International Journal

A novel microstrip low-pass filter (LPF) using radial patched resonator and modified T-shaped resonators is designed to achieve ultra-wide stop-band. Also, the designed LPF has successfully addressed the problems of compactness and insertion loss, simultaneously. LC equivalent circuit of the proposed filter is calculated and equation for the sharpness in transition band is obtained based on LC equ

A novel tri-band asymmetric slot with defective ground structure (DGS) microstrip antenna for dual circular polarization (CP) is proposed. By placing a slot with 45° across diagonally at the center of the patch, excites resonant bands with narrow bandwidth and dual CP operation. The main design challenge is to introduce optimized defected element of circular dumbbell shape to enhance the impedance

Since a conventional microstrip patch antenna is inherently a narrowband radiator, stacked-patch antennas are commonly used either to enhance the bandwidth or to achieve multi-band characteristics. However, the stacked patch structure has a number of geometrical variables which need to be optimized to achieve the desired characteristics. The conventional design procedure involves repeated costly a

A novel asymmetric ?+? shaped fractal slotted circularly polarized microstrip antenna with a Yagi?Uda structure is proposed. Four asymmetric plus shape slots are embedded symmetrically in the center of all four quadrants of a square patch. To suppress undesirable higher modes, dumbbell-shaped defected ground structure (DGS) is introduced at the ground layer of the antenna. We introduce a method to

A novel compact asymmetric coplanar strip fed planar antenna with defected ground structure and defected microstrip structure for dual band application is presented. The proposed antenna is composed of defect in both ground plane and radiating strip. The antenna has an overall dimension of 21 × 15.35 × 1.6 mm when printed on a substrate with dielectric constant of 4.4 and loss tangent of 0.02. The

A wideband orthogonally slot cut annular ring microstrip antenna fed by L-shaped probe is investigated using modal expansion cavity model and circuit theory approach. Simulation of the proposed antenna is performed using and simulated results are compared with the measured and theoretical results. The impedance bandwidth of about 37.46% is observed at resonant frequency 3.15 GHz. The proposed ant

This paper analyses the effects of receiver non-linearity on the performance of the most commonly utilized signal detectors in cognitive radio systems. The analysis covers both self-modulation products of a single orthogonal frequency-division multiplexing (OFDM) signal and intermodulation IM products of two OFDM signals, and also their contribution to the probability of false detections. As a res

Directional modulation (DM) is an emerging technology for securing wireless communications at the physical layer. This promising technology, unlike the conventional key-based cryptographic methods and the key-based physical layer security approaches, locks information signals without any requirements of keys. The locked information can only be fully recovered by the legitimate receiver(s) priory k