Low-index-metamaterial for gain enhancement of planar terahertz antenna

Abstract

We theoretically present a high gain planar antenna at terahertz (THz) frequencies by combing a conventional log-periodic antenna (LPA) with a low-index-metamaterial (LIM, |n| < 1). The LIM is realized by properly designing a fishnet metamaterial using full-wave finite-element simulation. Owing to the impedance matching, the LIM can be placed seamlessly on the substrate of the LPA without noticeable reflection. The effectiveness of using LIM for antenna gain enhancement is confirmed by comparing the antenna performance with and without LIM, where significantly improved half-power beam-width (3-dB beam-width) and more than 4 dB gain enhancement are seen within a certain frequency range. The presented LIM-enhanced planar THz antenna is compact, flat, low profile, and high gain, which has extensive applications in THz systems, including communications, radar, and spectroscopy.

Terahertz transmission through rings of quantum dots-nanogap

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“…Furthermore, the introduction of absorptive bio=chemical molecules such as DNA 15) into the low index medium of the wave-guide enormously affects the propagating modes and transmitted electric field. 17) Recently, results regarding fabrication or mostly theoretical proposals of negative, 18,19) near zero, [20][21][22][23] low, 16,24,25) and extremely high 26) mode index metamaterials have been published.…”

Polarization-Independent and Angle-Insensitive Metamaterial Absorber Using 90-Degree-Rotated Split-Ring Resonators

“…Over the past decade, a large number of metamaterials have been demonstrated at the desired regimes of electromagnetic spectrum from microwave, terahertz (THz), infrared to visible frequencies [3][4][5][6]. As metamaterials research continues to mature, they have inspired a vast amount of electromagnetic devices such as invisibility cloaks [7,8], perfect lens [9], and novel types of circuits and antennas [10][11][12][13][14]. One of the most promising applications of metamaterials is the absorption of electromagnetic waves, known as metamaterial absorbers (MAs) [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29].…”

A new miniaturized negative-index meta-atom for tri-band applications

“…However, metamaterials were broadly utilized to develop many antennas. In [6][7][8], the performance of the antennas was improved by embedding metamaterials.…”