29 research outputs found
Antenna Design for Ultra Wideband Application Using Stacked Multiresonator Patches
As wireless communication applications require more and more bandwidth, the demand for wideband antennas increases as well. For instance, the ultra wideband radio (UWB) utilizes the frequency band of 3.1-10.6 GHz .This paper presents some of the work carried out within ULTRAWAVES in the area of antenna design and analysis. Two antennas have been designed, optimized and simulated using Stacked Multiresonator patches. In addition results and conclusions are presente
Effect of Substrate Scaling on Microstrip Patch Antenna Performance
The Maxwell field equations (MFEs), as ecumenical model of electromagnetic phenomena, are scale-invariant under Lorentz Transformation (LT). To apply LT, some considerations are required which are not all practically available or technologically attainable; hence, the scale-invariant feature may not be reached effectively. Paving the way to focus on this issue, the effect of substrate thickness scaling as an uncontrollable parameter, is explored on eight identical patch antennas with different substrate thicknesses. In this way, the resonant frequency and complex value of return loss are measured. The effect of manufacturing tolerances of dielectric thickness on resonant frequency deviation and return loss magnitude are carefully studied, too. Also the unwanted distortive effect of selected electrical connection, say as a female SMA connector, is investigated at higher frequencies. The obtained results are comparatively analyzed which confirm the practical bottlenecks in meeting the antenna parameters scaling
A Compact Array Antenna: Explicit Design for C and X Band Applications
A novel and compact design of a circularly polarized slot antenna (CPSA) is elaborated. With the aim of generating CP feature and enhancing the impedance bandwidth, four rectangular stubs are wisely embedded in the antenna feed line structure and slotted ground plane to excite two orthogonal E vectors. Subsequently, a suitable arrangement of CPSAs in the form of 2 × 2 and 4 × 4 array antennas provokes higher functionalities in C and X band applications, respectively. Sequentially rotated (SR) feed technique is adopted to excite the antenna structure in array configurations. Measured and simulated results confirm outperformance of the array antennas with respect to the previously proposed designs. Compact size, wider impedance and axial ratio (AR) bandwidth, higher gain, and suitable radiation characteristics, both in single and array configurations, confirm suitability of the proposed designs for communication systems
Dual-band magneto-electric dipole antenna with high-gain for base-station applications
The paper presents the results of a novel high-gain dual-band magneto-electric dipole (MED) antenna. The antenna comprises two pairs of horizontal metal plates of different heights that are excited by a Γ-shaped feedline structure. The antenna is entirely made of metal plates. Compared to traditional MED antennas the proposed design exhibits dual-band operation with higher radiation gain and whose frequency ratio can be modified by simply adjusting the heights of the two magneto-electric dipole segments. This feature is necessary for cellular base-station applications. The operation and characteristics of the antenna are validated by measurements. The measured results confirm the proposed antenna achieves fractional bandwidths of 13.31% (801.9-916.2 MHz) and 19.76% (1710.7-2085.7 MHz) for S11 ≤-10 dB. It has stable unidirectional radiation patterns and optimum radiation gains of 9.2 dBi and 7.8 dBi at the first and second operating bands, respectively
A Novel Technique for Rejecting the WLAN and WiMAX Bands in Ultrawideband Antenna
In this article a compact ultrawideband (UWB) circular patch antenna with a novel technique for rejecting the WLAN and WiMAX bands from the UWB frequency band is presented This method is based on applying a band notch structure instead of dual band notch system. The design of this UWB antenna is in the way that is able to reject the WiMAX band without using a filter structure and instead by introducing a semi C-shaped controllable notch band in the radiated patch which is capable of filtering the WLAN band The proposed antenna has compact size of 22mm x 30mm. The Measurement results are in relatively good agreement with the simulations. Copyright (C) 2009 Praise Worthy Prize S.r.l. - All rights reserve