceramic-based metamaterial absorber had the following advantages: (a) the absorption performance was insensitive to temperature (this was because the absorption band was excited based on three modes of resonance: LSP mode resonance, SPP mode resonance and ceramic substrate dielectric loss mode). (b) Thermal conductivity of the metamaterial was high. (c) The ceramic-based metamaterial does not contain any metal layers and avoids strong resonant reflection patterns. The results show that the structure parameters, the preparation process and the type of ceramic substrate were the factors that affect the absorption performance of the metamaterial. The thermal conductivities of four ceramic metamaterials were measured and calculated. These results confirmed the effect of ceramic type on thermal conductivity (thermal response current, thermal resistance and thermal conductivity).

Models and samples
The structural design of the ceramic-based metamaterial absorber was shown in figure 1. The bottom layer was a complete household ceramic (mainly composed of SiC) material, while the top disk array was made of conductive TiB 2 ceramics with good conductivity. The geometric parameters of the structure were shown in table 1. High frequency structural simulator (HFSS) was used to simulate the structure. A metamaterial absorber can be made by: (a) Applying SU-8 layers to the surface of a glass plate using a glue spinner (MSC-400Bz-6N spinner). SU-8 was dried and cured using a hot plate (C-MAG HP10). (b) The glass substrate was fixed in the evaporation chamber of the coating machine (ZZL-U400C), and the domestic ceramic layer was covered on the SU-8 surface by vapor deposition method. (c) Coating conductive ceramic TiB 2 layer on the ceramic surface using the same equipment (ZZL-U400C) and method (vapor deposition). (d) Soaked the semi-finished product in acetone to remove the SU-8 layer. The composite ceramic layer was cleaned with ultra-pure water and dried with a hot plate (C-MAG HP10). (e) A disk array of TiB 2 conducting ceramics was prepared using laser etching by fixing the composite ceramic layer on the horizontal table of the facility (CABL-9000C). (f) Sample of the metamaterial absorber shall be cleaned by ultrasonic device. Absorption efficiency of the metamaterial absorber was obtained by using fourier spectrometer, as shown in figure 2(a). The scanning electronic material (SEM) of the metamaterial sample uses scanning electron microscope (JSM-7610F), as shown in figure 2 The absorptivity of the metamaterial sample was obtained at normal temperature and pressure, as shown in figure 2(a). During the experimental measurement, the electromagnetic wave is excited by the wave source and reaches the surface of the ceramic-based metamaterial absorber. Three resonant behaviors are excited by electromagnetic waves : one part of the energy of the electromagnetic wave is reflected into the air by the ceramic-based metamaterial absorber (reflectivity, R), another part of the energy penetrates the ceramic-based metamaterial absorber and reaches the receiving port (transmittance, T), and the last part of the energy is absorbed during the penetration of the ceramic-based metamaterial absorber (absorptivity, A). Therefore, assuming that the energy of the electromagnetic wave is 1, there is the following relationship : figure 2, the absorption rate of the ceramic-based metamaterial absorber ( including measurement results, simulation results, and calculation results ). Within the target frequency band (from 5 THz to 40 THz), an absorption band (from 6.4 THz to 34.5 THz). The bandwidth of the ceramic-based metamaterial absorber is 28.10 THz. In this absorption band, the average absorption rate is 0.861, as shown in figure 2. The bandwidth of the absorption band is an important factor to measure the performance of the metamaterial absorber. Many novel structural design strategies have been applied to the development of large bandwidth metamaterial absorbers [24]. For example, Zhaoning Yang et al designed and measured a wide-band radar absorber based on  TiO2/Al2O3 ceramic with a frequency range of 8.2-18 GHz [25]. Qin Feng et al simulated a Cross metal array metamaterial absorber and obtained an absorption band with a bandwidth of 15 THz [26]. The bandwidth of the absorption band shown in figure 2 is greater than these reported results. Meanwhile, the simulated and calculated absorption rates are also shown in figure 2 (red and blue curves). The theoretical model is applied as follows [27]: Here, the e ¥ is high-frequency bulk permittivity. The w o is soft mode frequency. The f is oscillator strength. In simulations, the electromagnetic boundaries are set to be the ideal electromagnetic boundaries [28]. During the simulation, the scanning frequency was set to 0.01 THz. The excitation port of the electromagnetic wave is located directly above the metamaterial structure, and the receiving port is located directly below it. The perfect matching layer is used to eliminate the energy scattering. The properties and parameters of the material are set according to the automatic matching mode of the simulation software system, without manual input. The simulated average absorption rate was 0.887 and the calculated average absorption rate was 0.848. The measurement results show that the sample based on daily ceramic had obvious large bandwidth and stable absorption performance at normal temperature and pressure. As can be seen from figure 2, the absorption band of the absorber was smooth, which means that the coupling between resonance modes and electromagnetic wave was stable in the target frequency band. This was conducive to enhancing the absorption performance of the sample.

Results and discussion
In order to reveal the basic principle of the absorber, electric field intensity distributions of different frequencies were simulated, as shown in    In order to verify the high temperature absorption characteristics of the ceramic-based metamaterial absorber, the absorption rates at different temperatures were measured, as shown in figure 5. The measured temperatures were set to 300 K, 600 K, 900 K and 1200 K, respectively. The average absorption rates were: 0.861, 0.865, 0.868, and 0.873, respectively. The bandwidths obtained under different temperature conditions were: 28.10 THz, 28.13 THz, 28.14 THz, and 28.16 THz, respectively, as shown in figure 5. By comparing these measurements, the average absorptivity and bandwidth of the ceramic-based metamaterial absorber were not sensitive to temperature. Therefore, the ceramic-based metamaterial absorber was high temperature absorption stability. This was mainly because the performance of the daily ceramic-based metamaterial absorber was mainly based on the LSP mode, SPP mode, and dielectric loss mode, as shown in figure 3. The excitation and resonance intensity of these modes (LSP mode, SPP mode, and dielectric loss mode) were independent of ambient temperature. At present, many metamaterials with resonance properties depend on temperature conditions were proposed and verified by researchers. Hasan Kocer et al designed and measured a metamaterial absorber based on a VO 2 . By changing the temperature conditions, the performance of the absorber can be changed from 90% to 20% [29]. Ben-Xin Wang et al designed and simulated a metamaterial absorber based on substrate strontium titanate (STO) dielectric layer. When the temperature was 150 K-400 K, the resonant frequency of the metamaterial absorber was shifted from 0.20 THz to 0.111 THz [30]. In order to further reveal the hightemperature stability of the metamaterial absorber, the electric field distributions under different temperature conditions were calculated (in the cross section along the z-axis), as shown in figure 6. With the increase of temperature, the resonance intensity of LSP mode, SPP mode, and dielectric loss mode was not enhanced, as shown in figures 6(a)-(d). Therefore, the performance of the domestic ceramic, or metamaterial absorber, does not show a temperature dependence, as shown in figure 3. In order to visually verify the temperature independence of LSP mode and SPP mode, the electric field strength under different temperature conditions  According to the simulation results in figures 3 and 6, the proposed metamaterial absorber was based on LSP mode, SPP mode, and dielectric loss mode. These resonance modes were sensitive to structural parameters. Therefore, it was necessary to reveal the influence of structural parameters on the absorption properties. First, the thickness of the daily ceramic layer h2 was gradually increased during experiments. The parameter h2 was set to: 6 μm, 8 μm and 10 μm. The average absorption rates were 0.861, 0.894, and 0.934. The measured bandwidths were 28.10 THz, 28.12 THz, and 28.13 THz, as shown in figure 7. The difference in the average absorption rate was 0.073, while the bandwidth was essentially unchanged. The dielectric loss of daily ceramic layer was increased, which result in the enhancement of the average absorption rate. According to figures 3 (e)-(f), it can be seen that the daily ceramic layer revealed obvious absorption effect on the energy of electromagnetic wave. Increasing the thickness of domestic ceramic layer can enhance the overall absorption performance of the metamaterial structure. However, the excitation of LSP mode and SPP mode was only related to the ceramic disk array. The resonances between the LSP and SPP modes were not affected by the thickness of daily ceramics, so the bandwidth of the ceramic-based metamaterial absorber was stable. It should be noted that there was no linear relationship between absorption enhancement and thickness. With the increase of thickness, the absorption band increases slowly.
Second, the diameter of the ceramic disk array d was gradually increased during experiments. Parameter d was set to: 10 μm, 10.5 μm and 11 μm. The average absorption rates were: 0.861, 0.861, and 0.862. The measured bandwidths were: 28.10 THz, 30.05 THz, and 32.34 THz, as shown in figure 8. The bandwidth of the daily ceramic-based metamaterial absorber was enhanced with the increase of parameter d, as shown in figure 8. This was because the resonance of the SPP mode was depend on the upper surface of the ceramic disk array, as shown in figure 3 (d). When parameter d was increased, the upper surface area of the ceramic disk array was directly increased, which leaded to the resonant frequency of the SPP mode move to high frequency and the bandwidth increase, as shown in figure 8. Therefore, the performance of the ceramic based metamaterial absorber can be enhanced by optimizing the structural parameters (h2, d).
Thirdly, the influence of the preparation process of domestic ceramics on the performance of the metamaterial absorber also needs to be revealed. According to the measurement results in figure 7, the dielectric loss of daily ceramics was an important factor in the formation of the absorption band, which was related to the preparation process. Therefore, the influence of preparation processes on the performance of the metamaterial absorber was measured, as shown in figure 9. These preparation technologies were: Chemical vapor deposition, Microwave induced synthesis, Sol-gel method, and Carbothermal reduction method. The measurement results show that the bandwidth of the metamaterial absorber was basically unchanged under different preparation conditions, as shown in figure 9. This bandwidth was mainly determined by the resonance frequencies of the LSP and SPP modes, as shown in figure 3. The resonance frequencies and intensities of the LSP and SPP modes on the surface of disk array were not affected by these preparation processes of daily ceramic layer. The obtained average absorptivities by these preparation processes were: 0.861, 0.882,0.857, and 0.842. By comparison, the average absorption efficiency of the ceramic-based metamaterials prepared by the Chemical vapor deposition process and the Sol-gel method were basically the same. The average absorption rate obtained by Microwave induced synthes obtained 0.875, while that by Carbothermal reduction method was 0.843, as shown in figure 8. According to the measurement results in figure 9, the absorption properties of the metamaterial were not strongly affected by the preparation processes. The absorption bandwidth of the ceramic-based metamaterial was independent of the preparation process of the daily ceramic.
In recent years, metamaterials based on ceramics had attracted the attention of many researchers. In order to expand the performance of metamaterial absorbers, various functional ceramics were applied in structural design. For example, Yuan et al prepared SiC ceramics by doping Ni powders. The absorptive properties of the improved SiC ceramic structures were obviously enhanced and show a strong temperature dependence [31]. Luo et al prepared Zn-O/ZN-SiO 4 composite ceramics by doping Zn-O particles. This method can increase the dielectric loss of ceramics and enlarge the bandwidth [32,33]. Zeng X X et al prepared metamaterials based on TmFeO3 ceramics and obtained higher dielectric constants through 3D printing and laser direct writing techniques [34,35]. Jeon et al proposed and simulated a resonator based on ZrSnTiO ceramics (resonant frequency of about 6.876 GHz) [36]. Fourthly, the influence of the ceramic substrates on the absorption performance of the metamaterial was also measured, as shown in figure 10. In experiments, different kinds of ceramic substrates were applied to the structural design of the metamaterials: SiC, ZrSiO 4 , TmFeO 3 , and ZrSnTiO. The average absorption rates of the four daily ceramic substrates were: 0.861, 0.776, 0.908, and 0.857,  respectively. According to the measurement results in figure 10, the performance of the metamaterial absorber was related to the type of daily ceramic substrate. This was because the excitation mechanism of the absorption band was related to three factors: the LSP and SPP modes resonance excitation of the disk array surface, and the dielectric loss of the daily ceramic substrate, as shown in figures 3 and 6. These ceramic substrates (SiC, ZrSiO 4 , TmFeO 3 , and ZrSnTiO) contained different main compositions and preparation processes, which result in different dielectric loss properties. Therefore, different kinds of ceramic substrates can be selected in industrial applications according to actual needs. During the measurement, the absorption bandwidth of the ceramicbased metamaterial was basically stable.
Finally, the thermal conductivity of the ceramic based metamaterial absorber was measured. Thermal conductivity was an important property of ceramic-based metamaterials. Good thermal conductivity was beneficial to heat absorption and heat dissipation of ceramic based metamaterials. In the final experiments, the thermal response current of metamaterial samples was measured by using the Thermal Pulse Method (TPM) method [37]. Since the area of the hot plate was much larger than the area of the metamaterial sample, the diffusion of heat in the metamaterial was close to the one-dimensional heat conduction principle. Therefore, in TPM measurement, the thermal response current of the standard substrate surface can be obtained by extracting the induced electric field and differentiating it. A hot plate and a standard metal substrate were separated by the ceramic-based metamaterial samples, as shown in figure 11. The hot plate was used the C-MAG HP10. The standard metal substrate was a 2 cm thick aluminum plate. A voltage DC supply (200 THzV) was used to amplify the thermal response current of the surface on the standard substrate, as shown in figure 11. During the measurement, the temperature of the hot plate was set to 600 K. Heat was excited from the hot plate and passes  through the ceramic-based metamaterial absorber to the upper surface of the standard metal substrate. Heat reaching the surface of the standard substrate causes a slight deformation which excited a thermal response current. The thermal response current was extracted and enhanced by an amplifying circuit, as shown in figure 11. The current amplifier exhibited a bandwidth of 250 kHz and a current limiting resistance of close to 350 MΩ. The oscilloscope (TBS2000B) was also used to display it. This oscilloscope had a bandwidth of 70 MHz − 200 MHz. At the same time, in order to reduce the influence of microbubbles on heat conduction during the measurement process, the gap between the hot plate and the metamaterial sample, as well as between the metamaterial sample and the standard substrate were filled with dimethicone oil to achieve higher heat conduction efficiency. According to the measurement principle shown in figure 11, the thermal response resonance current, thermal conductivity, and thermal resistance of the metamaterial sample can be obtained. According to TPM method, assuming that the total heat energy excited by the hot plate was Q , hot plate -then the heat energy Q sample obtained by the metamaterial sample was:

= +
Here, E(z) was the induced electric field intensity of the surface of a standard metal substrate, d was the thermal contact area between metamaterial and hot plate. d was the thickness of the metamaterial sample, a z was the thermal expansion coefficien, a e was the temperature coefficient of permittivity. During the measurement, a DC voltage was applied to the metamaterial sample and the standard substrate, and an induced electric field was obtained on the surface of the standard substrate. Then, because the thermal resonance current excited by the thermal effect on the surface of the standard substrate was strengthened, equation (5) was rewritten as: Meanwhile, the thermal resistance coefficients of the metamaterial sample can also be obtained synchronously: Here, T was the measured temperature, k sample was the thermal conductivity of the metamaterial sample, t was the measured time, k sample was the coordinate of the z axis, and the coordinate origin z = 0 was located on the surface of the standard substrate. The thermal response currents of metamaterial absorbent based on different ceramics (SiC, ZrSiO 4 , TmFeO 3 , and ZrSnTiO) were shown in figure 12(a). Meanwhile, the calculation results of thermal response current were shown in figure 12(b). The measurement error of thermal response current was 0.002A * 10 −8 , the measurement error of thermal resistance was 0.001 m 2* K/W, and the measurement error of heat conductivity was 0.002 m 2 s −1 . Based on the TPM method, the thermal response resistance and thermal conductivity were extracted based on the thermal response current that was obtained. The measured thermal resistance and conductivity were shown in figure 13. The thermal response current of the metamaterial absorber based on the daily ceramic substrate (SiC) was reached its peak within 2.24 s, as shown in figure 12(a). When the measurement time was greater than 2.24 s, the thermal response current was basically stable, about 1.67 A * 10 −8 , as shown in figure 12(a). This indicated that it taked 2.24 s for heat to pass through the daily ceramic metamaterial absorber and reached the surface of the standard metal substrate. Then a stable heat transport state was formed. The elapsed time was determined by the thermal conductivity of the ceramic-based metamaterial absorber. The higher the thermal conductivity of the metamaterial absorber, the less time it taked for the thermal response current to reach its peak. Similarly, the thermal response currents of three other ceramic based metamaterial absorbers were also measured, as shown in figure 12(a). For example, the metamaterial absorber based on ZrSiO 4 ceramics takes 3.03 s for the thermal response current to peak, and the thermal response current was stable at 1.58 A * 10 −8 . For the TmFeO 3 ceramic based metamaterial absorber, the time required for the thermal response current to reach the peak value was 1.71 s, and the stable value was 1.86 A * 10 −8 . Finally, for the metamaterial absorber based on ZrSnTiO ceramics, the time required for the thermal response current to reach the peak value was 2.27 s, and the stable value was 1.72 A * 10 −8 , as shown in figure 12(a). Obviously, the thermal conductivity of metamaterial absorbers based on SiC ceramics was similar to that based on ZrSnTiO ceramics. Meanwhile, the simulated thermal response currents of the four ceramic based metamaterial absorbers also exhibited similar resonant behavior, as shown in figure 12(b).
In order to more intuitively reveal the thermal conductivity of the ceramic-based metamaterial absorber, the thermal conductivity and thermal resistance were measured and calculated based on the thermal response current, as shown in figure 13. For these ceramic-based metamaterials (SiC, ZrSiO 4 , TmFeO 3 , and ZrSnTiO), the measured results of heat conductivities were: 38.55 W/(m * K), 35.9 W/(m * K), 41.4 W/(m * K), and 39.5 W/ (m * K), respectively, as shown in figure 13(a). The thermal resistance measurement results of the four ceramic metamaterials were: 11.48 m 2* K/W, 11.1 m 2* K/W, 11.7 m 2* K/W, and 11.6 m 2* K/W, as shown in figure 13(b). The simulation results of the thermal conductivities and thermal resistances were similar to the measured results. Compared with the other three ceramics, TmFeO 3 had higher thermal resistance, and its thermal conductivity was the lowest, as shown in figure 13. Due to the thermal resonance characteristics (high thermal resistance and low heat conductivity) of TmFeO 3 , more energy was lost when heat penetrates the ceramic-based metamaterial. This results in less heat reaching the surface of the standard metal substrate, weakening the peak thermal response current and causing the thermal response current to take longer to reach a stable state, as shown in figure 12.

Conclusion
In this paper, a high temperature resistant metamaterial absorber based on daily ceramics was measured and verified. The absorption band was strengthened by increasing the thickness of the daily ceramic substrate or the diameter of the disk array. The absorption properties (average absorption rate and bandwidth) of the metamaterial were not sensitive to the preparation technologies (Chemical vapor deposition, Microwave induced synthesis, Sol-gel method, Carbothermal reduction method). Based on different dielectric properties, the average absorption of the metamaterial absorbers based on domestic ceramic substrates (SiC, ZrSiO 4 , TmFeO 3 , and ZrSnTiO) were: 0.861, 0.776, 0.908, and 0.857. The measured results of heat conductivities based on four types of daily ceramic substrate were: 38.55 W/(m * K), 35.9 W/(m * K), 41.4 W/(m * K), and 39.5 W/(m * K). The measured thermal resistances were: 11.48 m 2* K/W, 11.1 m 2* K/W, 11.7 m 2* K/W, and 11.6 m 2* K/W. The measurement results show that the type of ceramic substrate has an important effect on the thermal conductivity of the metamaterial absorber.