The present work deals with the vibrational spectroscopic signature of the synephrine molecule and its radical in the gas phase. We have optimized synephrine and synephrine^- in the ground state. The optimization of the neutral and de-protonated synephrine has been performed at the B3LYP/6-31++G(d, p) level of theory. The comparison of vibrational frequencies of both the structures has also been made. Most of the vibrational frequencies are in good agreement with the experimental ones. The effect of hydrogen removal from the site of oxygen atom upon geometrical parameters and vibrational frequencies of synephrine has been reported. Subsequently, the different thermodynamical parameters calculated at room temperature for the synephrine and its radical have been discussed. Interestingly, the enthalpy of formation for the synephrine and deprotonated synephrine has been calculated. The NBO analysis has been performed to check the stability of the electronic structure of the radical form of the synephrine molecule. Also, the HOMO-LUMO energy gap infers that synephrine is more reactive in its radical form.

A miniaturized butterfly-shaped microstrip patch antenna is proposed for unlicensed millimeter wave band applications. The overall dimensions of the proposed antenna are (20 × 18 × 1.6) mm³ or (3.93 × 3.54 × 0.314)λ₀ ³ with rectangular defected ground structure, which is etched on the ground plane to improve its performances. This configuration achieved an ultra-wide bandwidth (UWB) of 7 GHz (26%) and 22 GHz (37.9%) with radiation efficiencies of 92% and 61%, covering the frequency range from 19.3–25.2 GHz to 48–70 GHz, respectively. The reflection coefficient of the antenna is −41.2 dB with a peak gain of 12.4 dBi at the 56.6 GHz and 10 dBi at 61.4 GHz resonating frequency. Further, the analysis of the proposed antenna is done by different feeding techniques like coaxial, inset feed, gap coupled, aperture coupled and proximity coupled. Considering the size, bandwidth and gain, the microstrip antenna is applicable for unlicensed 57–64 GHz wireless applications for the short-range and high-speed communications like WPAN, WLAN, Intelligent Transport System, Smart Automobiles and Gi-fi. All the simulation results have been performed on Ansys HFSS v.13.1. Proposed antenna has been fabricated on the PCB board.