Air-bridged Schottky diodes for dynamically tunable millimeter-wave metamaterial phase shifters

Vassos, Evangelos; Churm, James; Powell, Jeff R.; Viegas, Colin; Alderman, Byron; Feresidis, A.P.

doi:10.1038/s41598-021-85565-z

Cited by 15 publications

(3 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One or more switches can be used to switch paths that can be either P-I-N diodes, varactor diodes or MEMS switches [173] [174]. Schottky diode is used for high-speed switching and varactor diodes provide fine-tuning of frequency within the required band [175]. Mechanical reconfiguration is achieved by conductive fluid antennas, dielectric fluid antennas, gearing and origami-based antennas [172].…”

Section: ) Frequency Reconfigurationmentioning

confidence: 99%

Next Generation Cognition-Aware Hearing Aid Devices With Microwave Sensors: Opportunities and Challenges

et al. 2022

View full text Add to dashboard Cite

The strong association between hearing loss and cognitive decline has developed into a major health challenge that calls for early detection, diagnosis and prevention. Hearing loss usually results in severe health implications that include loss of mobility, communication problems and cognitive decline. This study provides an overview of the effects of hearing loss on cognition and progressive neurological disorders with a discussion on the future scope of microwave portable technologies in care homes arrangement. Moreover, the efficacy of hearing aids in reversing cognitive decline and dementia has been investigated. The interconnection between hearing loss, cognitive load and neurodegeneration is also explored. Furthermore, this study looks into the prospects of using portable microwave sensors for the detection and monitoring of cognitive load. For early detection of dementia, this study proposes the integration of microwave sensors with hearing aid devices. Implications and design challenges of portable antenna systems for neurodegeneration detection have also been considered. Future improvement areas regarding robust analysis and diagnosis, system accuracy and security, user-centricity and device privacy for a broader clinical implementation are also discussed.

show abstract

Section: ) Frequency Reconfigurationmentioning

confidence: 99%

Next Generation Cognition-Aware Hearing Aid Devices With Microwave Sensors: Opportunities and Challenges

et al. 2022

View full text Add to dashboard Cite

show abstract

“…A key factor in the development of novel metasurfaces is the capability to dynamically control the impinging electromagnetic wave by applying a tuning method. Some of the tuning technologies that have been proposed are ferroelectric substrates, [25] liquid crystals, [26,27] phase change materials such as vanadium dioxide, [28] graphene, [3,29] diodes, [30][31][32][33] microelectromechanical systems (MEMS), [34,35] and more recently piezoelectric actuators (PEAs). [36,37] The choice of tuning method depends on the application and the required performance parameters.…”

Section: Introductionmentioning

confidence: 99%

Multifunction Tunable Piezoelectric‐Actuated Metasurface at Millimeter‐Waves

Vassos

Feresidis

2023

Advanced Photonics Research

Self Cite

View full text Add to dashboard Cite

Free space (also termed quasi‐optical) metasurfaces have recently been designed and proposed as new types of polarizers that allow polarization control of an impinging wave in ways that are not possible with conventional designs. However, existing methods for tunable metasurface polarizers are not able to fully control the polarization dynamically; additionally, at mm‐wave and submillimeter bands, they typically suffer from high losses, which are predominantly produced by the inherent limitations of the tuning elements or materials. An electromechanically tunable reﬂection polariser that has the ability to fully control the polarization of an impinging wave has been designed, fabricated, and experimentally tested in a frequency band centered at 57 GHz. The proposed technique utilizes a variable air cavity between a periodic metasurface array and a ground plane, controlled by a piezoelectric actuator. The periodic metasurface element consists of two slightly different cross‐shaped metallic elements arranged in a periodic triangular lattice. Full‐wave simulations are presented and experimentally validated with measurements. The proposed approach is scalable from microwave up to THz frequencies with low‐loss performance due to the nature of the tuning technology whereby the tuning element is not interfering with the electromagnetic waves in the structure.

show abstract

“…Tunable metamaterials can change their functionalities or performance in response to external stimuli [14]. Some of the common approaches to achieve tunability are utilizing diodes [15], micro-electromechanical systems (MEMS) [16], nano-electromechanical systems (NEMS) [17], graphene [18,19], hydrogel [20,21], temperature-responsive materials [22,23], and liquid crystals [24] in the design or changing the configuration of the resonators by applying mechanical deformations [25].…”

Section: Introductionmentioning

confidence: 99%

Effect of mechanical nonlinearity on the electromagnetic response of a microwave tunable metamaterial

Mahabadi¹,

Goudarzi²,

Fleury³

et al. 2022

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

Tunable metamaterials functionalities change in response to external stimuli. Mechanical deformation is known to be an efficient approach to tune the electromagnetic response of a deformable metamaterial. However, in the case of large mechanical deformations, which are usually required to fully exploit the potential of the tunable metamaterials, the linear elastic mechanical analysis is no longer suitable. Nevertheless, nonlinear mechanical analysis is missing in the studies of mechanically tunable metamaterials. In this paper, we study the importance of considering nonlinearity in mechanical behavior when analyzing the response of a deformable metamaterial and its effects on electromagnetic behavior. We consider a microwave metamaterial formed by copper four-cut split ring resonators on a Polydimethylsiloxane (PDMS) substrate. Applying both displacement and force stimuli, we show that when the deformation is large, more than 10 percent strain, the use of nonlinear analysis considering the geometrical and material nonlinearities is imperative. We further show that the discrepancies between the linear and nonlinear analyses appear in overestimating the stress, underestimating the tunability of the metamaterial responses, and mispredicting the negative permeability regions.

show abstract

Air-bridged Schottky diodes for dynamically tunable millimeter-wave metamaterial phase shifters

Cited by 15 publications

References 48 publications

Next Generation Cognition-Aware Hearing Aid Devices With Microwave Sensors: Opportunities and Challenges

Next Generation Cognition-Aware Hearing Aid Devices With Microwave Sensors: Opportunities and Challenges

Multifunction Tunable Piezoelectric‐Actuated Metasurface at Millimeter‐Waves

Effect of mechanical nonlinearity on the electromagnetic response of a microwave tunable metamaterial

Contact Info

Product

Resources

About