Design of a Corner-Reflector Reactively Controlled Antenna for Maximum Directivity and Multiple Beam Forming at 2.4 GHz

Abstract

Electronically steerable passive array radiator (ESPAR) antennas constitute a promising research field and are expected to play important role in future wireless communications. In this paper, a new approach in ESPAR antenna design for base station applications is proposed. A corner-plate reflector is combined with active and passive (reactively loaded) elements in order to implement a corner-reflector ESPAR (CR-ESPAR) configuration. It is shown that when combined with corner reflectors in order to sectorize the coverage area, an ESPAR antenna offers multiple radiation patterns with higher directivity and resolution. A case study of a CR-ESPAR suitable for 2.4 GHz ISM applications is demonstrated, where the performance of the structure is optimized with respect to resonance frequency, input impedance, and multiple switched-beam patterns configuration. The optimization of the array is performed using a Genetic Algorithm (GA) tool as a method of choice, achieving a maximum gain equal to 14 dBi for a 30 3 dB-beamwidth and a gain of 11 dBi for a 45 3 dB-beamwidth, while the VSWR is kept below 1.7 in all cases. Due to its limited physical size, the proposed CR-ESPAR can be used as a portable antenna for deployment in WiFi, WLAN and other applications.

A Novel Antenna System for Body Temperature Change Detection Appropriate for Multi-Channel Microwave Radiometry

“…In order to determine the range of the optimization parameters regarding the reactive loads, the matching network of a passive element was simulated using ADS by Agilent [18]. The configuration schematic of the matching network is illustrated in Fig.…”

“…5. The achieved passive element's reactive load ranges from −353j Ohm to 111j Ohm [18]. These values are used by the GA in order to generate realistic values for the optimization of the R-PIFA's matching networks.…”

A Pattern Correlation Decomposition Method for Analysis of ESPAR in Single-RF MIMO Systems

“…ESPAR-based MIMO systems have higher energy efficiency (EE) [5], [6] as compared to conventional MIMO transmitters due to the use of single RF chain [7]- [9]. To exploit the potential for increased EE, antenna designs for ESPAR for various wireless systems, including 4G and WiFi, have therefore been proposed [10]- [12]. Investigations into the practicality of ESPAR including the effect of quantizing the parasitic loads [13] and overcoming reductions in capacity resulting from mutual coupling [14], [15] have also been performed.…”

Customizing WLAN Access Point’s Indoor Coverage and Throughput with Corner Reflector

“…The corner reflector is an easyto-design reflector that could be easily incorporated with current Wi-Fi's A.P. [11]. Due to the nature of the corner reflector structure, a change in propagation coverage could be easily achieved through position-change of the reflector relative to the A.P.…”