Semi-Flexible Diversified Circularly Polarized Millimeter-Wave MIMO Antenna for Wearable Biotechnologies

Tiwari, Rakesh N.; Kaim, Vikrant; Singh, Prabhakar; Khan, Taimoor; Kanaujia, Binod Kumar

doi:10.1109/tap.2023.3255507

Cited by 20 publications

(6 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hence, the comparison is performed with fully flexible and semi-flexible MIMO antennas. The proposed antenna has improved the directivity to broadside direction compared to [13], [21], [23]. The obtained SAR value is much less than all other designs in Table I.…”

Section: E Comparative Analysismentioning

confidence: 86%

“…The proposed structure has also improved the bandwidth compared to [22], which also used a reflective surface. The proposed antenna has slightly improved the isolation compared to [13], [21], [23]. The diversity parameters of the antenna are comparable with [13], [21], [22], and [23].…”

Section: E Comparative Analysismentioning

confidence: 88%

“…However, bandwidth at sub-6 GHz is restricted to <100 MHz [4]. The International Telecommunication Union (ITU) allocated a millimeter wave (mmWave) spectrum 30-300 GHz range to enhance the channel capacity, in that K-band (18)(19)(20)(21)(22)(23)(24)(25)(26)(27) and Ka-band are least prone to atmospheric conditions [5]. For wearable devices, the flexible antenna should satisfy the following criteria against conformal orientation: minimum operational bandwidth of 1 GHz, a specific absorption rate (SAR) < 1.6 W/kg (Federal Communication Commission (FCC) standard)/ < 2 W/kg (European Union (EU) standard), and stable bandwidth and radiation.…”

Section: Introductionmentioning

confidence: 99%

“…In [21], a two-element MIMO antenna is proposed for wearable applications where the radiator is a slotted circular patch with defected ground plane structure operating from 24-31 GHz. The slots in the radiator induced the effect of circular polarization.…”

Section: Introductionmentioning

confidence: 99%

“…The above literature shows that quite a few MIMO antenna designs exist for wearable applications. The MIMO antennas in [13], [21], [22], [23] have a large antenna profile. In [24] and [25], the design has poor impedance matching with high SAR.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Design and Measurement of a Compact Millimeter Wave Highly Flexible MIMO Antenna Loaded With Metamaterial Reflective Surface for Wearable Applications

Shariff,

Ali,

Mane

et al. 2024

IEEE Access

Self Cite

View full text Add to dashboard Cite

This article presents a flexible four-element MIMO antenna designed on a thin polyimide substrate to operate at 30.50 GHz for wearable applications. The antenna element structure is a combination of circular rings combined with T-shape stubs. The MIMO antenna isolation is enhanced through a novel decoupling structure consisting of a rectangular stub, four open-ended horizontal strip lines, and two vertical strip lines connecting the ground plane. It provides 22.5 dB isolation, even with conformal orientation. A metamaterial (MTM) reflective surface of 9 × 9 unit cells is designed and placed below the antenna to improve its radiation characteristics, bandwidth, gain, and specific absorption rate (SAR). The metamaterial unit cell provides a double negative property with a wide stop-band range of 26.27-36.49 GHz. With an MTM surface, the measured bandwidth is 25.2-33 GHz with a maximum broadside gain of 8.90 dBi. The resulting SAR is reduced from 1.71 W/kg to 0.86 W/kg with MTM surface. The MIMO antenna with MTM improves the bandwidth by 56%, gain by 32.5%, and radiation from bidirectional to broadside, compared to the MIMO antenna without MTM. Also, the antenna is measured and validated for diversity parameters such as Envelope correlation coefficient (ECC), Diversity gain (DG), Channel coefficient loss (CCL), Total active reflection coefficient (TARC), and Mean effective gain (MEG). The reduced SAR and improved antenna performance suggest the proposed MIMO antenna with an MTM reflective surface is suitable for on-body wearable applications in IoT devices, smart watches, headwear, and footwear devices.

show abstract

Section: E Comparative Analysismentioning

confidence: 86%