Terahertz microstrip elevated stack antenna technology on GaN-on-low resistivity silicon substrates for TMIC

Abstract

Abstract-In this paper we demonstrate a THz microstrip stack antenna on GaN-on-low resistivity silicon substrates (ρ < 40 Ω.cm). To reduce losses caused by the substrate and to enhance performance of the integrated antenna at THz frequencies, the driven patch is shielded by silicon nitride and gold in addition to a layer of benzocyclobutene (BCB). A second circular patch is elevated in air using gold posts, making this design a stack configuration. The demonstrated antenna shows a measured resonance frequency in agreement with the modeling at 0.27 THz and a measured S11 as low as -18 dB was obtained. A directivity, gain and radiation efficiency of 8.3 dB, 3.4 dB, and 32% respectively was exhibited from the 3D EM model. To the authors' knowledge, this is the first demonstrated THz integrated microstrip stack antenna for TMIC (THz Monolithic Integrated Circuits) technology; the developed technology is suitable for high performance III-V material on low resistivity/high dielectric substrates.

Design and performance comparison of various terahertz microstrip antennas on GaN-on-low resistivity silicon substrates for TMIC

“…Heights of both dielectrics (single and stack antenna) are optimized to produce better antenna performance; stack dielectric is evaluated using air and BCB for better antenna performance. This study provides an extension of our previous work [15] and [16] where a single patch antenna and rectangular-circular stack antenna was demonstrated. From these studies, we showed that a rectangular-circular stack antenna gave an improved fabrication result at BCB and stack height of 5 flm with gain, directivity and radiation efficiency as high as 3.4 dB, 8.3 dB and 32% respectively.…”

“…The fabrication process of the proposed integrated antenna in this study is related to our previous work [16]. First, 200 nm ShNi4 was deposited onto GaN-on-LR Si using ICP-CVD deposition.…”

“…With this, TMIC also has an advantage of smaller chip size, lower system cost, and higher performance. Recent research shows that a 450 GHz cutoff frequency (fT) has been achieved Rectangular-circular antenna [16] using GaN high-electron-mobility-transistors (HEMTs) on semi-insulating (SI) SiC through the intensive progress in GaN HEMTs scaling technologies toward THz operation. Multiple frequencies of their fT can be obtained by implementing such devices using TMIC technology [6].…”

Passive components technology for THz-Monolithic Integrated Circuits (THz-MIC)

“…The fabrication process of the proposed technology in this study is related to our previous work [6]. First, 200 nm Si 3 Ni 4 was deposited onto GaN-on-LR Si substrate using ICP-CVD deposition on the mesa floor, where the transistor active region was etched away.…”