Journal of Innovative Information and Communication Technology

Design of Holographic Beamforming Antenna with Slot-Shaped

2021-11-10T08:09:17+00:00

The future sixth generation (6G) wireless communications expected to construct intelligent network with low-power and high-throughput transmissions. To fulfill such challenging visions in this paper we design Holographic beamforming (HBF) antenna which is developing into a promising solution due to its flexible beamforming capability with lower energy and hardware costs. The HPF consists of an aperture-shaped microwave length array on the metasurfaces (meta-elements) that is different from the conventional phase-controlled antennas. The HPF can control the radiation amplitude and phase of reference wave propagation on the metasurface by leveraging the holographic technique. The PIN diode used in each slot to dynamically tuned between the "on" and "off" states to control the radiation direction. The proposed antenna dimensions are 50mm x 50mm. The substrate used (Rogers 4003, p = 3.38 and tan = 0.0027) and 0.578 mm thick. The feed line coaxial cable in corner to antenna is used to control the air conditioning. The HPF antenna operates at 25.5GHz with a maximum gain of 13dBi and directivity of 15 dBi with antenna efficiency up to 80.8% and achievable bandwidth of 1.4GHz at resonant frequency

Cloud Database Security Issues and Challenges: A Review

2021-11-21T07:44:18+00:00

Recently, cloud computing has been a heavily adopted technology by most businesses, simultaneously, the database has also shifted to the cloud computing environment. This paradigm called cloud database, and it can reduce data management costs and allow new business to focus on the delivered product. Moreover, cloud computing can be mean to solve scalability, flexibility, performance, availability and cost problems. However, security has been identified as a major threat to the cloud database, and it has played a critical role in cloud computing acceptance. Different aspects of security should be considered during the deployment of any cloud database management system. These aspects include abut are not limited to data confidentiality, data integrity, data availability, data privacy, data isolation, and the protection from insider attacks. In this paper, we address the state-of-the-art studies that considered such security challenges and issues facing the adoption of a cloud database. We also propose a conceptual model to summarize and provide a better understanding of these issues and their effect on cloud database. Furthermore, we investigate such issues according their relevant level and show two examples of vendors and the security feature that were practiced for the database on the cloud. Finally, we summarize the open cloud databases security issues and recommend some future directions.

Design Reflective Metasurface elements for wireless network at MMW applications

2021-11-10T08:11:47+00:00

Reconfigurable intelligent surfaces (RISs) are considered a promising technology for the sixth-generation (6G) for wireless applications. RIS has received significant attention for its potential to enhance the coverage and capacity of wireless networks. This paper presents design RIS, a reconfigurable element working at 70 GHz with two PIN diodes are implemented on each unit. By switch the PIN diodes of the element between "ON" and "OFF" states, which result a change in amplitude and the reflected phase of the incident wave, the phase difference is within 180° is accepted by changing the state of diodes from "OFF " to "ON" and 145° phase shift when the states of diodes are "OFF" and "ON" and amplitude of the reflective wave is 0.4. such metasurface achieves dynamical beam deflection and polarization transformation through the reconfigurable design of the phase distribution. Simulation results show good agreement and verify the beam switching functionality of the proposed RIS

Analysis of Out-of-band Emission Reduction for 5G Wireless Communication Transmitter

2021-11-24T08:24:00+00:00

The cellular systems of the Fourth Generation (4G) have been optimized to provide high data rates and reliable coverage to mobile users. Cellular systems of the next generation will face more diverse application requirements: the demand for higher data rates exceeds 4G capabilities; battery-driven communication sensors need ultra-low power consumption; and control applications require very short response times. A unified physical layer waveform, referred to as generalized frequency division multiplexing (GFDM), to address these requirements. This paper conserns several prototype filters(shaping filter) in term of reducing Out Of Band( OOB) emission, then analyze the reducing OOB emission of Fifth Generation( 5G) waveform with comparing between several techniques. Choosing the pulse shaping filters affects the properties of the GFDM signal so we can use for different usages. The GS insertion technique is useful in reducing the OOB radiation but it is not good for application that requires low latency. Pinching technique is most effective in combination with a higher number of guard carriers.In summary, the flexible nature of GFDM makes this waveform a suitable candidate for future 5G systems.

High bandwidth triple-band Microstrip Patch Antenna for THz Application

2021-11-16T08:28:24+00:00

To meet demands of the future realization, new progresses in communication systems require a low-cost, lightweight, low-profile, and high-performance antenna. In this paper triple-band microstrip patch antennas (MPAs) is proposed and designed for THz applications. The proposed antenna has the dimensions of 56.8x 66.8x 5pm3, uses Quartz-glass as a substrate material with a loss tangent =0 and thickness of 5 pm Partial ground technique is implemented to improve the return loss and bandwidth of proposed antenna. This obtains bandwidth of 140, 700 and 410 GHz with return loss of -19.3, -29.2 and - 22.5 dB at resonant frequencies 2.5 THz, 4 THz, and 5.4 THz respectively. The proposed antenna has been fed by means of microstrip feed line having impedance of 50 Q. The results of antenna designed are suitable for THz applications. Higher Frequency Structural Simulator (HFSS v13) tool is used to simulate the proposed antenna.