Substrate fields modulation with defected ground structure: A key to realize high gain, wideband microstrip antenna with improved polarization purity in principal and diagonal planes

Abstract

Rectangular microstrip patch antenna with circular headed dumbbell shaped defect in ground plane has been studied experimentally for concurrent improvement in its gain, bandwidth and polarization purity in principal and 458 diagonal planes. Around 9-9.5 dBi peak co polarized (CP) gain, 22% impedance bandwidth along with minimum 19-20 dB of CP-cross polarized (XP) isolation in both principal and 458 diagonal plane are achieved with the present structure. These observed improvements in results from present antenna are justified with physical insight. The present structure is simple and easy to manufacture. The geometry of the defect in ground plane has been shaped judiciously to modulate the fields beneath the patch efficiently for simultaneous improvement of the three parameters. Very close mutual agreement between simulation and measure results are revealed. The present investigation provides an insightful, visualization-based understanding of concurrent improvement of all these parameters. V C 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:174-181, 2016.

Wide bandwidth microstrip antenna with defected patch surface for low cross polarization applications

“…Now, apart from higher order orthogonal resonance TM 02 , the orthogonal component of the dominant mode TM 10 also play a key role for the generation of XP fields from a patch and is well‐analyzed in . The effect of orthogonal component of the dominant mode is exceptionally prominent near patch corners as discussed in the same literature.…”

“…A clear physical insight in to the observed improvement in XP radiation may also be extorted out from the distribution of electric field magnitude over the patch surface, which is depicted in Figure . The thorough literatures establish that, the main sources of XP are the radiation from nonradiating edges and patch corners of a RMA. Therefore, to reduce the radiation from nonradiating edges, we need to minimize the field magnitude there.…”

Arc-cornered microstrip antenna with defected ground structure for broad banding and improved cross-polarization suppression over whole skew planes

“…The completely pure polarization in all principal and other skew planes is very much required for several wireless communication systems and especially for array applications and polarization reuse purpose. Moreover, around 22% band width along with 9.5 dBi gain is apparent from the reported structure [16]. Around 22 dB of CP-XP isolation in the principal H-plane is apparent from [11], while it produces only 12 dB of CP-XP isolation in the 458 diagonal planes.…”

“…This in fact produces severe restrictions to the scientific community looking for such antennas with completely good polarization purity in all principal and other diagonal skew planes. The conventional RMA with circular headed dumbbell DGS has been investigated by the present authors [16] recently which shows around 19 and 16 dB of CP-XP isolation in the principal Hand 458 diagonal planes, respectively. In the above-mentioned literatures [11,14], the XP performances in the diagonal skew planes have been predicted with simulation results only and those are not supported by the measured data.…”

Miniature Planar Antenna Design for Ultra-Wideband Systems

“…Cross-polarization can be reduced by loading the shorting pins, which has been demonstrated for patch antennas [32][33][34][35]. The shorting pins are located in the centerline of a square patch to strengthen the surface current density near the feeding point at edge.…”