Showing 10 results for Wideband
R. Mirzalou, A. Nabavi, Gh. Darvish,
Volume 8, Issue 3 (9-2012)
Abstract
This paper presents a new ultra-wideband LNA which employs the complementary derivative superposition method in noise cancellation structure. A pMOS transistor in weak inversion region is employed for simultaneous second- and third-order distortion cancellation. Source-degeneration technique and two shunt inductors are added to improve the performance at high frequencies. The degeneration inductor resonates at fT/2 and realizes a new input matching technique that widens the bandwidth with decreasing its quality factor and input capacitance, while flattens the input resistance and also improves the 1dB Compression Point. The shunt inductors resonate at the center frequency of the band and improve the effective bandwidth of noise/distortion cancellation technique. This LNA has been designed in a 0.18-μm CMOS process and consumes 8.3 mA from 1.8 V power supply. The chip area is 0.55mm2. The noise figure and voltage gain are 4.48-5.18 dB and 13 dB, respectively. S11 is lower than -13.5 dB over 5.8–10.6 GHz and IIP3 is 14.5–17.5 dBm, IIP2 is 14–15.5 dBm. This technique improves IIP3 more than 9dB.
N. Noori,
Volume 10, Issue 2 (6-2014)
Abstract
In this paper, an optimal approach to design wideband tapped-delay line (TDL) array antenna is proposed. This approach lets us control the array angular and frequency response over a wide frequency band. To this end, some design restrictions are defined and a multi-objective optimization problem is constructed by putting the individual restrictions together. The optimal weights of the TDL processor are determined through solving this multi-objective problem. A design example is presented to show performance of the proposed method and compare the array response with those previously published in the literature.
B. Zakeri, H. Bernety,
Volume 10, Issue 4 (12-2014)
Abstract
Band-notch characteristic has been of great interest recently to overcome the electromagnetic interference of Ultra-wideband systems (UWB) with other existing ones. In this paper, we present a novel microstrip-fed antenna with band rejection property appropriate for UWB applications. Band-notch characteristic has been achieved by adding a rectangular resonant element to the ground section. A prototype was fabricated and measured based upon optimal parameters. Experimental results show consistency with simulation results. Measurement results confirm that the antenna covers the UWB band and satisfies a band rejection in the frequency span of 5 GHz to 5.7 GHz to restrain it from interference with Wireless Local Area Network (WLAN). Then, to achieve better isolation, a rectangular strip is appended to the band-notch creating part of the ground section to enhance obtained VSWR up to 30 through simulation. In addition, by applying a similar technique, a dual band-notched characteristic with an average simulated VSWR of around 13.75 has been achieved for WLAN and the downlink of X band satellite communication systems with each more than 10. Features such as small size, omnidirectional pattern and perfect isolation make the antenna suitable for any UWB applications.
Y. Zehforoosh, M. Sefidi,
Volume 13, Issue 2 (6-2017)
Abstract
In this article, we present a new design of a coplanar waveguide fed (CPW-fed) ultra-wideband (UWB) antenna with dual band-notched characteristics. Two notched frequency bands are achieved by using two inverted U-shaped stepped impedance resonators. The proposed antenna can operate from 2.82 to 11 GHz (118%), defined by VSWR< 2, except two notched bands around 3.5 GHz (WiMAX) and 5.5 GHz (WLAN). The size of the antenna is 20×20×1.6 mm3. The experimental and simulated results of the prototyped antenna, including voltage standing wave ratio (VSWR), radiation pattern, and gain characteristics are presented and discussed. In addition, Analytical Hierarchy Process (AHP) method used for comparison the proposed antenna with previous designed structures.
M. A. Trimukhe, B. G. Hogade,
Volume 15, Issue 2 (6-2019)
Abstract
In this paper a particle swarm optimization (PSO) algorithm is presented to design a compact stepped triangle shape antenna in order to obtain the proper UWB bandwidth as defined by FCC. By changing the various cavity dimensions of the antenna, data to develop PSO program in MATLAB is achieved. The results obtained from the PSO algorithm are applied to the antenna design to fine-tune the bandwidth. Bandwidth optimization for ultra-wideband frequency of 3.1 GHz to 10.6 GHz is achieved by applying PSO algorithm. High-Frequency Structure Simulator (HFSS) software tool is used for the simulation. An optimized antenna is fabricated, tested and test results are found in accordance with simulation results.
A. Chaabane, M. Guerroui,
Volume 17, Issue 4 (12-2021)
Abstract
A new design of a Coplanar Waveguide-Fed (CPW) Ultra Wideband (UWB) Rhombus-shaped antenna for Ground Penetrating Radar (GPR) applications is designed and discussed in this work. The antenna has a simple design which is composed by a rhombus-shaped patch and a modified ground plane. The working bandwidth is improved by removing the metal from the upper part of the ground plane surrounding the patch and by introducing a corrugation geometry in the ground plane. The proposed antenna was designed on a low-cost FR4-substrate having a compact size of 0.2721λ0×0.2093λ0×0.0157λ0 at 3.14 GHz. All the simulations were carried out by using the commercially software CST Microwave StudioTM. The simulated results show that the designed antenna covers an UWB extending from 3.14 GHz to 13.82 GHz (125.94%) and indicate excellent radiation performances throughout the operating bandwidth. The measured bandwidth is nearly extending between 3.95 GHz and 13.92 GHz (111.58%). Besides, the antenna bandwidth response was checked in close proximity to a mass of Concrete. The obtained results are satisfactory and assure the efficiency of the designed antenna to work as a GPR antenna.
B. Dorostkar Yaghouti,
Volume 19, Issue 2 (6-2023)
Abstract
By increasing the transceiver devices within the 3.1 to 10.6 GHz frequency band, the interferers and strong blockers from different equipment degraded the main received signals, so linearity performance becomes more notable. In this paper, a two-path low noise amplifier (LNA) is proposed for satisfying the overall efficiency of the Ultra-wideband (UWB) radar used in vital sign detection, precise indoor localization, and high data rate wireless communications. A novel high linear circuit is recommended based on Complementary Derivative Superposition (CDS) and Post Distortion (PD) techniques. High pass filter and inductive source degeneration structured input impedance matching. Post layout results of the designed UWB-LNA in 180-nm CMOS represented the average of third-order Intercept Point (IIP3) is 8.1 dBm, S21 is 11 dB and, S11 is below -10 dB. The minimum noise figure (NF) is 3.11 dB. The circuit draws 12.7 mA at 1.4-V. The chip area is 930 µm × 1090 µm. The proposed design in this work exhibits higher FOM compared to similar LNAs, It is clear, high-linearity performance in total bandwidth is an advantage compared to recent articles.
Ayoub Hamidi, Ahmad Cheldavi, Asghar Habibnejad Korayem,
Volume 20, Issue 3 (9-2024)
Abstract
This paper proposes a structure for concrete composite materials that effectively attenuates transmitted power through the composite slab across a wide frequency range. The proposed structure is practical for electromagnetic interference shielding applications. To assess its effectiveness, the proposed structure has been compared with two other structures: a traditional wire mesh used in reinforced composites and an array of helices, a cutting-edge technique for manufacturing lightweight concretes with significant improvements in shielding properties. The comparison among full-wave simulation results indicates that the proposed method leverages the benefits of both techniques. It achieves a shielding effectiveness exceeding 30 dB from low frequencies up to 8.5 GHz and beyond 55 dB from low frequencies up to 4 GHz. Furthermore, an experimental measurement was conducted to validate the full-wave simulation results. An experimental sample was fabricated according to the simulated proposed structure, and the measured shielding effectiveness confirmed the composite's capability in wideband electromagnetic shielding. Theoretically, the proposed structure can enhance the concrete's mechanical characteristics while improving its shielding effectiveness, making it suitable for designing ultra-high-performance concretes.
Muhammad Naqib Mohd Shukri, Syed Muhammad Mamduh Syed Zakaria, Ahmad Shakaff Ali Yeon, Ammar Zakaria, Latifah Munirah Kamarudin,
Volume 21, Issue 2 (6-2025)
Abstract
Accurate 3D Localization is very important for a wide range of applications, such as indoor navigation, industrial robotics, and motion tracking. This research focuses on indoor 3D positioning systems using ultra-wideband (UWB) devices. Two localization experiments were conducted using the Least Squares Trilateration method. In the first experiment, anchors were at the same height, while in the second, they were at varying heights. The lowest percentage errors in the first experiment were 0% at the x-axis, 0.21% at the y-axis, and 19.75% at the z-axis. In the second experiment, the lowest percentage errors in the experiment were 1.98% at the x-axis, 0.68% at the y-axis, and 17.86% at the z-axis, demonstrating improved accuracy with varied anchor heights at the axis. This work shows the z-axis measurements are unreliable and noisy due to the limited intersection of signal waves of each anchor in a same height anchors setup.
Zahra Memarian, Mahdi Majidi,
Volume 21, Issue 3 (8-2025)
Abstract
This paper presents a two-dimensional (2D) direction of arrival (DOA) estimation method based on the popular correlative interferometer (CI) approach, incorporating practical considerations. Leveraging the flexibility of software-defined radio (SDR) platforms, the proposed array antenna model is designed according to the specifications of a dual-channel synchronous USRP B210 receiver and an appropriate RF switch. To enhance the speed and accuracy of 2D DOA estimation for narrowband, wideband (WB), and frequency hopping (FH) signals, this study introduces a method that integrates power spectrum density (PSD) and spectrogram analysis of the receiver’s instantaneous bandwidth with an optimized filter bank, to precisely detect active frequencies and their intervals. Additionally, a fast, modified K-means clustering algorithm is developed to refine DOA estimation for FH and WB signals across multiple active subchannels. Simulation results demonstrate improved DOA estimation accuracy in multipath conditions, particularly at longer distances, with further enhancements achieved through the proposed clustering method.
