A 3-bit beam steerable antenna array based on a microstrip line is designed and implemented at 28 GHz for millimetre-wave application. The antenna consists of an 8-element tightly stacked aperture and a switchable feeding network. The latter consists of a one-to-eight-way uniform microstrip corporatefed power divider and is separated from the radiating element by a ground plane. To achieve coupled feeding, the ground plane has two rows of slots under each antenna element. A switching mechanism was implemented on the microstrip line to realize 3-bit periodic phase shifting for beamsteering. By sampling 8 feed points with a separation distance of λ/8, a 3-bit phase shifter was constructed with phases of 0and −315 • . Continuous beamsteering was achieved from −50 • to +50 • by switching eight different sampling states, both in numerical calculation and in simulation. The design was verified by fabricating and testing three different prototype configurations at 28 GHz. The measured prototypes showed an excellent match with the simulation results. Notably, the maximum measured gain was found to be 13.44 dBi with a gain threshold of 10 dBi within the steering range (viz. 100 • ).INDEX TERMS Reconfigurable, millimeter-wave antenna, aperture-fed antenna, 3-bit-phase shifter, beamsteering.

A new layered ternary chalcogenide CuZnTe2 and its effect due to potassium (K) intercalation have been investigated using ab-initio method under the framework of density functional theory (DFT). Here, we report the structural, electronic and elastic properties of both proposed parent compound CuZnTe2 and intercalated KCuZnTe2. The electronic band structures and the density of states (DOS) of both these chalcogenides have also been studied. The parent compound demonstrates p-type conductivity with the energy band gap of 0.7 eV but surprisingly, the increase of energy gap (1.5 eV) is found in the intercalated KCuZnTe2, a direct-transition type semiconductor. The optical absorption result in KCuZnTe2 also shows the identical value of gap energy calculated by Wood-Tauc theory. The density of states (DOS) in the valence band for both compounds is dominated by the partial contribution of Cu/Zn 3d and Te 5p orbitals but the prime contribution of Cu/Zn 4s and Te 5s mainly in the conduction band DOS. The DOS value at around Fermi level in these chalcogenides is indicating the degeneracy behavior of a semiconductor. Both compounds are mechanically stable and also malleable. We also calculated the thermal properties in the intercalated KCuZnTe2 using quasi-harmonic Debye model. The observed values of Debye temperature, specific heat capacities and volume expansion coefficient using this model is almost consistent with the estimated values given in theory.

ObjectivesThe aims are to explore the factors influencing Bangladeshi patients' decision-making process and their satisfaction level toward medical tourism in India.MethodsThe study used a quantitative research approach with a cross-sectional survey. Data were collected from the patients or their relatives (N = 388) who would have decided to travel to India for medical and treatment purposes at the Chittagong Indian visa center (IVAC). Data were collected using a structured, pre-tested, and facilitator-administered questionnaire, which mainly included the social demographic characteristics, health status, medical tourism information and medical tourism index. Hierarchical regression analysis was performed to explore the factors influencing their satisfaction level toward medical tourism in India.ResultsMore than three-fourths of the participants had visited India for self-treatment. Of the participants, 14% were cardiology patients, and 13% suffered from cancer. The relatives were the key source of information regarding medical tourism for more than one-fourth of the respondents. India's availability of well-experienced doctors, hospital/medical facilities with high standards, well-trained doctors, reputable doctors, and quality treatments and medical materials were top-ranked items. Regression results depict that facility and services appeared as the strongest factor (β = 0.24, t = 4.71, p < 0.001) followed by tourism destination factor (β = 0.16, t = 3.11, p = 0.002), medical tourism costs factor (β = 0.16, t = 3.24, p = 0.001) and country environment factor (β = 0.15, t = 2.69, p = 0.007).ConclusionsWe found that the factor related to facility and services is one of the strongest predictors in our models. Therefore, home countries must strengthen the health care providers' advanced professional training, including service attitudes. Moreover, it is important to lessen the language barrier, reduce the airfare for medical tourists, and make the treatment cost more affordable for patients.

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