This paper presents a compact Multiple Input Multiple Output antenna with high isolation and low envelope correlation (ECC) for fifth-generation applications using spatial diversity technique. The ...proposed MIMO antenna consists of two single antennas, each having size of 13 × 12.8 mm2, symmetrically arranged next to each other. The single and MIMO antennas are simulated and analyzed. To verify the simulated results, the prototype antennas were fabricated and measured. A good agreement between measurements and simulations is obtained. The proposed antenna covers the 28 GHz band (27.5–28.35 GHz) allocated by the FCC for 5G applications. Moreover, the isolation is more than 35 dB and the ECC is less than 0.0004 at the operating band, which means that the mutual coupling between the two elements is negligible. The MIMO parameters, such as diversity gain (DG), total active reflection coefficient (TARC), realized gain, and efficiency, are also studied. Thus, the results demonstrate that our antenna is suitable for 5G MIMO applications.
In this paper, a wideband antenna is proposed for ultra-wideband microwave imaging applications. The antenna is comprised of a tapered slot ground, a rectangular slotted patch and four star-shaped ...parasitic components. The added slotted patch is shown to be effective in improving the bandwidth and gain. The proposed antenna system provides a realized gain of 6 dBi, an efficiency of around 80% on the radiation bandwidth, and a wide impedance bandwidth (S11 < -10 dB) of 6.3 GHz (from 3.8 to 10.1 GHz). This supports a true wideband operation. Furthermore, the fidelity factor for face-to-face (FtF) direction is 91.6%, and for side by side (SbS) is 91.2%. This proves the excellent directionality and less signal distortion of the designed antenna. These high figures establish the potential use of the proposed antenna for imaging. A heterogeneous breast phantom with dielectric characteristics identical to actual breast tissue with the presence of tumors was constructed for experimental validation. An antenna array of the proposed antenna element was situated over an artificial breast to collect reflected and transmitted waves for tumor characterization. Finally, an imaging algorithm was used to process the retrieved data to recreate the image in order to detect the undesirable tumor object inside the breast phantom.
This research article presents the design and realization of a flexible semi-circular shaped ultra-wideband (UWB) printed antenna based on metamaterial superstrate for medical applications. In this ...article, at first, the design of a semi-circle structured UWB patch antenna is performed which provides an ultra-wide impedance bandwidth 2.83–13.57 GHz and a peak gain of 5.17 dBi. In order to ameliorate the radiation performance, an array pattern of 5 × 5 metamaterial (MTM) unit cells are generated and placed over the proposed antenna. Also, both the antenna and the superstrate layer are printed on a flexible teflon material. The proposed design has an overall compact size of 32.1 × 34 × 0.6 mm
3
. Using the superstrate MTM unit cell, the measured operating bandwidth ranges from 4.03 GHz to 14 GHz and the experimental peak gain and radiation efficiency are 6.7 dBi and 97.26%, respectively. Moreover, the conformal analysis is investigated to verify the robustness and the applicability of the prescribed antenna over the curved surfaces. The suggested antenna presents magnificent performance by maintaining ultra-wide bandwidth and offering required radiation characteristics during various bending analysis. Furthermore, the reflection coefficient and specific absorption rate (SAR) of the proposed antenna have been analyzed by placing it on different human body parts such as the hand, arm and chest. The suggested antenna maintains UWB characteristics along with acceptable SAR values for 1 g and 10 g tissues for various on body analysis cases. Hence, this UWB antenna structure can be a convenient choice for implementing on curved surfaces in flexible/bending conditions and also for wearable applications. The prescribed antenna could be useful for portable medical devices within the UWB spectrum.
This paper presents the design strategy of a microwave low noise amplifier (LNA) in microstrip technology for sub-6 GHz 5G communication systems. A microstrip coupler is exploited to design a DC ...block in order to avoid unwanted parasitic effects generated by lumped elements and to facilitate fabrication. Bias and matching networks are implemented using microstrip transmission lines. Based on the designed circuit, a prototype is fabricated and measured using an Agilent Technologies (hp)® ATF13786 field effect transistor. The proposed LNA is simulated and measured at 3.5 GHz. The results demonstrate that the proposed LNA achieves high gain of 12.7 dB, noise figure less than 2 dB, input and output reflection coefficients less than –10 dB, and unconditional stability over the desired bandwidth. Regarding the large signal results, the proposed LNA yields excellent performance with an output power of 16.4 dBm, and a power added efficiency (PAE) of 18%. Furthermore, the proposed LNA exhibits good linearity with an output compression point at 1 dB (OP1dB) of 0 dBm, and a third-order intercept point (OIP3) greater than +37.7 dBm.
•Suggested antenna has a wider BW of 7 GHz (4.1–9.7 GHz).•Good radiation efficiency of more than 85% and realized gain of 5.1 dBi are obtained.•Small size, high gain and UWB capability, the antenna ...is a strong candidate for MWI applications.•The antenna performs admirably in both frequency and time domains with a good fidelity factors of 73% in FtF and acceptable value of 56.7% in SbS.
In this work, a small multilayer ultra-wideband (UWB) patch antenna for microwave breast imaging (MWI) applications was developed both theoretically and experimentally. However, to improve the antenna performance relating to the bandwidth (BW), the radiating element of the suggested initial antenna is modified by adding a modified split ring resonator (SRR) and slits in the patch as well as the ground plane. Then, to achieve the requisite antenna properties for MWI applications such as the gain and directivity, the antenna is equipped with a uniplanar artificial magnetic conductor (AMC) structure made up of a 3 × 3 array of square modified SRR unit cells. The final proposed prototype has a relatively small size of 20 × 19 × 1.6 mm3 and it accomplishes a return loss below -10 dB (S11< -10 dB) at overall BW of 7 GHz (4.1 – 9.7 GHz) with more than 5 dBi realized gain. In this way, the characteristics of the fabricated antenna are measured to examine the antenna performance. Indeed, the fidelity factor of face-to-face (FtF) and side-by-side (SbS) scenarios are also noticed for the same frequency range. In the final analysis, a simulation model of the antennas, which operate as a transceiver, and a breast phantom model with tumor sample are proposed for detecting cancerous tumor cells within the breast.
Hence, the proposed design is suitable in the biomedical applications such as tumor cell detection.
A compact wideband band‐pass microstrip filter based on triangular split ring resonators is presented. The center frequency of the proposed structure is 3.1 GHz and the 3 dB bandwidth results 1.05 ...GHz. Good agreements between the simulated and measured results demonstrates the effectiveness of the proposed design. The size of the filter is 14 × 50 mm2 only.
Radio communications using ultra wideband (UWB) frequency have rapidly developed since the beginning of the year 2000. This technique offers advantages that made it attractive to a large number of ...civilian and military applications. The aim of this work is the study of the geometry features of a UWB antenna and the improvement of the bandwidth by inserting slots. To obtain a very large bandwidth operating from 2 GHZ to 11 GHZ we have inserted slots both on ground plane and antenna.
This paper proposes a microwave-based brain stroke imaging system. A monopole patch antenna is loaded with metamaterials (MTM) surfaces to improve the gain required for stroke detection. A simulated ...configuration is described and analyzed in this work. The proposed system's performance is demonstrated upon placing an array of four element near human head tissue for hemorrhage detection and analysis. The proposed antenna's practicality is established via simulations using a realistic head model by examining the scattering characteristics as well as the Electric (E) and magnetic (H) field distributions inside the head. The reconstructed images show the potential of the conceptual model as a portable platform for efficiently detecting and locating hemorrhages inside the brain using the extracted field distributions.
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