This paper reports the integration of S/Ka/D-band antennas in a low-temperature co-fired ceramic (LTCC) package. Operating at different bands, three types of antennas, including microstrip patch, grid array and step-profiled horn, are compactly assembled in the same substrate. For electromagnetic isolation, a specific layout and extra shielding structures, such as fences of metallic vias and air cavities, are designed to reduce the undesired coupling between antennas. In addition to the antennas, a cylindrical radome is introduced and closely attached to the surface of the LTCC substrate. Since the radome acts as a dielectric superstrate, its influence on radiation performance is also taken into consideration, especially for the D-band operation, where a ring-shaped cavity inside the radome is introduced to suppress the detrimental propagation of surface waves inside the radome and enhance the gain as a consequence of the dielectric loading effect. The measured results agree well with simulation. At three working frequencies of 3 GHz, 30.5 GHz and 120 GHz, the proposed triband antennas achieve broadside gains of 6.51 dBi, 9.74 dBi and 13.36 dBi with -10-dB fractional impedance bandwidths of 15.3%, 6.1% and 6.5%, respectively

Currently various types of aircraft booming and maturing, however, their long-time navigational capability should be improved urgently. This paper aims at studying laser power beaming, which includes the technology of high-efficient photoelectric conversion and APT(acquiring, pointing and tracking) technology, to provide power for flying UAV(unmanned aerial vehicles) and improve their flight endurance. The experiment of testing different types of solar cells under various conditions has been done to choose the solar cell which has the highest photoelectric conversion rate and find its most sensitive wavelength. In addition, the charge management module has been chose on the base of the characteristics of lithium batteries. Besides, a laser APT system was designed and set up, at the same time FSM (Fast Scan Mirror) control program and digital image processing program were used to control the system. The success of the indoor experiment of scan-tracking and charging for the moving UAV model via laser proves that this system is workable. And in this experiment, the photoelectric conversion rate of the whole system is up to 17.55%.

通过在石墨烯超表面设计周期性切条, 实现了基于石墨烯互补超表面的可调谐太赫兹吸波体. 通过改变外加电压来改变石墨烯的费米能级, 吸波体实现频率可调谐特性. 研究了石墨烯费米能级、结构尺寸对超材料吸波体吸收特性的影响, 并利用多重反射理论研究了其物理机理并且证明了模拟方法的可行性. 研究结果表明: 当石墨烯费米能级取0.6 eV, 基底厚度13 m, 石墨烯上切条长宽分别为2.9 m, 0.1 m 时, 吸波体在1.865 THz可以实现99.9%的完美吸收; 石墨烯费米能级从0.4 eV增大到0.9 eV, 吸波体共振频率从1.596 THz 蓝移到2.168 THz, 且伴随共振吸收率的改变, 吸收率在0.6 eV时达到最大; 通过改变费米能级实现的最大吸收率调制度达84.55%.

In recent years, the holographic antenna (HA) composed of impedance unit cells fed by surface waves has been developed rapidly. However, the cylindrical conformal holographic antenna (CCHA) is recently designed with planar unit cell impedance, which will result in beam deterioration and loss of gain and efficiency. Therefore, a way to calculate the impedance of curved unit cells is presented in this letter. Compared with the planar impedance calculation (PIC), the efficiency of the HA using the curved impedance calculation (CIC) is increased from 17.05% to 19.13% with the fixed deflection angle θ of 0° when the radius of the cylinder is 18 mm. An approximate calculation for the impedance of arbitrary cylindrical radius is proposed based on the PIC and CIC, which can achieve a more convenient calculation of impedance without significantly affecting performance. It has been shown that the efficiency of the HA using the approximate impedance calculation (AIC) is increased from 17.05% to 19.42% under the same conditions compared with the HA using the planar impedance calculation. The efficiency can also reach about 20% in the case of a small radius and angle less than 20 °, which is close to the efficiency of planar HA. The measured radiation efficiency is 21.48% with a small radius. The low efficiency of the CCHA has been improved.