Enhancement of electric field of bowtie nanoantenna

Abstract

A nanoantenna is designed to transform high frequency into energy. The proposed antenna is made of aluminuim. are shaped with a pair of nanoparticles brought in close nearness. Antennas separated by small gaps printed on a Si layer, which is designed as a flat-edge bowtie, with a ground plane at the under most of the substrate with a feeding putting in the gap of the bowtie antenna. The proposed antenna is designed using 3D-electromagnetic solver (CST) programs and analysed for the optimisation of metal thickness, gap size, and geometrical length. Simulations are conducted to investigate the behaviour of the nanoantenna illuminated by the linearly polarized plane wave. The nanoantenna parameters such as substrate thickness, feeding size, feeding type, and feeding material were changed to select the most efficient nanoantenna with a large directivity in our reaserch find the nanoantenna make a high electric field enhancement in their gap region. This specialty can be employed for SERS or biosensing to improve the detection limit and measure the presence of single molecules. For this, it is necessary to create antennas with enough small gaps, to be capable to recompense for the defects created during the fabrication process and reach antenna characteristics that are close to the ones presage by simulations. The numerical simulations are studied to improve the best E-field of the antenna within the 250–700 THz frequency range. The proposed antenna offers multiple-resonance frequencies and good return loss in the frequency band of 310 THz, as well as an output electric field of 5.48 v/m to 7.8 v/m. Upon changing the type of feeding in the gap (without feeding, air feeding, dielectric silicon, or feeding), and we find that when using the air between the gap, the S-parameter is (-12.9) dB at the resonance frequency of (531.3) THz and the directivity is 7.41 dB at 666 THz incident frequency.