Ayman Elboushi

Dense Dielectric Patch Array Antenna With Improved Radiation Characteristics Using EBG Ground Structure and Dielectric Superstrate for Future 5G Cellular Networks

In this paper, a new dense dielectric (DD) patch array antenna prototype operating at 28 GHz for future fifth generation (5G) cellular networks is presented. This array antenna is proposed and designed with a standard printed circuit board process to be suitable for integration with radio frequency/microwave circuitry. The proposed structure employs four circular-shaped DD patch radiator antenna elements fed by a 1-to-4 Wilkinson power divider. To improve the array radiation characteristics, a ground structure based on a compact uniplanar electromagnetic bandgap unit cell has been used. The DD patch shows better radiation and total efficiencies compared with the metallic patch radiator. For further gain improvement, a dielectric layer of a superstrate is applied above the array antenna. The measured impedance bandwidth of the proposed array antenna ranges from 27 to beyond 32 GHz for a reflection coefficient (S11) of less than -10 dB. The proposed design exhibits stable radiation patterns over the whole frequency band of interest, with a total realized gain more than 16 dBi. Due to the remarkable performance of the proposed array, it can be considered as a good candidate for 5G communication applications.

High-Gain Hybrid Microstrip/Conical Horn Antenna for MMW Applications

A high-gain slot-coupled circular patch antenna with a surface-mounted conical horn for millimeter-wave (MMW) applications at 31 GHz is proposed. The design adopts microstrip/conical horn hybrid technology for a 6-dB enhancement over the conventional circular patch antenna. The overall antenna gain is about 12 dB, which makes it suitable for MMW imaging applications and short-range communications. A slot feeding mechanism is used for exciting the microstrip patch dominant mode TM010. The proposed design has been verified by simulations and finally confirmed by measurements.

Four-element dual-band printed slot antenna array for the future 5G mobile communication networks

In this article, a four-element dual-band printed slot antenna array for the future fifth generation (5G) mobile networks is proposed. The antenna element has a compact with size of 0.8 λ0 × 0.75 λ0 at 28 GHz. The simulated results show that the designed antenna has a dual-band function at 28/38 GHz that covers future 5G applications. The designed 1-to-4 modified Wilkinson power divider is used to feed the proposed array. For further enhancement of the designed power divider, an electromagnetic bandgap (EBG) structures are used. The proposed antenna array provides directional patterns, relatively flat gain, and high radiation efficiency through the frequency band excluding the rejected band.

A new circularly polarized high gain DRA millimeter-wave antenna

Millimeter-Wave technology is considered as an innovative solution for the next generation of the wireless networks and for short distance data transfer between electronic devices. It allows high data transfer rates “expected to be between 40–400 faster than 802.11n wireless networks”. However, Millimeter-wave communications at frequencies around 60 GHz suffer from high propagation losses due to absorption by oxygen molecules in the atmosphere [1]. Accordingly, improving the gain is considered as one of the most important targets in antenna design for such frequencies. Also, in order to overcome multi-path, improper line-of-Sight between the transmitter and the receiver and some phasing issues due to rain or snow in the air a circular polarized antenna is required to assure high quality transmission or reception. Recently, many different types of antennas are being investigated [2]-[4] for working in mm-wave applications such as (wireless LANs, Microwave imaging and hidden objects detection). For realizing such antennas different technologies are proposed including hybrid DRA antennas [2]-[4], stacked antennas [5] and SIW antennas [6]. In this paper, we present a novel DRA/Microstrip hybrid high gain and circularly polarized antenna for MMW applications. It consists of a printed rectangular patch with a shaped corners and a hollow rectangular DR radiator works together as a single antenna element fed by a rectangular aperture in the ground plane.

New dense dielectric patch array antenna for future 5G short-range communications

In this paper, new dense dielectric (DD) patch array antenna prototype operating at 28 GHz for the future fifth generation (5G) short-range wireless communications applications is presented. This array antenna is proposed and designed with a standard printed circuit board (PCB) process to be suitable for integration with radio-frequency/microwave circuitry. The proposed structure employs four circular shaped DD patch radiator antenna elements fed by a l-to-4 Wilkinson power divider surrounded by an electromagnetic bandgap (EBG) structure. The DD patch shows better radiation and total efficiencies compared with the metallic patch radiator. For further gain improvement, a dielectric layer of a superstrate is applied above the array antenna. The calculated impedance bandwidth of proposed array antenna ranges from 27.1 GHz to 29.5 GHz for reflection coefficient (Sn) less than -1OdB. The proposed design exhibits good stable radiation patterns over the whole frequency band of interest with a total realized gain more than 16 dBi. Due to the remarkable performance of the proposed array, it can be considered as a good candidate for 5G communication applications.

MMW Sensor for Hidden Targets Detection and Warning Based on Reflection/Scattering Approach

An antenna sensor for millimeter wave (MMW) hidden target detection and warning applications is introduced. The sensor consists of three adjacent high gain microstrip/horn hybrid antenna elements. The central antenna acts as bi-static radar, while the two side antennas are used to receive the scattered back signals from a hidden object. The proposed antenna sensor has been employed in a detection/imaging system prototype based on time domain reflectometry (TDR). A very short pulse generated by a vector network analyzer is used to illuminate a three layers body model made from cotton, natural leather and reinforced papers. The model construction is chosen to emulate the presence of human body. Experimental scanning of a hidden metallic target has been conducted for three different orientations of the target. Compared to a single antenna sensor, the triple sensor shows a great enhancement in the detection ability and the constructed image resolution of a hidden target.

4-elements MMW array with EBG feeding network

A broadband and high gain 4-elements Ka-band tapered slot antenna (TSA) array with an EBG feeding network is presented. The EBG feeding structure is designed to suppress the surface waves causing unbalanced power division and undesired mutual coupling between the output ports. The array design parameters are tuned to achieve a 20 dB gain at 30 GHz, and an impedance bandwidth covers the entire ka-band. The array exhibits a constant gain and a stable radiation pattern over the operating band which makes it suitable for millimeter-wave short distance wireless communications and imaging applications.

STUDY OF ELLPITICAL SLOT UWB ANTENNAS WITH A 5.0{6.0 GHz BAND-NOTCH CAPABILITY

Two microstrip fed ultra-wideband (UWB) antennas with difierent band rejection techniques are presented in this paper. The designed antennas consist of a defected ground plane with an elliptical slot and two difierent radiator shapes. The flrst design is composed of a half circular ring radiator element while the second one uses a crescent shaped radiator. The radiators are fed by a 50› microstrip line with a tapered microstrip transition to ensure good impedance matching. The calculated impedance bandwidth of the proposed antenna ranges from 3GHz to 14GHz with relatively stable radiation patterns. To achieve band-notch characteristic in the 5.0{6.0GHz WLAN frequency band, two difierent techniques have been implemented. The flrst technique uses a C-shaped slot etched in the ground plane while the other one uses another C-shaped slot in the feed line.

Circularly-polarized SIW slot antenna for MMW applications

A novel low profile circularly polarized antenna using Substrate Integrated Waveguide technology (SIW) for millimeter-wave (MMW) application is proposed. The antenna employs an X-shaped slot excited by a rectangular SIW and backed by circular cavity. The optimized design has an operating frequency range from 34.7 GHZ to 36.1 GHz with a bandwidth of 4.23%. The overall antenna realized gain is around 6.7 dB over the operating band. The simulated results using both HFSS and CSTMWS show a very good agreement between them.

B14. Active millimeter-wave imaging system for hidden weapons detection

In recent years, the need for developing an accurate human body imaging systems for concealed weapons becomes urgent due to the increase of the international terrorism. In this paper, an experimental system for hidden weapons detection is introduced. The system is based on the principles of Synthetic Aperture Radar (SAR) and monostatic radar. The proposed system transmits a very short pulse generated by a vector network analyzer (VNA) to illuminate a three layers target made from jeans, natural leather and reinforced papers. The target construction is chosen to emulate the presence of the human body. The imaging process is carried out by interpolating successive time domain measurements of the probe reflection coefficient S11 at different points. Two types of scanning probes are used the first one is a standard millimetre-wave (MMW) horn antenna while the other one is a hybrid microstrip/horn antenna. The system shows a great ability for imaging and detecting a hidden metallic targets under the jeans layer of the target.