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A high gain and high aperture efficiency metamaterial (MTM) antenna is applied to a solar telescope in this paper. First, a portable solar telescope including the MTM antenna and a receiving system is presented. Next, the theory of the MTM antenna is proposed and analyzed based on the ray-tracing model. The designed MTM antenna is composed of a dual circularly polarized Fabry–Pérot resonant antenna (FPRA) and four phase correction metasurfaces (PCMs). The proposed PCMs act as the reflection surface and the phase correction surface at the same time. Every PCM consists of 2 × 18 optimized artificial magnetic conductor (AMC) units. To solve the parallel incidence and narrow bandwidth problems of AMC units, a nonuniform partially reflective surface is designed. Compared with traditional FPRA, the proposed MTM antenna has an increase in peak gain of 37.5% and an aperture efficiency of 11.4%. Then, a receiving system composed of the receiver, equatorial mount, data acquisition module, and display module is presented for solar radio signal processing. Finally, the designed MTM antenna and solar telescope are simulated and measured. A good agreement between the simulation and measurement is observed and can be used to verify this design. [ABSTRACT FROM AUTHOR]

In this paper, a 30 dB broadband microstrip directional coupler is designed by using a discrete coding type coupling structure with a co‐simulation technique. Combined with the proposed hybrid binary particle swarm genetic optimization algorithm (HBPSGOA) and the carefully designed fitness function, the discrete coding type structure can provide satisfactory flexibility and excellent performance. For a fixed design space, the discrete space can firstly be encoded and mapped to the corresponding coding matrix, and then the optimal coding matrix searched by HBPSGOA will be used to design a broadband coupler with high directivity. The effectiveness of the proposed HBPSGOA, binary particle swarm algorithm (BPSO), and genetic algorithm (GA) to design a discrete coding type coupler is tested. Experimental results prove that the HBPSGOA proposed in this paper has higher optimization efficiency. For the 30 dB broadband microstrip directional coupler designed in this paper, the center frequency is at 2 GHz and the fractional bandwidth is 39.4%. The minimum directivity of the designed coupler is 20 dB in the operating band and the maximum directivity is 39.3 dB at 1.9 GHz. In addition, the reason why the coupler can work in a wideband is investigated. [ABSTRACT FROM AUTHOR]

With the deterioration of the global climate, there is consensus that the environment and economy must develop in coordination. Effective environmental regulation (ER) is an important incentive of environmental protection, and there is a clear interaction mechanism between it and the economic growth quality (EGQ). In order to explore the intrinsic link between ER and EGQ, this study establishes a comprehensive evaluation index system from the research perspective of the coupling coordination degree (CCD). Based on the panel data of 30 provincial administrative regions in mainland China (excluding Tibet), from 2004 to 2017, the entropy method, coupling coordination model, and spatial econometric model are used to explore the CCD and the factors influencing the CCD of ER and EGQ. The key findings of this study were as follows: (1) The CCD of ER and EGQ system showed an upward trend in the fluctuation from 2004 to 2017. (2) In 2017, Beijing showed good coordination, Yunnan and Qinghai showed primary coordination, and the rest of the provinces showed moderate coordination. (3) The CCD of different regions in China is uneven. (4) Per capita GDP, per capita FDI, ER intensity, and industrial structure adjustment have promoting effects on the CCD, while per capita investment in fixed assets and environmental pressure have inhibiting effects on the CCD. Our conclusions are significant for promoting the integrated development of regional economy and ecological civilization, and provide a theoretical reference for other countries and regions to explore the relationship between ER and EGQ. [ABSTRACT FROM AUTHOR]