High-Bandwidth,Low-Power CMOS Transistor Based CAB for Field Programmable Analog Array

This article presents an integrated current mode configurable analog block(CAB)system for field-programmable analog array(FPAA).The proposed architecture is based on the complementary metal-oxide semiconductor(CMOS)transistor level design where MOSFET transistors operating in the saturation region are adopted.The proposed CAB architecture is designed to implement six of thewidely used current mode operations in analog processing systems:addition,subtraction,integration,multiplication,division,and pass operation.The functionality of the proposed CAB is demonstrated through these six operations,where each operation is chosen based on the user’s selection in the CAB interface system.The architecture of the CAB system proposes an optimized way of designing and integrating only three functional cells with the interface circuitry to achieve the six operations.Furthermore,optimized programming and digital tuning circuitry are implemented in the architecture to control and interface with the functional cells.Moreover,these designed programming and tuning circuitries play an essential role in optimizing the performance of the proposed design.Simulation of the proposed CMOS Transistor Based CAB system is carried out using Tanner EDA Tools in 0.35μm standard CMOS technology.The design uses a±1.5 V power supply and results in maximum 3 dB bandwidth of 34.9 MHz and an approximate size of 0.0537 mm2.This demonstrates the advantages of the design over the current state-of-the-art designs presented for comparison in this article.Consequently,the proposed design has a clear aspect of simplicity,low power consumption,and high bandwidth operation,which makes it a suitable candidate for mobile telecommunications applications.

Metamaterial-Based Compact Antenna with Defected Ground Structure for 5G and Beyond

In this paper,a unit cell of a single-negative metamaterial structure loaded with a meander line and defected ground structure(DGS)is investigated as the principle radiating element of an antenna.The unit cell antenna causes even or odd mode resonances similar to the unit cell structure depending on the orientation of the microstrip feed used to excite the unit cell.However,the orientation which gives low-frequency resonance is considered here.The unit cell antenna is then loaded with a meander line which is parallel to the split bearing side and connects the other two sides orthogonal to the split bearing side.This modified structure excites another mode of resonance at high frequency when a meander line defect is loaded on the metallic ground plane.Specific parameters of the meander line structure,the DGS shape,and the unit cell are optimized to place these two resonances at different frequencies with proper frequency intervals to enhance the bandwidth.Finally,the feed is placed in an offset position for better impedance matching without affecting the bandwidth The compact dimension of the antenna is 0.25λL×0.23λL×0.02λL,whereλL is the free space wavelength with respect to the center frequency of the impedance bandwidth.The proposed antenna is fabricated and measured.Experimental results reveal that the modified design gives monopole like radiation patterns which achieves a fractional operating bandwidth of 26.6%,from 3.26 to 4.26 GHz for|S11|<−10 dB and a pick gain of 1.26 dBi is realized.In addition,the simulated and measured crosspolarization levels are both less than−15 dB in the horizontal plane.

Decagonal C-Shaped CSRR Textile-Based Metamaterial for Microwave Applications

This paper introduces a decagonal C-shaped complementary splitring resonator(CSRR)textile-based metamaterial(MTM).The overall size of the proposed sub-wavelength MTM unit cell is 0.28λ0×0.255λ0 at 3 GHz.Its stopband behaviour was first studied prior analysing the negative index properties of the proposed MTM.It is worth noting that in this work a unique way the experiments were completed.For both simulations and measurements,the proposed MTM exhibited negative-permittivity and negative-refractive index characteristics with an average bandwidth of more than 3 GHz(considering 1.7 to 8.2 GHz as the measurements were carried out within this range).In simulations,the MTM exhibited negative-permittivity properties within the range of 1.7 to 7.52 GHz and 7.96 to 8.2 GHz;and negative-refractive index from 1.7 to 2.23 GHz and 2.33 to 5.09 GHz and 5.63 to 7.45 GHz.When measured from 1.7 to 8.2 GHz,negative-permittivity and negative-refractive index characteristics are exhibited throughout an average bandwidth of more than 3 GHz.Similarly,the transmission coefficient attained in simulations and measurements indicated about 3 GHz of bandwidth,from 1.7 to 3.88 GHz and from 6.68 to 7.4 GHz.The satisfactory agreement between simulations and experiments indicates the potential of the proposed MTM for microwave applications.

Wearable UWB Antenna-Based Bending and Wet Performances for Breast Cancer Detection

This paper proposed integrating the communication system on the garment,which can be utilized to detect breast cancer at an early stage by using an ultra-wideband(UWB)wearable antenna.Breast cancer is an abnormal cell that is located in the breast tissue.Early detection of breast cancer plays an important role,and it helps in the long term for all women.The proposed UWB wearable antenna successfully operates at 3.1-10.6 GHz under an acceptable reflection coefficient of−10 dB.The fabricated wearable antenna was made from Shieldit Super and felt both conductive and nonconductive wearable materials.Few measurement studies of bending angles have been carried out that covered 2°,4°,6°,8°,and 10°.In addition,the performance of UWB antennas in wet environments is studied in four stages:in water,instantly wet,nearly dry,and entirely dry.There is good agreement between the measured and simulated outcomes.Based on the experimental results,the proposed antenna could be helpful for a home breast cancer detection system.

RSS-Based Indoor Localization System with Single Base Station

The paper proposes an Indoor Localization System(ILS)which uses only one fixed Base Station(BS)with simple non-reconfigurable antennas.The proposed algorithm measures Received Signal Strength(RSS)and maps it to the location in the room by estimating signal strength of a direct line of sight(LOS)signal and signal of the first order reflection from the wall.The algorithm is evaluated through both simulations and empirical measurements in a furnished open space office,sampling 21 different locations in the room.It is demonstrated the system can identify user’s real-time location with a maximum estimation error below 0.7 m for 80%confidence Cumulative Distribution Function(CDF)user level,demonstrating the ability to accurately estimate the receiver’s location within the room.The system is intended as a cost-efficient indoor localization technique,offering simplicity and easy integration with existing wireless communication systems.Unlike comparable single base station localization techniques,the proposed system does not require beam scanning,offering stable communication capacity while performing the localization process.

Left-Handed Characteristics Tunable C-Shaped Varactor Loaded Textile Metamaterial for Microwave Applications

This paper presents a textile-based C-shaped split-ring resonators(SRR)metamaterial(MTM)unit cells with an electrical tunability function.The proposed MTM was composed of two symmetrical C-shaped SRR combined with a central diagonal metal bar,whereas the RF varactor diode is placed on the backside of the splitted ground plane.Stopband behavior of single and array MTM unit cells were analyzed while the achieved negative index physical characteristics were widely studies.Though four different MTM arrays(i.e.,1×1,1×2,2×1,and 2×2)were analyzed in simulation,a 2×2-unit cell array was chosen to fabricate,and it was further undergone experimental validation.This proposed tunable MTM exhibits double negative(DNG)/left-handed properties with an average bandwidth of more than 2.8 GHz.Furthermore,attainable negative permittivity and negative permeability are within 2.66 to 9.59 GHz and within 2.77 to 15 GHz,respectively,at the frequency of interest(between 1 and 15 GHz).Moreover,the proposed tunable MTM also showed tunable transmission coefficient characteristics.The proposed electrically tunable textile MTM might function in a dynamic mode,making it suitable for a variety of microwave-wearable applications.A satisfactory agreement between simulations and experiments were achieved,demonstrating that the proposed MTM can operate over a wide bandwidth.

Super Compact UWB Monopole Antenna for Small IoT Devices

This article introduces a novel,ultrawideband(UWB)planar monopole antenna printed on Roger RT/5880 substrate in a compact size for small Internet of Things(IoT)applications.The total electrical dimensions of the proposed compact UWB antenna are 0.19λo×0.215λo×0.0196λo with the overall physical sizes of 15 mm×17 mm×1.548 mm at the lower resonance frequency of 3.8 GHz.The planar monopole antenna is fed through the linearly tapered microstrip line on a partially structured ground plane to achieve optimum impedance matching for UWB operation.The proposed compact UWB antenna has an operation bandwidth of 9.53 GHz from 3.026 GHz up to 12.556 GHz at−10 dB return loss with a fractional bandwidth(FBW)of about 122%.The numerically computed and experimentally measured results agree well in between.A detailed time-domain analysis is additionally accomplished to verify the radiation efficiency of the proposed antenna design for the ultra-wideband signal propagation.The fabricated prototype of a compact UWB antenna exhibits an omnidirectional radiation pattern with the low peak measured gain required of 2.55 dBi at 10 GHz and promising radiation efficiency of 90%.The proposed compact planar antenna has technical potential to be utilized in UWB and IoT applications.