Search

This research constructs a 26 GHz waveguide slot antenna with decent gain. The application of millimeter-wave requires high bandwidth and gain to increase the traffic and users for millimeter-wave and 5G technology. The application of millimeter waves requires a high gain and bandwidth to achieve the requirements of traffic and users increasing for 5G technology and existing millimeter-wave. High-gain and power handling are provided by waveguide slot antennas. Three waveguide structures which are two waveguide antennae and a waveguide horn have been simulated by using CST and fabricated by a 3D printer. The tilt technique has been used with a waveguide to increase the bandwidth and gain of an antenna. A waveguide with broad wall tilt slots has one diction beam while a waveguide with broad and narrow wall tilt slots has two direction beams, each length of the wall enough to distribute six symmetric tilt slots. The gain of 14.3 dB and 1.9 GHz bandwidth are recorded for an antenna with broad wall tilt slots with one beam. While the waveguide with broad and narrow wall tilt slots achieved a gain of 13.9dB and a bandwidth of 1.9 GHz. The proposed antenna is a decent candidate for use with millimeter waves. [ABSTRACT FROM AUTHOR]

This paper focuses on the design of a multibeams antenna using waveguide slots technology at Xband. The multi-beams radiation is proposed to expand the coverage of the single antenna, thus more capacity is enabled. Waveguide slots antenna is a well-known antenna for high power and gain transmission capabilities. Therefore, it is preferred. In this work, four variations of waveguide slots antennas are studied. The slot distribution covers one to four broad and narrow walls of the waveguide. This technique enables multibeams patterns. The performance of the proposed antennas is simulated using CST microwave software. The simulated responses of the antennas show that a good matched with return loss greater than 10 dB at the desired frequency. The four proposed antennas achieved a good gain between 6.3 and 7.4 dB with directional beamwidth of 15 degree. The proposed antennas are suitable for implementing in radar applications. [ABSTRACT FROM AUTHOR]

This paper describes the development of a Fractal printed Yagi-Uda antenna for wireless local area network (WLAN) applications operating at 2.4 GHz frequency. In miniaturizing the dimensions of an antenna, fractal method is applied where the first iteration and second iteration is implemented. The Computer Simulation Technology (CST) software is used as the platform to design and simulate the antenna. The substrate material used is the FR-4 board which has a dielectric constant of 5.4, the thickness of 1.6 mm and tangent loss of 0.019. The antenna performance interm of the reflection coefficient, radiation pattern and gain are compared and analyzed. For the first iteration, 22.81% of reduction size has been achieved and 30.81% reduction of the antenna size for second iteration has been achieved. [ABSTRACT FROM AUTHOR]

In this paper, a simple method is proposed to diagnose the position of the damaged sensors. The position of the damaged sensors is diagnosed on the basis of the null depth level and the number of nulls for the degraded radiation pattern. The method is initiated with tabulation of the array radiation pattern with a single damaged sensor. The corresponding pattern is set as the reference to the radiation pattern of the failed sensors. The tabulated damaged array sensors are compared to a configuration of the assumed damaged sensor. The radiation pattern with deeper null depth level will be the location of the damaged sensor. Moreover, the symmetrical sensor damaged (SSD) technique diagnose the position of damaged sensor, in which on the basis of nulls one can detect the location of damaged sensors. The proposed method diagnoses the location of damaged sensors on the basis of pattern without complex computation as compared to available methods. [ABSTRACT FROM AUTHOR]

A novel frequency and pattern reconfigurable Yagi antenna is proposed. The antenna is formed by a driver, a reflector and two directors. The introduction of switches using a PIN diode at the arms of the driver element produces three switchable frequencies at 1.25 GHz, 1.85 GHz and 2.45 GHz. By controlling the switches at the directors and reflector, the radiation pattern can be configured to near omni-directional pattern or directional pattern at those three frequencies. Simulated and measured results are used to demonstrate the performance of the antenna. The simulated and measured return losses and the radiation patterns, are presented and compared. It was found that the gain of the antenna increases from 3.3 dB to 5 dB in a directional pattern, when compared to the near omni-directional pattern. [ABSTRACT FROM AUTHOR]

An innovative technique involving the usage of a mushroom Electromagnetic Band Gap (mEBG) structure with an ultra wideband (UWB) antenna is reported in this work. A single unit of mEBG lattice is incorporated within a novel UWB antenna to perform the band rejection operation. The antenna can be fixed to reject or reduce the transmit power for any band within the UWB spectrums of frequencies through a careful design of this mEBG structure, thus solving the problems concerning interference and reducing the requirements for complex filtering electronics within the UWB devices. [ABSTRACT FROM AUTHOR]

A textile artificial magnetic conductor (AMC) waveguide sheet with a textile diamond dipole is proposed to improve wireless on-body transmission. The sheet-like waveguide provides an independent transmission path which can reduce the performance degradation caused by the human body. The proposed AMC sheet is made entirely of textiles for both the substrate and the conducting parts, thus making it suitable for wearable communications. Transmission characteristics between antennas are studied rigorously in free space and on-body environments. Significant transmission enhancement is observed for all the tested orientations and positions for both free space and onbody placements. With the presence of the AMC, the S21 has peaks of up to a maximum of -9.9 dB. This textile AMC sheet constitutes a new approach for efficient wearable wireless body-centric communications. [ABSTRACT FROM AUTHOR]

Wideband-multiband reconfigurable elliptical monopole antenna is investigated in this paper. By having conventional elliptical monopole antenna, wideband operating frequency is obtained. With the combination of dual pairs of slotted arms and a band-pass filter on the ground plane of the elliptical monopole, multiband is achieved. Dual-band operating frequencies at 1.6 GHz and 2.6 GHz while wideband operates from 3.35 GHz to 9 GHz. Therefore, wide range of wireless communication systems is obtained from the proposed antenna to support the multiband mode (i.e. GPS and LTE) and UWB systems. Frequency reconfigurable is achieved by controlling the switches integrated on the antenna structure. Simulated results of reflection coefficient, radiation patterns and gain performance are presented. The proposed antenna design is suitable candidate for different wireless communication applications. [ABSTRACT FROM AUTHOR]