Design Of Log-periodic Dipole Array Research Articles

Tri-Objective Compact Log-Periodic Dipole Array Antenna Design Using MOEA/D-GPSO

Considering the defects of particle swarm optimization (PSO) and multi-objective evolutionary algorithm (EA) based on decomposition (MOEA/D), this article proposes an improved multi-objective EA MOEA/D-GPSO for compact log-periodic dipole array (LPDA) design. MOEA/D-GPSO decomposes multiple objectives into a number of single-objective optimization problems. Each particle deals with one sub-problem. All the particles are divided into a few groups, and each particle has several neighboring particles. During the search, a new solution is constructed by learning information from the random non-dominated solutions found by its own neighbors and group. ZDT instances have been introduced to verify the effectiveness of MOEA/D-GPSO with respect to other outstanding multi-objective EAs. Further, two miniaturized LPDA designs for the application of digital video broadcasting-terrestrial (DVB-T) (470–790 MHz), a tri-objective compact LPDA, and a novel LTE800-refused compact LPDA, respectively, are presented, showing their good performance over other similar designs and promising prospect of the proposed algorithm for high-dimensional and multi-functional LPDA design.

A Novel Nonlinear LPDA Design for HF Direction Finding

A novel design of log-periodic dipole array (LPDA) for high-frequency direction finding (DF) is presented. The traditional Carrel method employs fixed values of scale factor and spacing factors in LPDA designs. Here, we propose a design method which uses the continuous change of both the scale factor and the spacing factor so that the length of the dipoles and the space between dipoles vary nonlinearly. One advantage of our design is that the effective distance between the phase center position and the feed point of LPDA can be increased. So the effective radius of the circularly disposed antenna array (CDAA) composed of LPDA is extended, which is important for improving the accuracy of the DF system. Both the simulation and measurement results show that the proposed LPDA achieves larger effective distance and higher gain compared to that using the traditional Carrel method. The proposed LPDA also shows characteristics of wideband impedance matching. The antenna has been successfully applied to practical HF direction finding system.

Optimal LTE-Protected LPDA Design for DVB-T Reception Using Particle Swarm Optimization With Velocity Mutation

A near-optimal design of a log-periodic dipole array (LPDA), suitable for digital video broadcasting-terrestrial (DVB-T) reception (470–790 MHz), is presented. The LPDA is required to provide low standing wave ratio as well as high-gain radiation pattern with sufficient gain flatness over the entire passband, and concurrently achieve low gain for frequencies above 800 MHz to reject LTE800 signals and thus improve the reception quality in the DVB-T band. All the above requirements are better satisfied by applying a novel particle swarm optimization (PSO) variant, called PSO with velocity mutation (PSOvm). PSOvm induces mutation on the velocities of those particles, which are unable to improve their fitness. As shown in this paper, PSOvm comes closer to the above requirements compared to four well-known optimization methods and outperforms the traditional LPDA design method proposed by Carrel. The LPDA geometry chosen for optimization is not the conventional one, and therefore the dipoles are not considered to be included inside a specified angle as proposed by Carrel. Thus, the dipole lengths and distances as well as the boom dimensions are independently optimized. The PSOvm-based LPDA sufficiently meets all the above requirements and thus is suitable for DVB-T reception without the use of an external LTE-band rejection filter.

Research on Miniaturization of Log-periodic Dipole Arrays Using Folded Dipole

Log-Periodic Dipole Array (LPDA) is an ultra-wideband antenna with frequency-independent properties. It is widely used in radar, electronic warfare and other fields. Through summarizing the predecessors’ LPDA design theory, A LPDA operating in 1GHz ∼ 10GHz was proposed in this paper. A miniaturization method was presented by folding the dipole of low frequency. Compared with the original antenna, the miniaturized antenna reduced the lateral size by 25%. Meanwhile, the S11 parameter is less than -10dB in the operating band. And gain about 5 dB can be obtained in the same frequency band.

Design and Simulation of a Wide-Band LPDA<sup></sup>

A reconfigurable wideband Log-Periodic Dipole Array (LPDA) is here in introduced. Built utilizing low cost it can cover frequencies from 0.2GHz to 2GHz, through the discrete adjustment of its elements. The gain of antenna in a given frequency band of operation can also be changed by the reconfiguration of its elements. The design, construction and testing processes are discussed and a performance analysis is made based on computer simulations. In this paper simulation software HFSS is used to get the optimization design of LPDA, and the simulation results are agree with the experimental dates appropriately.

Genetic Algorithm Optimization of Log-Periodic Dipole Array

Th is paper presents Genetic A lgorith m (GA) optimization of Log-Periodic Dipole Array (LPDA). Considering the fact that, an LPDA can effectively be used for different wireless communication systems such as WiMAX, GSM-I, GSM-II and WiFi, respectively. GA optimization is applied to the physical size of the antenna and on its gain. The proposed design is compared with the conventional LPDA design in terms of length, diameter and spacing between the dipole elements. Presented results show that, the proposed optimization approach can significantly imp rove the antenna gain and reduced its size. The size of the antenna is reduced up to 12% as compared to the conventional design. Also, the gain is imp roved fro m 9.1, 9.5, 9.2 and 8.5 d B to 10.7, 11.2, 9.9 and 9.1 d B for the desired co mmun ication bands. The reduction in size and increment in gain make LPDA an attractive choice for wireless applications.

Application of bacteria foraging algorithm in designing log periodic dipole array for entire UHF TV spectrum

In this article, an attempt has been made to revisit the design of well-established log periodic dipole array (LPDA) in light of recent optimization technique, the bacteria foraging algorithm (BFA). Although there are many works published in the literatures based on various optimization techniques, this article deals with the optimization of the LPDA for the entire ultra high frequency (UHF) television (TV) spectrum (470–870 MHz) covering 400 MHz bandwidth and accommodating 49 channels. The challenges of this design lie in selecting suitable values of τ and σ for 134 frequency points for which different sets of all the output parameters such as gain, input impedance (Zin), front-to-back ratio (FTBR), first side lobe level (FSLL), voltage standing wave ratio (VSWR), and so forth are obtained and then averaged over to get Gainav, ZinAav, FTBRav, FSLLav, and VSWRav close to the desired values. These average values are used to design suitable fitness function. Another important aspect of this article is to provide exhaustive design details for LPDA using network theory that would couple to the BFA for getting the optimized number of elements to satisfy the desired values of Zinav, Gainav, FTBRav, FSLLav, and VSWRav, set as 50 Ω, 9 dBi, 40 dB, 40 dB, and 1.1, respectively. Moreover, this LPDA design considers the standard wire gauge dipole elements, which is just a very practical approach in the design procedure. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2013.