Fitri Yuli Zulkifli

Mutual Coupling Reduction Using Dumbbell Defected Ground Structure for Multiband Microstrip Antenna Array

A novel design of multiband microstrip antenna array with dumbbell shape defected ground structure (DGS) is presented. The DGS is inserted into the ground plane between the two elements of the antenna array in order to suppress mutual coupling. Both simulation and measurement results verifled that the DGS improved the radiation properties of the antenna array. Measurement results of the DGS antenna showed mutual coupling reduction of maximum 5dB and gain enhancement to 3dB.

RADIATION PROPERTIES ENHANCEMENT OF TRIANGULAR PATCH MICROSTRIP ANTENNA ARRAY USING HEXAGONAL DEFECTED GROUND STRUCTURE

This paper presents a hexagonal shape defected ground structure (DGS) implemented on two element triangular patch microstrip antenna array. The radiation performance of the antenna is characterized by varying the geometry and dimension of the DGS and also by locating the DGS at specific position which were simulated. Simulation and measurement results have verified that the antenna with DGS had improved the antenna without DGS. Measurement results of the hexagonal DGS have axial ratio bandwidth enhancement of 10 MHz, return loss improvement of 35%, mutual coupling reduction of 3 dB and gain enhancement of 1 dB.

Dual band microstrip antenna using U and S slots for WLAN application

A dual band microstrip patch antenna for solution standard wireless local area network (WLAN) is presented. Dual band characteristic is produced by combining the 2.4 GHz band and the 5 GHz band by using slot U. Wideband characteristics is achieved at frequency 5 GHz by using slot S. This design can completely cover the IEEE standard (802.11 b/g and 802.11 a) for WLAN.

S-shaped Patch Antenna Fed by Dual Offset Electromagnetically Coupled for 5-6 GHz High Speed Network

Novel Design of S-shaped microstrip patch antenna fed by dual offset electromagnetically coupled to generate wideband operation in the 5–6 GHz frequency range is presented. It is demonstrated that by adding two slots opposite to each other to a rectangular patch and using dual offset electromagnetically coupled, wideband operation can be satisfactorily achieved. In advance, the two slots in the rectangular patch can reduce the area of the patch to 19.62%. Importantly, this antenna design is thin and small to be accommodated in a PCMCIA card of standard 5 mm thickness. DOI: 10.2529/PIERS060801042546

A compact multiband microstrip antenna using u and s slots

A triple band microstrip patch antenna for the WiMAX application has been designed, simulated, fabricated and tested. Both simulation and experiment shows similar results. The proposed antenna exhibits three bands, covering the 2.3 GHz (2.29-2.41 GHz), 3.3 GHz (3.29-3.40 GHz) and 5 GHz (5.28-5.90 GHz) as well as good radiation properties. Therefore this antenna is suitable for WiMAX application or other wireless applications that works in these frequencies.

A UWB antenna for microwave brain imaging

Brain tumor is one of degenerative diseases that have been concerned by doctors and researcher to be investigated. MRI, PET, or CT is widely used modalities for brain tumor scanning, which it can provide accurate and high resolution image. However, it costs still relatively high particularly in developing countries with high population like Indonesia. Hence, it is desirable to develop a new brain tumor imaging system that is affordable, easy to operate (portable), non-ionization (safe radiation) and use a non-invasive technique. Microwave imaging is considered as a suitably matched modality to those requirements. In this paper, an ultrawideband (UWB) antenna is proposed as a transceiver of microwave imaging on brain tumors, which it operates in UWB range (i.e. 3.1-10.6 GHz). The proposed antenna is a printed dipole-like fed by a coplanar waveguide because it provides high frequency response. The antenna is numerically simulated using C ST Microwave Studio 2014 and experimentally measured near to a semi-solid head-equivalent phantom, particularly S11 and radiation pattern on xy- and yz-plane at 5.8 GHz.

Improved Design of Triangular Patch Linear Array Microstrip Antenna Using Isosceles-Triangular Defected Ground Structure

A novel isosceles-triangular defected ground structure (DGS) is implemented on Triangular Patch Linear Array microstrip antennas to suppress surface waves and improve the design. The radiation performance of the antenna is characterized by the dimension of the DGS and by locating the DGS at specific position which is found experimentally. Measured results shows that the antenna with DGS can improve impedance matching with better return loss of -45.48 dB from -30.33 dB, bandwidth enhancement (2.87 MHz), gain enhancement upto 0.5 dB and suppress cross polarization.

A simple folded dipole antenna for medical implant communications at 900 MHz band

Nowadays, implanted medical devices that are using inductive coupling for communication, cannot be used for transmitting medical data in several meters range. This triggers us to study about implantable device systems in order for communications is enabled to be longer range by transmitting wirelessly electromagnetic signal. In this system, the external devices such as home monitoring device or portable equipment will provide the patient more mobility, and the patient or the health care provider could benefit from timely and ease of access to important patient medical information via a networked connection. Due to such advantages, small antennas for implantable devices are very important components in monitoring systems to provide wirelessly communication between a patient and an access point. This paper proposes a simple structure of a folded dipole antenna for an implantable device aimed at wireless patient monitoring applications. The implantable device is assumed to be used with a syringe injection, so the device can be simply embedded into the human body. The antenna is operated in UHF band 924 MHz, which is band of Indonesian frequency allocation for RFID applications. The antenna is small enough in this band with good performances such as S parameter, impedance bandwidth, radiation pattern and gain. The antenna has enough gain for more than 10m range communication with 250 MHz bandwidth (VSWR ≤ 1.5).

Multiband microstrip antenna array for WiMAX application

A compact multiband microstrip antenna array for WiMAX application has been proposed and studied by simulation and experiment. The simulation and measurement results showed a multiband characteristic of the proposed antenna was achieved. Radiation patterns of the multiband antenna was measured.

Evaluation on microwave imaging system by using ultrawideband antenna

We are developing a microwave imaging system that is affordable, easy to operate (portable), non-ionization (safe radiation) and non-invasive. In this paper, a microwave imaging system using UWB printed dipole-like antenna based on back-projection algorithm is proposed at frequency of 5.8 GHz aimed at tumor imaging system in order to obtain a reconstructed image. The evaluation is experimentally conducted against to a semi-solid two-layer phantom for imitating normal and tumor tissue. The reconstructed image is successfully obtained and analyzed on its typical pixel histogram.