scholarly journals A six-channel microstrip diplexer for multi-service wireless communication systems

2020 ◽  
Vol 41 (3) ◽  
Author(s):  
Farhad Fouladi ◽  
Abbas Rezaei

In this paper, a six-channel microstrip diplexer is designed and fabricated. It operates at 0.75/0.85/1/1.25/1.6/1.8 GHz for multi-service wireless communication systems. It consists of two stub-loaded resonators, which are integrated by coupled lines. The channels are close together, which makes the proposed diplexer suitable for frequency division duplex (FDD) schemes. The proposed structure has a compact size of 0.025 λg2 where λg is the guided wavelength calculated at 0.75 GHz. The other advantages of the introduced multi-channel diplexer are the low insertion losses of 1.62/1.27/0.43/0.53/1.26 and 1 dB, as well as good return losses of 26/26/25/25/21.7 and 22 dB at 0.75/0.85/1/1.25/1.6/1.8 GHz respectively. A good isolation of less than 22 dB is obtained between the channels. In order to design the presented diplexer a designing technique is used which is based on the proposing of an equivalent approximated LC model and calculating the inductors and capacitors. To confirm the simulation results, the introduced diplexer is fabricated and measured.

Author(s):  
Sunil Raosaheb Gagare . ◽  
Dolly Reney .

The new design methods of microwave filter has proved its significance for use in wireless communication systems. Modern wireless communication systems require microwave filters to have stringent specifications such as compact size, robust, conformal, light weight and more importantly cost effective while maintaining its electrical characteristics. Micro-strip filter design and reconfigurable filters present a better prospectus in this regards as it meets the specifications of modern wireless communication applications. Reconfigurable filters can provide control over parameters such as frequency, bandwidth and selectivity while reducing the need of number of switches sandwiched between electrical components. Different methods have provided a new dimension for designing microwave filters .In this article, we present a review on design methods for reconfigurable band-pass filters for next generation wireless technologies such as 4G, 5G and IOT.


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Hongyuan Gao ◽  
Yangyang Hou ◽  
Shibo Zhang ◽  
Ming Diao

With the further research in communication systems, especially in wireless communication systems, a statistical model called Nakagami-mdistribution appears to have better performance than other distributions, including Rice and Rayleigh, in explaining received faded envelopes. Therefore, the Nakagami-mquantile function plays an important role in numerical calculations and theoretical analyses for wireless communication systems. However, it is quite difficult to operate numerical calculations and theoretical analyses because Nakagami-mquantile function has no exact closed-form expression. In order to obtain the closed-form expression that is able to fit the curve of Nakagami-mquantile function as well as possible, we adopt the method of curve fitting in this paper. An efficient expression for approximating the Nakagami-mquantile function is proposed first and then a novel heuristic optimization algorithm—generalized opposition-based quantum salp swarm algorithm (GO-QSSA)—which contains quantum computation, intelligence inspired by salp swarm and generalized opposition-based learning strategy in quantum space, to compute the coefficients of the proposed expression. Meanwhile, we compare GO-QSSA with three swarm intelligence algorithms: artificial bee colony algorithm (ABC), particle swarm optimization algorithm (PSO), and salp swarm algorithm (SSA). The comparing simulation results reveal that GO-QSSA owns faster convergence speed than PSO, ABC, and SSA. Moreover, GO-QSSA is capable of computing more accurately than traditional algorithms. In addition, the simulation results show that compared with existing curve-fitting-based methods, the proposed expression decreases the fitting error by roughly one order of magnitude in most cases and even higher in some cases. Our approximation is proved to be simple and efficient.


2020 ◽  
Vol 3 (1) ◽  
pp. 6
Author(s):  
Mohammad Monirujjaman Khan

Development and investigation of a miniaturized ultra-wideband band notch antenna is demonstrated in this paper. The antenna was modeled and simulated using Computer Simulation Technology (CST)TM Microwave Studio software. The simulated results of this antenna are presented and analyzed. The performance parameters such as return loss, gain, radiation efficiency, radiation patterns are simulation-based results provided here. The main objective of this paper was to obtain band notch characteristics at the Wireless Local Area Network (5.15–5.8 GHz) and WiMax (5.25–5.85 GHz) in the UWB frequency ranges of 3.1–10.6 GHz in order to avoid interference. Results and analysis show that the antenna meets the objective and shows very good results. It has very compact size as well which is attractive feature of this antenna that will make it suitable for ultra-wideband wireless communication systems.


2019 ◽  
Vol 8 (2S8) ◽  
pp. 1776-1778

In this paper, pilot-assisted techniques for channel estimation (CE) are simulated for Universal Filtered Multi-Carrier (UFMC) modulation scheme. UFMC aims at replacing orthogonal frequency division multiplexing (OFDM) and improves performance and robustness in the case of timefrequency misalignment. These techniques efficiently support Internet of Things (IoT) and massive machine type communications (mMTC), which are identified as challenges for 5G wireless communication systems (WCS). Pilot-aided techniques are adopted and applied to OFDM and UFMC. Simulation results are supplemented to compare the performance of UFMC systems with conventional CP-OFDM systems.


Sign in / Sign up

Export Citation Format

Share Document