High-Gain Metasurface in Polyimide On-Chip Antenna Based on CRLH-TL for Sub-Terahertz Integrated Circuits

Abstract

this paper presents a novel on-chip antenna using standard cMoS-technology based on metasurface implemented on two-layers polyimide substrates with a thickness of 500 μm. the aluminium groundplane with thickness of 3 μm is sandwiched between the two-layers. concentric dielectric-rings are etched in the ground-plane under the radiation patches implemented on the top-layer. the radiation patches comprise concentric metal-rings that are arranged in a 3 × 3 matrix. The antennas are excited by coupling electromagnetic energy through the gaps of the concentric dielectric-rings in the groundplane using a microstrip feedline created on the bottom polyimide-layer. the open-ended feedline is split in three-branches that are aligned under the radiation elements to couple the maximum energy. in this structure, the concentric metal-rings essentially act as series left-handed capacitances C L that extend the effective aperture area of the antenna without affecting its dimensions, and the concentric dielectric rings etched in the ground-plane act as shunt left-handed inductors L L , which suppress the surface-waves and reduce the substrates losses that leads to improved bandwidth and radiation properties. The overall structure behaves like a metasurface that is shown to exhibit a very large bandwidth of 0.350-0.385 THz with an average radiation gain and efficiency of 8.15dBi and 65.71%, respectively. It has dimensions of 6 × 6 × 1 mm 3 that makes it suitable for on-chip implementation.Antenna is the key component to enable wireless communication however their physical size is a function of the operating frequency. Applications of on-chip antennas is therefore limited to high-frequencies due to the large size of antenna at lower frequencies. Off chip antennas however offer the benefit of radiation efficiency as they can be implemented on low-loss dielectric substrates 1-6 ..Currently, antennas for front-end transceivers can be realised using three different methods, which include: (i) Antenna-in-Package (AiP), where the antenna is embedded in the IC's packaging; (ii) Antenna-on-Chip (AoC), where the antenna is realized on substrate; and (iii) this is a hybrid of AoC and AiP, where the radiating element is realized off-chip. Wire bonding and flip chip are the two commonly used interconnections techniques employed in AiP to connect the die and the antenna 7 . These types of interconnects are highly lossy at high frequencies due to impedance mismatch. The only viable solution to overcome this loss is by using on-chip antenna, which should significantly reduce the manufacturing cost of system-on-chip (SoC).The development of a truly efficient cost effective on-chip antenna is a challenging endeavour. The main challenges are attributed to (1) low resistivity of dielectric substrates, which is approximately 10 ohm-cm, contributes to substrate loss of 85% whereas metallization loss is only 15%; (2) high permittivity substrate confines most of the electromagnetic energy in the substrate rather than being radiated into free-space, which ...

Performance-Issues-Mitigation-Techniques for On-Chip-Antennas – Recent Developments in RF, MM-Wave, and Thz Bands With Future Directions

“…A limited such AoC designs have also been reported in THz band. In [134], a metasurface acting as an AMC based performance enhancement method is utilized for a 3 × 3 THz AoC array. The AoC arrays in [139] and [140] have also employed the performance enhancement methods.…”

“…The antenna designers and researchers can use these observations to optimize the performance of their AMC-based AoC accordingly. (b) Metasurface behaving as an AMC: In [134], the authors have proposed a high gain, 500 µm Polyimide substrate based metasurface structure, which behaves as an AMC for a 0.350 THz -0.385 THz AoC. The AMC like behaving metasurface structure is implemented by a 2-D composite left/right-handed metamaterial transmission line.…”

Radiation performance enhancement of an ultra wide band antenna using metamaterial band-pass filter

“…But the major involvement of metamaterials is in antenna structure to improve its functional parameters. Authors in [8,9] suggest a composite right left-handed (CRLH) metamaterial to beam scanning of a leaky wave antenna. Also, for UWB antenna many metamaterial configurations are proposed to [10,11], to enhance bandwidth [12,13] and to preserve compactness aspect of the hole structure [14,15].…”

Fully planar frequency independent square Archimedean spiral antenna with impedance transformer for ground penetrating radars

“…The approach of using monofilar Archimedean spiral and rectangular slots to design an antenna for on-chip applications based on metamaterial transmission-lines is proposed in. 29,30 Authors in 31 describe a novel planar microstrip array antenna based on a simplified composite right/left-handed transmission line for application in circularly polarized synthetic aperture radar systems. A novel technique to enhance the aperture of planar composite right/left-handed metamaterial antennas with minimal impact on the antenna's size is reported in 32 which is consists of vertically stacked composite right/left-handed unitcells comprising of a patch and meandered lines.…”