Modeling and Analysis of Terahertz Graphene Switches for On-Wafer Coplanar Transmission Lines

Theofanopoulos, Panagiotis C.; Trichopoulos, Georgios C.

doi:10.1007/s10762-020-00711-4

“…Similarly to these tunable materials, other switching configurations could be exploited that have low losses (less than 1 dB) and are implemented with traditional solid-state technologies [28][29]. In the case of lossy switches (e.g., graphene [24]- [27]), the performance of the multi-bit configurations is expected to decline as preliminary results indicate [38], though this characterization extends the scope of this work.…”

Section: Discussionmentioning

confidence: 99%

“…In an implementation scenario, the integrated mmWave/THz SPST switches could be devised using solid-state technologies (e.g., GaAs) [29] and/or tunable 2D materials, including graphene, molybdenum disulfide, vanadium dioxide, etc. [27]. Typically, these sub-mmWave switches are implemented in a planar shunt configuration, utilizing coplanar waveguides (CPW), striplines, or slotlines to acquire optimum RF performance [27].…”

Section: B Single-bit Unit-cell Designmentioning

confidence: 99%

See 1 more Smart Citation

A Single-Switch-per-Bit Topology for mmWave and THz Reconfigurable Reflective Surfaces

Theofanopoulos¹

2021

Preprint

0

View full text Add to dashboard Cite

<div> <div> <div> <p>We present novel multi-bit unit-cell topologies for reconfigurable reflective surfaces –RRSs– (e.g., reflectarray antennas) with compact designs for millimeter-wave and terahertz (mmWave/THz) applications. Typically, mmWave/THz RRSs utilize one or multiple single-pole-single-throw (SPST) switches leading to single- or dual-bit modulated surfaces. These surfaces utilize the switches to manipulate the phase of the imping waves, beamforming the reflected waves to the desired direction. As such, RRSs are leveraged either for imaging or wireless communication applications, which typically require the formation of a single beam (no grating lobes) and high gains. The gain and quantization lobe levels of an RRS is strictly related to the number of phase bits utilized in the unit-cell. Explicitly, more phase bits lead to lower quantization errors and better maximum gain/aperture efficiency. However, increasing the number of phase bits requires more SPST switches integrated within the unit-cell, leading to complex designs with high RF losses. Herein, we present, for the first time, RRSs with up to 4 phase quantization bits (16 states) that maintain one switch-per-bit topology thus retaining a low-complexity design. The proposed RRSs is presented alongside a series of analytical and full-wave simulated results. </p> </div> </div> </div>

show abstract

“…In an implementation scenario, the integrated mmWave/THz SPST switches could be devised using solid-state technologies (e.g., GaAs) [29] and/or tunable 2D materials, including graphene, molybdenum disulfide, vanadium dioxide, etc. [27]. Typically, these sub-mmWave switches are implemented in a planar shunt configuration, utilizing coplanar waveguides (CPW), striplines, or slotlines to acquire optimum RF performance [27].…”

Section: B Single-bit Unit-cell Designmentioning

confidence: 99%

“…[27]. Typically, these sub-mmWave switches are implemented in a planar shunt configuration, utilizing coplanar waveguides (CPW), striplines, or slotlines to acquire optimum RF performance [27].…”

Section: B Single-bit Unit-cell Designmentioning

confidence: 99%

A Single-Switch-per-Bit Topology for mmWave and THz Reconfigurable Reflective Surfaces

Theofanopoulos¹

2021

Preprint

View full text Add to dashboard Cite

<div> <div> <div> <p>We present novel multi-bit unit-cell topologies for reconfigurable reflective surfaces –RRSs– (e.g., reflectarray antennas) with compact designs for millimeter-wave and terahertz (mmWave/THz) applications. Typically, mmWave/THz RRSs utilize one or multiple single-pole-single-throw (SPST) switches leading to single- or dual-bit modulated surfaces. These surfaces utilize the switches to manipulate the phase of the imping waves, beamforming the reflected waves to the desired direction. As such, RRSs are leveraged either for imaging or wireless communication applications, which typically require the formation of a single beam (no grating lobes) and high gains. The gain and quantization lobe levels of an RRS is strictly related to the number of phase bits utilized in the unit-cell. Explicitly, more phase bits lead to lower quantization errors and better maximum gain/aperture efficiency. However, increasing the number of phase bits requires more SPST switches integrated within the unit-cell, leading to complex designs with high RF losses. Herein, we present, for the first time, RRSs with up to 4 phase quantization bits (16 states) that maintain one switch-per-bit topology thus retaining a low-complexity design. The proposed RRSs is presented alongside a series of analytical and full-wave simulated results. </p> </div> </div> </div>

show abstract