Soubhi Abou Chahine

A Smart Antenna Simulation for (DOA) Estimation Using MUSIC and ESPRIT Algorithms

In this paper we propose an approach to design a smart antenna system that uses six-port reflectometer. This is done to detect the DOA arrival angles of five incoming RF signals using MUSIC and ESPRIT algorithms. The characteristic of each algorithm are critical in the DOA precisions. The results are deduced from the simulation of the characteristics of the system, using the advanced design system (ADS) and MATLAB

Empirical Formulation and Design of a Broadband Enhanced E-Patch Antenna

A broadband probe-fed microstrip antenna with E-shaped patch on a single-layer air substrate is investigated. Bandwidth enhancement of the antenna is achieved by inserting two parallel slots into its radiating patch. The effects of the following design parameters: the slot length (Ls), width (Ws, position (Ps), the substrate height (h), and the position of excitation point (Xf, Yf) are analyzed, followed by an optimization procedure to select the optimum values for broad-band operation. The design parameters are empirically formulated as a function of the center frequency. Empirical equations are validated by simulation. Finally, a 41% Enhanced E-shaped patch antenna for modern wireless communications (PCS, DCS, UMTS, WLAN 802.11 b/g. and Bluetooth) is designed, simulated, fabricated, and measured. A comparison between simulated and measured results is also presented.

A Modified Circular Disc Monopole Ultra Wide Band antenna

In this paper we present a Modified Circular Disk Monopole Ultra Wide Band (UWB) antenna. The antenna covers a very large band from 1.5 to more than 15 GHz. The solution of this antenna consists in varying the radius of the patch and the ground dimensions. The proposed antenna designs and performances are analyzed using Ansoft High Frequency Structure Simulator (HFSS). The radiation characteristics are as expected for monopole antennas.

Reflectometer calibration without an open circuit

This paper presents a convenient calibration technique of a six-port reflectometer requiring a set of loads including two standards and avoiding the use of an open circuit. This method has been applied for different reflectometers at three frequencies: 2, 33, and 94 GHz. Reflection coefficient measurement results obtained by this method and other calibration techniques prove its efficiency. Transmission coefficient measurement has also been performed at 94 GHz. Characterizations of some coaxial components by the heterodyne network analyzer using this technique and other calibration methods are presented at frequencies between 0.5 and 10 GHz.

An active millimeter load-pull measurement system using two six-port reflectometers operating in the W-frequency band

An active load-pull measurement system using two six-port reflectometers operating in the W-frequency band is demonstrated. Ninety loads over the whole Smith chart have been synthesized and measured by both reflectometers. The maximum deviation between both measurement data is 0.02 for the magnitude and 3/spl deg/ for the phase of the reflection coefficient of the 90 loads. The constant power gain circles of a PHEMT operating at 89 GHz are shown and compared with those calculated from its S/sub ij/ scattering parameters. The deviation between the radii of circles is less than 0.03.

Performance comparison between six-port and five-port reflectometer

This paper presents a feasibility study for replacing six-port reflectometers by five-port reflectometers for vector measurements in microwave frequency bands. A new calibration technique is proposed for calibrating the five-port reflectometer. This procedure requires only a short circuit as a standard. The comparison of the practical results obtained by the five-port system with those measured by six-port reflectometers proves its efficiency.

A New Modified Circular Disc Dipole Antenna for Ultra-Wideband Systems

In this paper, we present a modified ultra-wideband (UWB) antenna for ultra-wideband applications such as Wireless Communication and WiMax systems. It consists of a two circular-disc patch fed by a 50 Omega coaxial feed line. The obtained bandwidth (SWR les 2) is about 10 GHz (from 0.650 to 10 GHz with a bandwidth ratio (1:15.4)). The radiation characteristics are as expected for dipole antennas.

The design and implementation of electrically small reconfigurable patch antennas

In modern times, a large part of communication equipment is getting smaller with a great need for power efficient and electrically small wireless devices. Wireless devices are not limited to one standard and can operate at multiple frequencies. The key characteristic of future generation wireless communication systems is the ability of antenna reconfiguration. Reconfigurable antennas are considered as a promising paradigm that can generate many modes using a single antenna structure. In this paper, the design and implementation of electrically small reconfigurable patch antennas is presented. Different designs are developed and simulated. The designed antennas are fabricated and tested. The performance of the fabricated antennas is evaluated and analyzed.

A low cost efficient reflectometer

This paper presents an efficient low cost reflectometer for microwave vector measurements using a four-port reflectometer with a single power detector. Two different systems are proposed to find the reflection and transmission coefficients. The system has been validated in two different frequency bands at 2 GHz and 94 GHz. The comparisons of measurement results with those obtained by the six-port technique prove the validity and the efficiency of this reflectometer.

Wide-band slotted flower PIFA antenna for multimedia handhelds terminals

The rapid progress in wireless communication systems and handheld terminal devices has made the implementation of small multi-band antennas one of the main technical challenges. The number of wireless systems in which multimode mobile terminals are required to operate has been growing constantly in recent years. Nowadays handheld terminal phones use various cellular bands (GSM850/900/1800/1900 + 3G/4G/5G), wireless LAN, Bluetooth, Digital TV (DVB-H), FM radio, GPS, RFID, UWB, and WiMAX The narrow bandwidth constitutes the major disadvantage of microstrip antennas in most practical applications. This study proposes a new wideband small size flower-shaped PIFA antenna. The PIFA design has newest flower structure and is supported by two or three shorting pins. The layer patch is slotted by Allah name in Arabic. A capacitive feeding of the antenna was done via 50 Ω coaxial cable to achieve impedance matching. The simulation was done using the high frequency HFSS10 simulator for different scenarios. Simulated results on the return loss, the radiation pattern, and the gain are promising. The devised antenna could be implemented in many wireless communication standards such as PCS (1850-1990 MHz), UMTS (1920-2170 MHz), WLAN 802.11 b/g (2400-2484 MHz), WIMAX (2.5-2.69 GHz), and WIMAX (3.4-3.6 GHz).