Stripline Antenna Array for Local Information-Telecommunication Radio Networks F. F. Dubrovka and S. E. Martynyuk National Technical University of Ukraine “Kyiv Polytechnic Institute”, Kyiv, Ukraine Received in final form September 10, 2008 Abstract—There are represented results of theoretical and experimental researches of stripline antenna array for local information-telecommunication radio networks of IEEE 802.11b, g and IEEE 802.16 standards, which use radio frequency band 2.3…2.7 GHz. Antenna array consists of 4 (2´2) irradiators, which are excited with help of non-symmetric strip line with air fulfillment. Irradiators are two-resonator strip elements, made from thin metallic plate and fixed over the screen by means of metallic pins. Lower strip resonator elements are realized together with strip line. This approach to antenna array development allows to abandon the application of dielectric SHF substrates and hence, to reduce ohmic loss in the antenna and reduce its cost. DOI: 10.3103/S0735272709080093 Microstrip irradiators and antenna arrays (AA), built on a basis of them, are widely used in different radio systems during last two decades [1]. Their advantages in comparison with waveguide irradiators are their compact size, fabricability, and low net cost. Essential drawbacks of classical microstrip lines are their narrow operating frequency band and comparatively small input power. Therefore, microstrip antennas researchers and developers attention is paid to searching of more wideband configurations or antennas dimensions reducing with purpose of their application of two- or three-band mobile terminals. It is known, that essential widening of operating frequency band of microstrip irradiators can be achieved by dielectric substrate thickness widening, application of dielectric with permittivity close to unity [2], or slots cutoff in metallic part of strip resonators [3]. In paper [4] it is proposed a multi-layer configuration of microstrip antenna on a basis of two coupled resonators with different length, which are located one over another, with operating frequency band about 30%. The main drawback of the structure [4] is necessity of several dielectric substrates with different permittivity and thicknesses, a part of them are must be with double-sided metallization. Moreover, commercial fabrication of multi-layer AA, as a rule, is connected with a problem of provision of delicate microstrip structure protection from mechanical and atmosphere influences, that leads to essential cost increase. In paper [5] they propose to use three-dimensional strip structures with air fulfillment, and they achieve 90% of operating frequency of single strip irradiator, calculated per one linear polarization. Though, in spite of uniqueness of obtained results for frequency band, complication of mechanically stable AA construction on a basis of three-dimensional strip structures restricts essentially this approach value. The purpose of this work is research of irradiation characteristics and matching of mechanically rigid planar four element AA, consisting of wideband two-resonator strip irradiators with air fulfillment, which is acceptable for operation in local telecommunication networks of IEEE 802.11b,g and IEEE 802.16 standards. Geometry of proposed stripline AA with air fulfillment is shown in Fig. 1. In Fig. 1a, b there are shown three-dimension and vertical views, correspondingly. Construction basis and a screen of AA is metallic plate with dimensions 205´205 mm (1 in Fig. 1, 2). Plane strip structure of complex configuration 2, which is metallic (aluminum) sheet with thickness of 0.5 mm, is fixed in parallel over the basis by means of eight metallic cylinder pins 3. Like AA construction on a basis of classical microstrip technology, this structure combines realization of several functions. It contains input non-symmetrical line with wave resistance of 50 W, three reactive power dividers 5 for parallel power wiring for 4 (2´2) two-resonator strip irradiators and lower strip rectangular resonators of these irradiators. Irradiator’s centers are located at the same distance both in E- and H-planes. Strip lines feed irradiating resonators pairwise from opposite sides. To provide co-phase irradiations of AA elements additional segments are placed, so they compensate phase shift on 180 degrees at the central frequency of operating frequency band 2.45 GHz. To shape two-resonator irradiators 445 ISSN 0735-2727, Radioelectronics and Communications Systems, 2009, Vol. 52, No. 8, pp. 445–448. © Allerton Press, Inc., 2009. Original Russian Text © F.F. Dubrovka, S.E. Martynyuk, 2009, published in Izv. Vyssh. Uchebn. Zaved., Radioelektron., 2009, Vol. 52, No. 8, pp. 67–73.