Design of a Dualband Omnidirectional Planar Microstrip Antenna Array

Abstract

Abstract-This paper proposes and designs a new method of dualband omnidirectional planar microstrip antenna array. A cascade of transposed microstrip lines have been adapted to produce effective antenna structures that radiate omnidirectionally, with high efficiency, low reflection, and useful radiation patterns. In this paper, the antenna structure has been found to have low-pass characteristics due to the periodic discontinuities at the transposed junctions. The analysis and design of the low-pass characteristic are performed according to the filter theory of periodic structures and full-wave simulation. Therefore, a relatively higher frequency radiating array is appropriately designed with a low-pass filtering attribute, which prevents the lower frequency radiators from resonating at the relatively higher frequency. An air gap between adjacent transposed sections is proposed in order to enhance impedance matching, and a fork shape stub at the end is used as a virtual short point to enhance radiation at the higher frequency. Finally a single port dualband omnidirectional antenna array is obtained by locating the higher frequency radiating array with low-pass filtering attribute near the antenna feed and a relatively lower frequency radiating array at the end. An example of a dualband omnidirectional planar array is demonstrated experimentally, which operates at 2.32 ∼ 2.56 GHz and 5.65 ∼ 6.10 GHz with S 11 < −10 dB and a stable radiation pattern, and corresponding gains of 7.0 ∼ 7.6 dBi and 6.9 ∼ 7.9 dBi respectively.

Cylindrical Microstrip Array Antennas With Slotted Strip-Framed Patches

“…This topology is expected to be very suitable in view of the specific features needed for the patch current amplitude and phase distributions: when the E-vector of the excitation field is parallel to the slotted side of the patch, the radiation field has predominantly a linear polarization. It is worth mentioning that, to the knowledge of the authors, no slotted strip-frame patches of this kind have ever been used in printed planar or cylindrical antennas [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37]. It is clearly shown in this paper that slotted strip-frame patches are effective for cylindrical microstrip antenna arrays (CMAAs) fed by a cylindrical microstrip line.…”

Three Optimized Omnidirectional Microstrip Antennas (Oma) for Wlan Applications

“…One solution, which was considered in [11], is the design of an OMA antenna in each band and feeding them in series, which increases the whole antenna dimension. Another way is the optimization of antenna sections to radiate properly in both the frequencies.…”

“…Also, a number of design approaches have been proposed in the literatures for multi-band or wide-band omnidirectional antennas. A dual-band OMA has been proposed in [11]. In this antenna, the higher frequency radiation with low-pass filtering attribute is placed near the antenna feed and a relatively lower frequency radiating array at the end which increases the antenna dimension significantly.…”

Measurement Evaluation of the TGN Radio Channel Models Usefulness in Predicting Wlan Performance

“…The X variable represents the cross correlation between the transmitting and receiving antenna(s) and can be calculated using the transmitter correlation matrix R T x and the receiver correlation matrix R Rx by Equation (5).…”

“…At present, yet another WLAN generation is being strongly promoted, although still in the draft 3.0 stage accepted in May 2012, offering data rates up to 7.2 Gb/s, with the first equipment already available for purchase. Such a momentum could not be left unnoticed by the cellular technologies carriers, vendors as well as scientific communities [1][2][3][4][5][6]. Owing to its ubiquitous presence at the customers' premises and public institutions, WLAN is now recognized as a serious candidate serving as a technology for offloading the cellular 4th generation LTE (Long Term Evolution) system from a significant amount of the indoor-originated user traffic.…”