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A traffic sensing and monitoring system based on a magnetometer is proposed to work with Arduino pro-mini and nRF24L01 to mitigate traffic congestion problems. As vehicles pass through the magnetometer buried underground, the microcontroller processes the magnetic field changes and transmits them by the nRF24L01 transceiver for data analysis. A MIFA antenna resonating at 2.4 GHz is incorporated in the transceiver module for transmission purposes. The performance of this antenna is simulated by using COMSOL commercial software. Approximate 7 dB of return loss enhancement is found when taper design is applied to the antenna. Since the antenna is designed to radiate at 2.4 GHz, its antenna gain is the highest (1.22 dBi) in this frequency too. The simulated 3D and 2D gain patterns have shown that this antenna is radiating omnidirectional, suitable for transmitting signals in all directions. This is further validated by the Received Signal Strength Indicator (RSSI) measurement, which indicates a similar trend of signal strength for all locations at a distance below 40 m (-87 dBm). When the distances increase beyond 40 m, the RSSI at the direction closer to the traffic flow drops significantly compared to the other directions where 30 dBm of variation is detected at 100 m.

Background: The correlation of ERBB2 copy number gain (CNG) from tissue or circulating tumor DNA (ctDNA) by next-generation sequencing (NGS) with standard HER2 tissue evaluation is not well understood. Materials and Methods: We retrospectively identified patients with ERBB2 CNG on commercial NGS. We described their clinical-pathologic features and calculated the positive predictive value (PPV) of ERBB2 CNG by NGS for HER2-positivity by IHC and FISH testing. Results: 176 patients had NGS revealing an ERBB2 CNG (112 by tumor tissue and 91 by ctDNA). The cancer subtypes with the most cases with ERBB2 CNG by NGS were breast (n = 67), non-small cell lung (n = 25), colorectal (n = 18), gastroesophageal (n = 17), pancreatic (n = 11), and uterine (n = 11). The PPV of ERBB2 CNG in determining HER2 positivity by standard IHC/FISH definitions was 88% for tissue NGS (n = 57) and 80% for ctDNA (n = 47). The PPV among breast cancer patients for tissue NGS was 97% (n = 35) and ctDNA was 93% (n = 39). However, for non-breast cancer cases, the PPV of ERBB2 amplification by tissue NGS dropped to 76% (n = 22) and by ctDNA to 44% (n = 7). Conclusions: ERBB2 CNG by NGS is detected in numerous malignancies for which HER2 testing is not standard. Detection of ERBB2 CNG by tissue NGS and ctDNA has a high PPV for true HER2-positivity by standard IHC and/or FISH testing in breast cancer.

In this paper, a high-performance antenna-on-chip (AoC) is implemented on gallium arsenide (GaAs) wafer based on the substrate integrated waveguide (SIW) and metasurface (MTS) technologies for terahertz band applications. The proposed antenna is constructed using fve stacked layers comprising metal-GaAs-metal-GaAs-metal. The conductive electromagnetic radiators are implemented on the upper side of the top GaAs layer, which has a metallic ground-plane at its underside. The metallic feedline is implemented at the underside of the bottom GaAs layer. Dual wrench-shaped radiators are framed by metallic vias connected to the ground-plane to create SIW cavity. This technique mitigates the surface waves and the substrate losses, thereby improving the antenna’s radiation characteristics. The antenna is excited by a T-shaped feedline implemented on the underside of the bottom GaAs substrate layer. Electromagnetic (EM) energy from the feedline is coupled to the radiating elements through the circular and linear slots etched in the middle ground-plane layer. To mitigate the surfacewave interactions and the substrate losses in the bottom GaAs layer, the feedline is contained inside a SIW cavity. To enhance the antenna’s performance, the radiators are transformed into a metamaterialinspired surface (i.e., metasurface), by engraving periodic arrangement of circular slots of subwavelength diameter and periodicity. Essentially, the slots act as resonant scatterers, which control the EM response of the surface. The antenna of dimensions of 400× 400 × 8 μm3 is demonstrated to operate over a wide frequency range from 0.445 to 0.470THz having a bandwidth of 25GHz with an average return-loss of− 27 dB. The measured average gain and radiation efciency are 4.6 dBi and 74%, respectively. These results make the proposed antenna suitable for AoC terahertz applications. Dr. Mohammad Alibakhshikenari acknowledges support from the CONEX-Plus programme funded by Universidad Carlos III de Madrid and the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 801538. This work was supported by Ministerio de Ciencia, Innovación y Universidades, Gobierno de España (Agencia Estatal de Investigación, Fondo Europeo de Desarrollo Regional -FEDER-, European Union) under the research grant PID2021-127409OB-C31 CONDOR.

Flexible dielectric materials with environmental-friendly, low-cost and high-energy density characteristics are in increasing demand as the world steps into the new Industrial 4.0 era. In this work, an elastomeric nanocomposite was developed by incorporating two components: cellulose nanofibrils (CNFs) and recycled alum sludge, as the reinforcement phase and to improve the dielectric properties, in a bio-elastomer matrix. CNF and alum sludge were produced by processing waste materials that would otherwise be disposed to landfills. A biodegradable elastomer polydimethylsiloxane was used as the matrix and the nanocomposites were processed by casting the materials in Petri dishes. Nanocellulose extraction and heat treatment of alum sludge were conducted and characterized using various techniques including scanning electron microscopy (SEM), thermogravimetric analysis/derivative thermogravimetric (TGA/DTG) and X-ray diffraction (XRD) analysis. When preparing the nanocomposite samples, various amount of alum sludge was added to examine their impact on the mechanical, thermal and electrical properties. Results have shown that it could be a sustainable practice of reusing such wastes in preparing flexible, lightweight and miniature dielectric materials that can be used for energy storage applications.

In this paper, a high-performance antenna-on-chip (AoC) is implemented on gallium arsenide (GaAs) wafer based on the substrate integrated waveguide (SIW) and metasurface (MTS) technologies for terahertz band applications. The proposed antenna is constructed using five stacked layers comprising metal-GaAs-metal-GaAs-metal. The conductive electromagnetic radiators are implemented on the upper side of the top GaAs layer, which has a metallic ground-plane at its underside. The metallic feedline is implemented at the underside of the bottom GaAs layer. Dual wrench-shaped radiators are framed by metallic vias connected to the ground-plane to create SIW cavity. This technique mitigates the surface waves and the substrate losses, thereby improving the antenna's radiation characteristics. The antenna is excited by a T-shaped feedline implemented on the underside of the bottom GaAs substrate layer. Electromagnetic (EM) energy from the feedline is coupled to the radiating elements through the circular and linear slots etched in the middle ground-plane layer. To mitigate the surface-wave interactions and the substrate losses in the bottom GaAs layer, the feedline is contained inside a SIW cavity. To enhance the antenna's performance, the radiators are transformed into a metamaterial-inspired surface (i.e., metasurface), by engraving periodic arrangement of circular slots of sub-wavelength diameter and periodicity. Essentially, the slots act as resonant scatterers, which control the EM response of the surface. The antenna of dimensions of 400 × 400 × 8 μm

Large impact-melt pockets in shergottites contain both Martian regolith components and sulfide/sulfite bleb clusters that yield high sulfur concentrations locally compared to bulk shergottites. The regolith may be the source of excess sulfur in the shergottite melt pockets. To explore whether shock and release of secondary Fe-sulfates trapped in host rock voids is a plausible mechanism to generate the shergottite sulfur bleb clusters, we carried out shock recovery experiments on an analog mixture of ferric sulfate and Columbia River basalt at peak pressures of 21 and 31 GPa. The recovered products from the 31 GPa experiment show mixtures of Fe-sulfide and Fe-sulfite blebs similar to the sulfur-rich bleb clusters found in shergottite impact melts. The 21 GPa experiment did not yield such blebs. The collapse of porosity and local high-strain shear heating in the 31 GPa experiment presumably created high-temperature hotspots (~2000 °C) sufficient to reduce Fe³⁺ to Fe²⁺ and to decompose sulfate to sulfite, followed by concomitant reduction to sulfide during pressure release. Our results suggest that similar processes might have transpired during shock production of sulfur-rich bleb clusters in shergottite impact melts. It is possible that very small CO presence in our experiments could have catalyzed the reduction process. We plan to repeat the experiments without CO.

This study presents an underground subsurface wireless sensor for drainage infrastructure water level monitoring. It operates from 800 to 2170 MHz to cover the required GSM850/900, GSM1800/1900 and Universal Mobile Telecommunications System (UMTS) bands. The system consists of a wideband antenna, transceiver, data acquisition unit and an ultrasonic sensor. The proposed antenna is a three-dimensional inverted double F antenna and has an envelope size of 90 × 63.5 × 32 mm 3 , which is acceptably small for a cramped subsurface passageway environment. The antenna design was developed using software simulation to optimise its key parameters of return loss and radiation pattern, these were evaluated both in free space and in the partially underground environment. The design developed was then realised in hardware and tested in a representative subsurface location: a utility manhole chamber. It was found that the location of the antenna in the chamber had a significant effect on its performance, but a location that was acceptable for operational purposes was found by experiment. The overall system, including a transceiver, was demonstrated to operate satisfactorily for utility monitoring purposes, including acceptable levels of path loss for communication with mobile communication base stations.

This paper presents a new optimization algorithm based on the behavior of the fungi kingdom expansion (FKE) to optimize the radiation pattern of the array antenna. The immobile mass expansion of the fungi is mimicked in this work as a chaotic behavior with a sinusoidal map function, while the mobile mass expansion is realized by a linear function. In addition, the random germination of the spores is utilized for randomly distributing the variables that are far away from the best solution. The proposed FKE algorithm is applied to optimize the radiation pattern of the antenna array, and then its performance is compared with that of some well-known algorithms. The MATLAB simulation results verify the superiority of the proposed algorithm in solving 20-element antenna array problems such as sidelobe reduction with sidelobe ratio (SLR = 25.6 dB), flat-top pattern with SLR = 23.5 dB, rectangular pattern with SLR = 19 dB, and anti-jamming systems. The algorithm also results in a 100% success rate for all of the mentioned antenna array problems.

The development of concentrating photovoltaic (PV) started in 1960s and over the years, a variety of concentrator designs have been explored. One of its applications is for use in building integrated photovoltaic (BIPV) with the aim of producing a cheaper alternative to a traditional PV panel. This paper presents the experimental characterization of a low concentrating photovoltaic (LCPV) unit that utilizes a reverse truncated pyramid (RTP) concentrator design. The RTP has a geometrical gain of 3.61 and a total height of 40 mm. The result from indoor characterization shows that the RTP-PV device could achieve an opto-electronic gain of 3.0 with a measured half-acceptance angle of ±23.8˚. The RTP-PV can be used as a suitable alternative to traditional solar PV panels.

This paper presents the results of a study on developing an effective technique to increase the performance characteristics of antenna arrays for sub-THz integrated circuit applications. This is essential to compensate the limited power available from sub-THz sources. Although conventional array structures can provide a solution to enhance the radiation-gain performance however in the case of small-sized array structures the radiation properties can be adversely affected by mutual coupling that exists between the radiating elements. It is demonstrated here the effectiveness of using SIW technology to suppress surface wave propagations and near field mutual coupling effects. Prototype of 2 × 3 antenna arrays were designed and constructed on a polyimide dielectric substrate with thickness of 125 mum for operation across 0.19-0.20 THz. The dimensions of the array were 20 × 13.5 × 0.125 mm3. Metallization of the antenna was coated with 500 nm layer of Graphene. With the proposed technique the isolation between the radiating elements was improved on average by 22.5 dB compared to a reference array antenna with no SIW isolation. The performance of the array was enhanced by transforming the patch to exhibit metamaterial characteristics. This was achieved by embedding the patch antennas in the array with sub-wavelength slots. Compared to the reference array the metamaterial inspired structure exhibits improvement in isolation, radiation gain and efficiency on average by 28 dB, 6.3 dBi, and 34%, respectively. These results show the viability of proposed approach in developing antenna arrays for application in sub-THz integrated circuits. This work was supported in part by the Ministerio de Ciencia, Innovación y Universidades, Gobierno de España (MCIU/AEI/FEDER, UE) under Grant RTI2018-095499-B-C31, in part by the Innovation Programme under Grant H2020-MSCA-ITN-2016 SECRET-722424, and in part by the U.K. Engineering and Physical Sciences Research Council (EPSRC) under Grant EP/E022936/1.

The paper demonstrates an effective technique to significantly enhance the bandwidth and radiation gain of an otherwise narrowband composite right/left-handed transmission-line (CRLH-TL) antenna using a non-Foster impedance matching circuit (NF-IMC) without affecting the antenna’s stability. This is achieved by using the negative reactance of the NF-IMC to counteract the input capacitance of the antenna. Series capacitance of the CRLH-TL unit-cell is created by etching a dielectric spiral slot inside a rectangular microstrip patch that is grounded through a spiraled microstrip inductance. The overall size of the antenna, including the NF-IMC at its lowest operating frequency is 0.335λ0 × 0.137λ0 × 0.003λ0, where λ0 is the free-space wavelength at 1.4 GHz. The performance of the antenna was verified through actual measurements. The stable bandwidth of the antenna for |S11|≤ − 18 dB is greater than 1 GHz (1.4–2.45 GHz), which is significantly wider than the CRLH-TL antenna without the proposed impedance matching circuit. In addition, with the proposed technique the measured radiation gain and efficiency of the antenna are increased on average by 3.2 dBi and 31.5% over the operating frequency band. This work is partially supported by RTI2018-095499-B-C31, Funded by Ministerio de Ciencia, Innovación y Universidades, Gobierno de España (MCIU/AEI/FEDER,UE), and innovation programme under grant agreement H2020-MSCA-ITN-2016 SECRET-722424 and the financial support from the UK Engineering and Physical Sciences Research Council (EPSRC) under grant EP/E022936/1.

In this communication, a novel dual-polarized highly folded self-grounded Bowtie antenna that is excited through I-shaped slots is proposed for applications in sub-6 GHz 5G multiple-input-multipleoutput (MIMO) antenna systems. The antenna consists of two pairs of folded radiation petals whose base is embedded in a double layer of FR-4 substrate with a common ground-plane which is sandwiched between the two substrate layers. The ground-plane is defected with two I-shaped slots located under the radiation elements. Each pair of radiation elements are excited through a microstrip line on the top layer with RF signal that is 180º out of phase with respect to each other. The RF signal is coupled to the pair of feedlines on the top layer through the I-shaped slots from the two microstrip feedlines on the underside of the second substrate. The proposed feed mechanism gets rid of the otherwise bulky balun. The Bowtie antenna is a compact solution with dimensions of 32 × 32 × 33.8 mm3.Measured results have verified that the antenna operates over a frequency range of 3.1–5 GHz and exhibits an average gain and antenna efficiency in the vertical and horizontal polarizations of 7.5 dBi and 82.6%, respectively. This project has received funding in part by the Universidad Carlos III de Madrid and the European Union’s Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Grant 801538, in part by the Ministerio de Ciencia, Innovación y Universidades, Gobierno de Spain (MCIU/AEI/FEDER, UE) under Grant RTI2018-095499- B-C31, in part by the Innovation Program under Grant H2020-MSCA-ITN- 2016 SECRET-722424, and in part by the U.K. Engineering and Physical Sciences Research Council (EPSRC) under Grant EP/E022936/1.

In this letter, a set of singular integral formulations are derived to calculate the surface impedance matrix on the antenna array elements. The proposed mathematical model enables electrodynamic analysis of antenna arrays designed using metamaterial-inspired structures. The formulations allow the determination of the array’s impedance, spatial, and polarization\ud characteristics at significantly low computational cost compared to conventional electromagnetic (EM) solvers based on method-of-moments (MoM) numerical technique. The accuracy of the surface impedance results obtained from the theoretical formulations is verified using the full-wave EM software. It is shown that there is excellent agreement between the proposed formulations and EM software. The accuracy of the theoretical model presented is valid for single-layer structures.

This paper presents the results of a study on improving the performance parameters such as the impedance bandwidth, radiation gain and efficiency, as well as suppressing substrate loss of an innovative antenna for on-chip implementation for millimetre-wave and terahertz integrated-circuits. This was achieved by using the metamaterial and the substrate-integrated waveguide (SIW) technologies. The on-chip antenna structure comprises five alternating layers of metallization and silicon. An array of circular radiation patches with metamaterial-inspired crossed-shaped slots are etched on the top metallization layer below which is a silicon layer whose bottom surface is metalized to create a ground plane. Implemented in the silicon layer below is a cavity above which is no ground plane. Underneath this silicon layer is where an open-ended microstrip feedline is located which is used to excite the antenna. The feed mechanism is based on the coupling of the electromagnetic energy from the bottom silicon layer to the top circular patches through the cavity. To suppress surface waves and reduce substrate loss, the SIW concept is applied at the top silicon layer by implementing the metallic via holes at the periphery of the structure that connect the top layer to the ground plane. The proposed on-chip antenna has an average measured radiation gain and efficiency of 6.9 dBi and 53%, respectively, over its operational frequency range from 0.285–0.325 THz. The proposed on-chip antenna has dimensions of 1.35 × 1 × 0.06 mm3. The antenna is shown to be viable for applications in millimetre-waves and terahertz integrated-circuits. © 2020, The Author(s). Open access funding provided by Università degli Studi di Roma Tor Vergata within the CRUI-CARE Agreement. This work is partially supported by RTI2018-095499-B-C31, Funded by Ministerio de Ciencia, Innovación y Universidades, Gobierno de España (MCIU/AEI/FEDER, UE), innovation programme under grant agreement H2020-MSCA-ITN-2016 SECRET-722424 and the financial support from the UK Engineering and Physical Sciences Research Council (EPSRC) under grant EP/E022936/1.

A compact fabric antenna structure integrated with electromagnetic bandgap structures (EBGs) covering the desired frequency spectrum between 2.36 GHz and 2.40 GHz for Medical Body-Area Networks (MBANs), is introduced. The needs of flexible system applications, the antenna is preferably low-profile, compact, directive, and robust to the human body's loading effect have to be satisfied. The EBGs are attractive solutions for such requirements and provide efficient performance. In contrast to earlier documented EBG backed antenna designs, the proposed EBG behaved as shielding from the antenna to the human body, reduced the size, and acted as a radiator. The EBGs reduce the frequency detuning due to the human body and decrease the back radiation, improving the antenna efficiency. The proposed antenna system has an overall dimension of 46×46×2.4 mm3. The computed and experimental results achieved a gain of 7.2 dBi, a Front to Back Ratio (FBR) of 12.2 dB, and an efficiency of 74.8%, respectively. The Specific Absorption Rate (SAR) demonstrates a reduction of more than 95% compared to the antenna without EBGs. Moreover, the antenna performance robustness to human body loading and bending is also studied experimentally. Hence, the integrated antenna-EBG is a suitable candidate for many wearable applications, including healthcare devices and related applications.

Combined sewer overflow structures (CSO) play an important role in sewer networks. When the local capacity of a sewer system is exceeded during intense rainfall events, they act as a &ldquo, safety valve&rdquo, and discharge excess rainfall run-off and wastewater directly to a natural receiving water body, thus preventing widespread urban flooding. There is a regulatory requirement that solids in CSO spills must be small and their amount strictly controlled. Therefore, a vast majority of CSOs in the UK contain screens. This paper presents the results of a feasibility study of using low-cost, low-energy acoustic sensors to remotely assess the condition of CSO screens to move to cost-effective reactive maintenance visits. In situ trials were carried out in several CSOs to evaluate the performance of the acoustic sensor under realistic screen and flow conditions. The results demonstrate that the system is robust within &plusmn, 2.5% to work successfully in a live CSO environment. The observed changes in the screen condition resulted in 8&ndash, 39% changes in the values of the coefficient in the proposed acoustic model. These changes are detectable and consistent with observed screen and hydraulic data. This study suggested that acoustic-based sensing can effectively monitor the CSO screen blockage conditions and hence reduce the risk of non-compliant CSO spills.

A novel microwave technology-based biosensor operating at 36 GHz is developed for liquid-sensing properties for 5G applications. The metamaterial resonator in the designed biosensor consists of a single ring connected by two microstrip lines. The overall dimensions of the biosensor are $5 \times 8$ mm2. The simulated results demonstrate the resonant frequency drops as the MUT of higher permittivity value is introduced in place of the gap of the ring resonator. Therefore, the proposed metamaterial ring resonator can provide good sensitivity when sensing the MUT that are resonant in mm-W for 5G applications.

A compact and robust inversely E-shaped antenna (IESA) integrated with electromagnetic band-gap (EBG) is presented for wearable applications at 2.4 GHz. The EBG introduced in this paper to shield the antenna from body effects, due to its high natural dielectric. With EBG, the antenna shows good performance under bending and loading human body. The design has overall dimension of $46 \times 46 \times 2.4$ mm3. The integration of antenna with EBG shows an improvement of a gain of 7.8 dBi and bandwidth of 27%. It also reduces the specific absorption rate (SAR) by more than 95.

Analogue-to-digital converters (ADC) using oversampling technology and the &Sigma, ∆ modulation mechanism are widely applied in digital audio systems. This paper presents an audio modulator with high accuracy and low power consumption by using a discrete second-order feedforward structure. A 5-bit successive approximation register (SAR) quantizer is integrated into the chip, which reduces the number of comparators and the power consumption of the quantizer compared with flash ADC-type quantizers. An analogue passive adder is used to sum the input signals and it is embedded in a SAR ADC composed of a capacitor array and a dynamic comparator which has no static power consumption. To validate the design concept, the designed modulator is developed in a 180 nm CMOS process. The peak signal to noise distortion ratio (SNDR) is calculated as 106 dB and the total power consumption of the chip is recorded as 3.654 mW at the chip supply voltage of 1.8 V. The input sine wave of 0 to 25 kHz is sampled at a sampling frequency of 3.2 Ms/s. Moreover, the results achieve a 16-bit effective number of bits (ENOB) when the amplitude of the input signal is varied between 0.15 and 1.65 V. By comparing with other modulators which were realized by a 180 nm CMOS process, the proposed architecture outperforms with lower power consumption.

A closely packed wideband multiple-input multiple-output (MIMO)/diversity antenna (of two ports) with a small size of less than 18.5 mm by 18.5 mm is proposed for mobile communication applications. The antenna can be orthogonally configured for corner installation or by placing it on a back-to-back structure for compact modules. To enhance the isolation and widen the bandwidth, the antenna is structured with multiple layers having differing dielectric constants. The feeding through a via significantly reduces the ground waves. A multi-fidelity surrogate model-assisted design exploration method is employed to obtain the optimized antenna geometric parameters efficiently. The antenna design was investigated using electromagnetic simulation and a physical realization of the optimal design was then created and subjected to a range of tests. The specific parameters investigated included reflection coefficients, mutual coupling between the input ports, radiation patterns, efficiency and parameters specific to MIMO behavior: envelope correlation coefficient and pattern diversity multiplexing coefficient. It was found that the antenna has an impedance bandwidth of approximately 4 GHz, mutual coupling between input ports of better than &minus, 18 dB and an envelope correlation coefficient of less than 0.002 across the operating band. This makes it a good candidate design for many mobile MIMO applications.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

A feasibility study is presented on the performance parameters of a novel on-chip antenna based on metasurface technology at terahertz band. The proposed metasurface on-chip antenna is constructed on an electrically thin high-permittivity gallium arsenide (GaAs) substrate layer. Metasurface is implemented by engraving slot-lines on an array of 11 × 11 circular patches fabricated on the top layer of the GaAs substrate and metallic via-holes implemented in the central patch of each row constituting the array, which connects the patch to the leaky-wave open-ended feeding slot-lines running underneath the patches. The slot-lines are connected to each other with a slit. A waveguide port is used to excite the array via slot-lines that couple the electromagnetic energy to the patches. The metasurface on-chip antenna is shown to exhibit an average measured gain in excess of 10 dBi and radiation efficiency above 60% over a wide frequency range from 0.41 to 0.47 THz, which is significant development over other on-chip antenna techniques reported to date. Dimensions of the antenna are 8.6 × 8.6 × 0.0503mm3. The results show that the proposed GaAs-based metasurface on-chip antenna is viable for applications in terahertz integrated circuits.

The paper shows the gain-bandwidth limitations of traditional discrete component matching used in electrically small antennas can be overcome by implementing the impedance matching network with metasurface. The proposed metasurface can optimize maximum power transfer to electrically small antennas and achieve superior broadband performance.

This paper presents an energy harvesting circuit for high efficiency performance. The proposed circuit consists of an RLC shunt resonance circuit integrated to a RF antenna. The resonance circuit is used to (i) selectively pick the desired signal whose output is fed to a Cockcroft-Walton voltage multiplier circuit; and (ii) match the impedance of the antenna with the Cockcroft-Walton voltage multiplier circuit for optimum power (DC) transfer. The proposed circuit exhibits an efficiency of 68% for an input power of $200\ \mu\mathrm{W}$ .

This paper presents a simple prototype of a metasurface-based on-chip antenna operating in 0.3-0.32 THz. The proposed structure is constructed from two layers of polyimide-substrates with thickness of 0.1mm that sandwich a middle metallic ground-plane layer of 50-micron thickness. A series of linear slots of varying lengths are etched on the radiation patches of the top-layer to create a metasurface. This is shown to enhance the antenna's effective aperture area that improves its radiation performance without affecting the overall antenna's footprint. To reduce the surface-waves and substrate-losses a meander-line slits has realized inside the ground-plane. The antenna is fed by an open-ended microstrip feedline located on the bottom-layer. The feedline consists of three-branches that are aligned under each radiation patch to achieve the maximum electromagnetic (EM) transfer from bottom-side of the bottom layer to the topside of the top-layer. Coupling of the EM energy from the bottom-layer to the top-layer is via meander-line slits introduced between the two layers. Simulation results show improvement in the on-chip antenna's impedance bandwidth, gain and efficiency.

A new design of band-pass filter (BPF) with variable dual notched bands characteristic is introduced for ultra-wideband (UWB) applications. The configuration of the proposed BPF contains a rectangular-ring stub loaded with parallel-coupled lines and an inverted T-shaped electromagnetic band-gap (EBG) resonator is proposed in this letter. It is designed on a Rogers 5880 substrate with properties of ε= 2.2, δ= 0.0009, and h=1 mm. The proposed BPF exhibits a wide usable fractional bandwidth from 3.1 to 10.6 GHz and two-frequency notch-bands at 5 and 8 GHz. Due to the simple configuration and excellent characteristics of the presented design with tubule dual notch function, the proposed BPF is useful to be used in UWB communication networks.