In modern communication systems, ultra-wideband (UWB) technology has garnered substantial attention due to its superior attributes compared to traditional narrowband communication systems. Over the past decade, UWB technology has also found applications in microwave-based imaging systems. This study introduces a simple planar coplanar waveguide-fed circular shape arc slot antenna designed specifically for biomedicine and microwave medical imaging applications. The proposed design is implemented on a 1.6-mm-thick FR4 substrate with a relative permittivity of 4.4 and a loss tangent of 0.0009. The antenna has physical dimensions of 26 mm × 29 mm and achieves an impressive bandwidth of 16.6 GHz, spanning 2.4 to 19 GHz. It exhibits a peak gain of 2.5 dBi and consistent omnidirectional radiation characteristics. Thorough temporal analysis validates the antenna's performance within acceptable limits, which is further affirmed through practical fabrication and testing, demonstrating strong agreement with simulation results.

This article introduces a wide-band MIMO antenna system with eight elements specifically designed for future handheld devices. The antenna is integrated into a 150 x 75 mm2 main board with a DGS antenna beneath it, connected to feed lines, and etched onto the ground plane. Covering two distinct 5G bands from 3 GHz to 3.6 GHz and from 3.6 GHz to 3.9 GHz, with 900 MHz impedance bandwidths, this antenna enables efficient data transmission and reception across these crucial frequency ranges. The system exhibits pattern and spatial diversity characteristics, achieving an overall efficiency of 40%-60% and a peak gain of 5.3 dBi, ensuring robust signal strength and isolation exceeding 10 dB among radiating elements. Furthermore, the antenna excels in key MIMO parameters, with an envelope correlation coefficient (ECC) below 0.19, well within the industry standard of less than 0.5, and it delivers more than 9.99 dB of diversity gain. Furthermore, Channel capacity Loss (CCL), Mean Effective Gain (MEG) and Total Active Reflection Co-efficient (TARC) across the entire operational band ensure good performance, promising enhanced diversity performance, superior data throughput, and heightened signal reliability. are The SAR analysis conducted yielded positive results within the human vicinity. The measurements obtained from the prototype matched well with simulations and through measurements obtained the proposed MIMO system can be termed as a potential candidate for future 5G Mobile Phones.

This paper discusses the alternating-current (AC) and direct-current (DC) characteristics of Trigate FinFETs. A modified non linear DC model is proposed to predict I-V characteristics with effect of an efficient technique for the extraction of AC small signal parameters. The extraction of small signal parameters using S-measurements can be developed on advance design system (ADS) software which is based on the electrical behavior of the device. It examines the electrical response as it depends on bias voltages and the extrinsic and intrinsic parameters of Si FinFETs. The approaches discussed here are valid over a range of frequency starting from few Hz up to several tens of GHz. In this paper equivalent circuit procedure has been adopted to compute device AC parameters based on its measured AC response. The characteristics were then simulated by developing a Matlab code based on particle swam optimization (PSO) technique and compared with technology computer aided design (TCAD) data. The results shows that the good agreement are achieved between simulated and TCAD data.

In this article, a compact four-port MIMO antenna system resonating from 4.7–5.1 GHz on −6 dB criteria is discussed. The proposed antennas are arranged in a perpendicular manner providing diversity with good isolation characteristics. The proposed antenna was fabricated and designed on a commercially available low-cost FR-4 substrate with a relative permittivity of 4.4. The total size of the antenna is 40 × 40 mm2, and a minimum isolation of 25 dB was observed at most nearby resonating elements. The proposed antenna was fabricated and tested at an in-house facility, and the measured results agree well with the simulations. The MIMO antenna characteristics, such as the envelope correlation coefficient (ECC) among any two radiating elements, have been found to be less than 0.1, and the diversity gain (DG) value evaluated showed that the proposed antenna is well designed. Furthermore, the SAR analysis showed that the desired antenna system is safe for users, with a value of 0.94 W/Kg. The channel capacity (cc) was found to be 18.7 bps/Hz, approximately 2.7 times more than SISO systems. Through its robust and reliable performance and its peak gain of 2.8 dBi, the proposed compact antenna is a good candidate for future 5G devices.

In this work, a low-cost, deployable, integratable, and easy-to-fabricate multiple-input multiple-output (MIMO) Kirigami antenna is proposed for sub-6 GHz applications. The proposed MIMO antenna is inspired by Kirigami art, which consists of four radiating and parasitic elements. The radiating and parasitic elements are composed of a rectangular stub. These elements are placed in such a way that they can provide polarization diversity. The proposed MIMO antenna is designed and fabricated using a soft printed board material called flexible copper-clad laminate (FCCL). It is observed from the results that the proposed MIMO antenna resonates in the 2.5 GHz frequency band, with a 10 dB reflection coefficient bandwidth of 860 MHz ranging from 2.19 to 3.05 GHz. It is worthwhile to mention that the isolation between adjacent radiating elements is higher than 15 dB. In addition, the peak realized gain of the MIMO antenna is around 11 dBi, and the total efficiency is more than 90% within the band of interest. Moreover, the envelope correlation coefficient (ECC) is noted to be less than 0.003, and the channel capacity is ≥17 bps/Hz. To verify the simulated results, a prototype was fabricated, and excellent agreement between the measured and computed results was observed. By observing the performance attributes of the proposed design, it can be said that there are many applications in which this antenna can be adopted. Because of its low profile, it can be used in 5G small-cell mobile MIMO base stations, autonomous light mobility vehicles, and other applications.

Nowadays, more attention has been given into ultrawideband by dint of its extraordinary features over narrowband communication systems. This study presents a novel compact with tilted square frames shape antenna with partial ground plane. The proposed antenna is printed on commercially available Fr4 substrate with relative thickness of 1.6 mm. The antenna has compact dimensions of 14 × 18 mm2 with bandwidth ranging from 3.3 to 11.5 GHz. The peak gain obtained is 1.4 dBi with omnidirectional radiation characteristics throughout the entire bandwidth. The proposed antenna is fabricated, and the developed prototype measured results, which well agree with simulated results. With the performance parameters obtained and the well agreed measured results, the proposed antenna is well suitable for Wi-Fi, ISM, and UWB applications.

A scalable small signal model for RF CMOS transistor is presented in this paper. The model consists of interconnects, substrate network, and intrinsic parameters. The proposed scaling rules characterize the transistors with different numbers of fingers. Based on this, the bias dependency, linear, and nonlinear behavior of all parasitic components are evaluated. A set of scalable RF CMOS models are validated by fabricating in the 90‐nm CMOS process, with gate width of 650 × 8 nm, 650 × 16 nm, 650 × 32 nm, and 650 × 64 nm, respectively. Further, the validity of the proposed model is carried out by comparing the calculated and measured results under different bias conditions up to 66 GHz. The root mean square errors calculated between measured and calculated results are within 0.0110 for S 11 , 0.0036 for S 12 , 0.0388 for S 21 , and 0.0106 for S 22 , respectively. A fairly good agreement predicts that the model is simple, scalable, and conducive for millimeter‐wave circuits.

This paper presents a high linearity wide band low noise amplifier for 5G front-end receiver systems. The proposed LNA has two common source stages cascade in current reused topology. An inductor based wideband inter-stage matching network acts to share the bias current, improve the gain and noise figure performance. Besides a series RC network is connected to second stage gate terminal to improve the stability significantly and reduce the return loss. The design of this LNA is demonstrated in 0.5μm GaAs pHEMT process. According to post-layout simulation results, a flat gain and noise figure of 16 dB and 1 dB are achieved respectively for a wide bandwidth of 1.5-5.5 GHz. A 3-dB bandwidth of 6.0 GHz, output P 1dB of +20 dBm and output IP3 of +40 dBm are achieved. The LNA chip size along pads is only 0.64 mm 2 .

A CMOS small signal model suitable for millimeter wave applications and its parameter extraction has been proposed. In the model, multi bias nonlinear behavior of S11 and S22 are characterized. In addition, the effects of intrinsic and extrinsic parameters are scrutinized. To verify the validity, a 32-finger MOSFET in 90-nm CMOS process is fabricated and examined under multi bias conditions. An excellent agreement between measured and calculated have been accomplished which shows that the performance of transistor up to 66 GHz can accurately be characterized. An error between measured and model is calculated under zero bias, saturation bias and triode bias are within 0.0109 for S11, 0.0169 for S12, 0.0304 for S21 and 0.0130 for S 22 , respectively. Furthermore, an error for 30-bias points are calculated to validate its accuracy.