M. T. Islam

Slot Loaded Circular Microstrip Antenna with Meandered Slits

A novel compact dual-frequency microstrip antenna is achieved by embedding two parallel slots to the radiating edges and insetting slits at the non-radiating edges. The proposed antenna exhibits dual-frequency band behavior operating at 867 MHz and 2.45 GHz suitable for UHF and microwave RFID application. The slot loading effect has been studied and evaluated. The two desired frequencies are tunable with frequency ratio of 2.66 to 2.95 by varying the meandered slit length. A good agreement is obtained between the simulated results and experimental results.

Curve Fitting Based Particle Swarm Optimization for UWB Patch Antenna

An optimization technique for microstrip patch antenna using Curve Fitting based Particle Swarm Optimization (CFPSO) is presented in this paper. An E-H shaped patch antenna designed using conventional optimization technique for Ultra Wide Band (UWB) communication is utilized to demonstrate the optimization technique. The conventional optimized antenna is designed by searching an acceptable solution from amongst the invariably huge collective range of geometry variables. The data for curve fitting is obtained from EM simulator by varying different geometrical parameters of the antenna. Using the data, the equations representing the relationship among different parameters of a microstrip antenna are generated. Curve fitting software was used to generate the curve. The CFPSO program was developed and executed in MATLAB. Conventionally optimized antenna is compared with CFPSO optimized antenna in this paper. The result yields that CFPSO showed remarkable improvement over bandwidth. For the E-H shaped antenna, the bandwidth is increased by 27% compared to conventionally optimized antenna.

Microstrip Antenna Design for Femtocell Coverage Optimization

A mircostrip antenna is designed for multielement antenna coverage optimization in femtocell network. Interference is the foremost concern for the cellular operator in vast commercial deployments of femtocell. Many techniques in physical, data link and network-layer are analysed and developed to settle down the interference issues. A multielement technique with self-configuration features is analyzed here for coverage optimization of femtocell. It also focuses on the execution of microstrip antenna for multielement configuration. The antenna is designed for LTE Band 7 by using standard FR4 dielectric substrate. The performance of the proposed antenna in the femtocell application is discussed along with results.

Performance investigation of a uni-planar compact electromagnetic bandgap (UC-EBG) structure for wide bandgap characteristics

A simple uni-planar EBG structure with reduced cell size is proposed for lower frequency band operation. The simulations of the design are performed using finite element method. Directive transmission method is applied to compute the bandgap of the EBG. The compact EBG structure exhibits wide stopband with different type of substrate materials. From the reflection and transmission characteristics the maximum bandgap obtained is 2.57 GHz (56.8%) and the best mutual coupling reduction level is -90 dB. The planar design can be easily fabricate on regular PC board and suitable for wide range of compact applications.

Development of a Multiband VHF Antenna for Low-Frequency Transient Radio Telescope

Low-frequency radio astronomy has become a fascinating research area in the field of astronomy, including on its instrumentation development. In this paper, a multiband VHF antenna for low-frequency transient radio telescope is developed. The multiband has been achieved by combining V-shape half-wavelength dipole, traps, and parasitic elements. Measurement result shows that the antenna can work properly in three different frequencies designated by International Telecommunication Union (ITU) for radio astronomical purposes.

Quad Band Handset Antenna for LTE MIMO and WLAN Application

A compact quad band antenna for long-term evolution (LTE) MIMO and WLAN application in the handset is presented in this paper. The proposed antenna comprises two symmetrical quarter wavelength radiating strips and a slotted ground plane. On the ground plane, a T-shaped slot is cut from the bottom. Two symmetrical P-shaped slots are etched at both sides of the ground plane. The radiating strips and slots generate a lower resonant at 780u2009MHz and an upper resonant at 2.350u2009GHz to cover LTE 700 Band 14, LTE 2300, 2.4u2009GHz WLAN, and LTE 2500. A novel isolation technique by placing a rectangular patch between the radiating strips is presented. The rectangular patch creates a dedicated current path for each radiating strip. The proposed antenna has high isolation of less than −18u2009dBi at LTE 2300, 2.4u2009GHz WLAN, and LTE 2500 band.

Post-IFFT-Modified Selected Mapping to Reduce the PAPR of an OFDM System

Orthogonal frequency-division multiplexing is now one of the most important modulation techniques due to its advantages. Despite its ability to overcome the equalization problem, multipath fading channels, and other issues, this system has a serious problem concerning the high output peaks with respect to the average power, which is called the peak-to-average power ratio (PAPR). Selected mapping (SLM), partial transmitted sequence, and amplitude clipping and filtering are some efficient methods to reduce the PAPR. In a previous work, we slid a single-phase rotation vector on the data sequence in the frequency domain to reduce the PAPR and the complexity compared to the conventional SLM. In this paper, we present a novel method that utilizes the same approach of our previous work, but it processes the data after the inverse fast Fourier transform block (time-domain operations) using a modified version of the SLM scheme, which has less computational complexity than the conventional one. The mathematical derivations and the simulation results show that the PAPR, the computational complexity, and the side information were reduced significantly by the proposed method.

A compact triangular shaped microstrip patch antenna with triangular slotted ground for UWB application

This paper is aimed to present a very small sized patch antenna for UWB applications. The antenna used microstrip feed-line. This antenna is very small in dimension. The total size of the antenna is 20×18mm2. Triangular slots in the partial ground plane, are used to get a better bandwidth. The antenna has VSWR<2 over the bandwidth. The whole designing and simulation process of the antenna is done by CST Microwave Studio software.

Analysis of Glass-Reinforced Epoxy Material for Radio Frequency Resonator

A radio frequency (RF) resonator using glass-reinforced epoxy material for C and X band is proposed in this paper. Microstrip line technology for RF over glass-reinforced epoxy material is analyzed. Coupling mechanism over RF material and parasitic coupling performance is explained utilizing even and odd mode impedance with relevant equivalent circuit. Babinets principle is deployed to explicate the circular slot ground plane of the proposed resonator. The resonator is designed over four materials from different backgrounds which are glass-reinforced epoxy, polyester, gallium arsenide (GaAs), and rogers RO 4350B. Parametric studies and optimization algorithm are applied over the geometry of the microstrip resonator to achieve dual band response for C and X band. Resonator behaviors for different materials are concluded and compared for the same structure. The final design is fabricated over glass-reinforced epoxy material. The fabricated resonator shows a maximum directivity of 5.65u2009dBi and 6.62u2009dBi at 5.84u2009GHz and 8.16u2009GHz, respectively. The lowest resonance response is less than −20u2009dB for C band and −34u2009dB for X band. The resonator is prototyped using LPKF (S63) drilling machine to study the material behavior.

28/38GHz dual band slotted patch antenna with proximity-coupled feed for 5G communication

This paper presents a slotted-rectangular patch antenna with proximity-coupled feed operated at dual band of millimeter-wave (mmV) frequencies, 28GHz and 38GHz. The antenna was built in multilayer substrate construct by 10-layers Low temperature Co-fiber Ceramic (LTCC) with 5 mils thickness each. The slotted-patch and thick substrate are configured to enhance the bandwidth and obtain a good result in gain as well. The bandwidth using are 21.3% at 28GHz and 13.0% at 38GHz with the direction gains are 8.63dBi and 8.62dBi at 28GHz and 38GHz respectively.