A novel single‐fed dual‐band circular‐polarization (CP) reconfigurable liquid dielectric resonator antenna (LDRA) using 3D printing technology is proposed in this article. With the quasi‐TE111 and ‐TE113 modes of the rectangular LDRA excited, a dual‐band design is achieved. To realize the CP reconfigurability, a combined container, holding the fluidic dielectric (Ethyl acetate, ε
r = 6.6), is fabricated by 3D printing technology. Therefore, the CP can be switched between two different states: (1) left hand CP (LHCP), when the right oblique container is full of the liquid solution; (2) right hand CP (RHCP), when the liquid solution is transferred into the left oblique one. Measured results demonstrate that the proposed antenna can achieve the CP reconfigurability in dual band, with the wide bandwidths (|S11| < −10 dB and AR < 3 dB) of 10.4% (1.55‐1.72 GHz) and 9.7% (2.29‐2.52 GHz), which cover GPS and WLAN bands.
Over 40 years ago, primary health care (PHC) was defined in the Alma-Ata Declaration as a critical component of the health care system to address the basic health demand of the people. In China, the Government attaches great importance to health care at the primary level. After the launch of the historical Reform of the Medical and Health Care System in 2009, the PHC system in China has witnessed major progress and breakthroughs, especially in its steadily increased capacity, continuously improved accessibility, and betterment in equality. In this review, we summarized published literatures and official policies, synthesized data from the electronic registration information system of the National Health Commission, national statistical reports, and yearbooks in health care. The review is intended to describe the systematic development of PHC in China in the last decade. The main results include: the solid national policy foundation, increasing number of PHC institutions and workforce, better training of PHC professionals, major achievements in primary health indicators, government financial support to PHC institutions, improved PHC budgeting and insurance coverage, and the advancement of supporting technologies. Challenges and prospects are also discussed.
To reduce the mutual coupling between tightly spaced dual‐band patch antennas, a new waveguided metamaterial (WG‐MTM) is proposed in this research. The present WG‐MTM structure is composed of spiral periodic structures, which are etched on the ground. By loading the WG‐MTM between two dual‐band patch antennas, electric resonance and magnetic resonance are, respectively, generated in the lower and higher bands, which successfully suppress couplings between two antenna elements. According to simulated and measured results, when the edge‐to‐edge distance of two patch antennas with MTM is approximately 0.11λ0 (high‐band wavelength in the vacuum), the present structure can achieve about 7 dB and 5 dB reductions of mutual coupling in the lower and higher frequency bands, respectively.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.