The effects of an electromagnetic crystal substrate on a microstrip patch antenna (original) (raw)
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Applied Physics A, 2011
Three novel shapes of mushroom-like electromagnetic bandgap (EBG) structures are presented in this paper. The three shapes are based on a rectangular metal strip with different combinations. The performances of the threeshape structures are studied by using both an incident plane wave method and transmission coefficient approach. The effect of height and via location is also studied to achieve multi or wide bandgap. These shapes are embedded in microstrip patch antenna substrates. The performance of the MPA is improved as increasing the antenna gain by 5 dBi, decreasing the surface current so improving the antenna radiation pattern as well as reducing the antenna size by more than 70% compared to the original size. The new shapes of EBG structures are integrated with MPA as a ground plane, where the conducting ground plane is replaced by a high impedance surface EBG layer. Parametric studies are conducted to maximize their impedance bandwidth and gain. It is found that the antenna bandwidth increased by approximately four times than the original band and its gain is similarly increased. Sample of these antennas are fabricated and tested to verify the designs.
Gain Enhancement of a Microstrip Patch Antenna Using a Cylindrical Electromagnetic Crystal Substrate
IEEE Transactions on Antennas and Propagation, 2000
A low profile, unidirectional, dual layer, and narrow bandwidth microstrip patch antenna is designed to resonate at 2.45 GHz. The proposed antenna is suitable for specific applications, such as security and military systems, which require a narrow bandwidth and a small antenna size. This work is mainly focused on increasing the gain as well as reducing the size of the unidirectional patch antenna. The proposed antenna is simulated and measured. According to the simulated and measured results, it is shown that the unidirectional antenna has a higher gain and a higher front to back ratio (F/B) than the bidirectional one. This is achieved by using a second flame retardant layer (FR-4), coated with an annealed copper of 0.035 mm at both sides, with an air gap of 0.04 0 as a reflector. A gain of 5.2 dB with directivity of 7.6 dBi, F/B of 9.5 dB, and −18 dB return losses ( 11 ) are achieved through the use of a dual substrate layer of FR-4 with a relative permittivity of 4.3 and a thickness of 1.6 mm. The proposed dual layer microstrip patch antenna has an impedance bandwidth of 2% and the designed antenna shows very low complexity during fabrication.
Microwave and Optical Technology Letters, 2003
In this paper, we investigate the effect of the offset patch and layer misalignments on the broadband characteristics of a twolayer, electromagnetically coupled, stacked patch antenna with airgap at the X-band. Linear and angular displacements of the parasitic patch on the dielectric layer are considered for the experimental study. The measured results show very robust impedance characteristics of the proposed antenna element against layer misalignment.
Microwave and Optical Technology Letters, 1991
The results of some experimental investigations on electromagnetically coupled microstrip antennas on two-layer substrates are reported in this article. The variation of input impedance of electromagnetically coupled square and circular microstrip patches, with the degree of overlapping between the patch and feedline, is studied. Also presented is the percentage shift of resonance frequency due to the change of this overlapping. A method of increasing the 1:2 V.S.W.R. bandwidth of the patch antenna is also indicated.
IMPROVING THE PERFORMANCE PARAMETERS OF MICROSTRIP PATCH ANTENNA BY USING EBG SUBSTRATE
The objective of this paper is to analyze the performance of electromagnetic band gap (EBG) antenna for base station applications through simulation. The proposed analysis is carried out using the high frequency structure simulator (HFSS). In our method, to overcome several intrinsic limitations of patch antennas such as constrict bandwidth, low gain, excitation of surface waves, the EBG concept is applied. The patch antenna and patch antenna surrounded by the EBG cells are characterized in terms of return loss and radiation pattern in an anechoic chamber.
Finite difference time domain analysis of a photonic crystal substrate patch antenna
Physica B: Condensed Matter, 2005
Planar microstrip patch antennas can achieve a wide range of radiation patterns. However, due to surface-wave losses, they have low bandwidth, low gain, and a potential decrease in radiation efficiency. In order to minimize the surface-wave effects, a photonic-band gap (PBG) substrate is proposed. The PBG structure significantly diminishes the surface-wave modes and thus improves the gain and far-field radiation pattern and efficiency. In this paper, using FDTD, an accurate full-wave analysis of surface-wave propagation in a rectangular microstrip patch antenna with and without PBG is presented. Finally, the antenna fabricated and result of measurement was compared with numerical simulation. r
Enhancing Patch Antenna Performance Using Micromachining and EBG Technologies
Proc. National Conference on Communication Technologies, Shivakashi, India, 2006
This paper presents the performance enhancements in a microstrip line fed patch antenna by the use of selective etching based on micromachining (MEMS technology), and triangular lattice 2-D electromagnetic band gap (EBG) substrate. This paper addresses the issues related to the fabrication of patch antenna on a high permittivity substrate such as Gallium Arsenide (GaAs), silicon with the increased surface wave losses. Three different patch antennas have been considered. The first is a conventional rectangular patch fabricated over a silicon substrate, in the second selective lateral etching has been carried in the substrate below the patch. The third structure that is being proposed in this paper uses an EBG substrate constructed by drilling cylindrical air holes in triangular lattice pattern in addition to the micro machined element. The use of both these methods have shown an increased bandwidth and reduction in surface wave losses.
2012
In this paper, we present a novel approach for improving the bandwidth of a microstrip patch antenna using Jerusalem crossshaped frequency selective surfaces (JC-FSSs) as an artificial magnetic ground plane. The invasive weed optimization (IWO) algorithm is employed to derive optimal dimensions of the patch antenna and JC-FSS element in order for the whole structure to work at 5.8 GHz with consideration of gain. For the most efficient design, the antenna and FSS ground plane are optimized together, rather than as separate components. Simulation results demonstrate that this optimum configuration (the microstrip patch antenna over the artificial magnetic ground plane) have a broad bandwidth of about 10.44%. This wide bandwidth is obtained while the thickness of the whole structure is limited to 0.1λ. Further more desirable radiation characteristics have been successfully realized for this structure. The radiation efficiency of the AMC antenna configuration was found to be greater than 85% over the entire bandwidth. In general by introducing this novel Jerusalem cross artificial magnetic conductor (JC-AMC) in lieu of the conventional perfect electric conductor (PEC) ground plane, the bandwidth enhancement of about 67% and a thinner and lighter weight design has been obtained. Sample antenna and EBG layer are also fabricated and tested, to verify the designs. It is shown that the simulation data in general agree with the measurement results for the patch antennas implemented with FSS ground plane.
RADIOELECTRONIC AND COMPUTER SYSTEMS
The dielectric material used as a substrate and the shapes of the patches play an important role in the performance of bandwidth, return loss, and gain of the microstrip patch antenna. This paper presents the relative study of different shapes of microstrip Patch antenna for different dielectric materials. The main application of these antennas is for satellite communication in Ku-Band. The height of the substrate plays an essential role in the enhancement of bandwidth and it is chosen 1.012mm and three substrate materials (RT Duroid (5880), Teflon, and FR4) with different dielectric constants were chosen for the performance comparison. Aperture coupling, which is again one of the promising techniques for bandwidth enhancement, is used as a feeding technique for the designs. Coupling must be taken care of while using aperture coupling, which is done by precisely optimizing the feed line dimensions, feed position, slot dimensions, and patch dimensions. The antenna performance is stud...
Microstrip Antenna Phased Array With Electromagnetic Bandgap Substrate
IEEE Transactions on Antennas and Propagation, 2004
Uniplanar compact electromagnetic bandgap (UC-EBG) substrate has been proven to be an effective measure to reduce surface wave excitation in printed antenna geometries. This paper investigates the performance of a microstrip antenna phased array embedded in an UC-EBG substrate. The results show a reduction in mutual coupling between elements and provide a possible solution to the "blind spots" problem in phased array applications with printed elements. A novel and efficient UC-EBG array configuration is proposed. A probe fed patch antenna phased array of 7 5 elements on a high dielectric constant substrate was designed, built and tested. Simulation and measurement results show improvement in the active return loss and active pattern of the array center element. The tradeoffs used to obtain optimum performance are discussed. Index Terms-Electromagnetic bandgap (EBG), microstrip antenna phased array, mutual coupling, uniplanar compact electromagnetic bandgap (UC-EBG) geometry.