Microstrip Patch Array Design. Antenna arrays offer improved directivity compared to a single- radiator antenna. The directivity of an array is due to interference effects between the individual elements of the array, which means that the spatial distribution of the elements as well as phases and magnitudes at each element need to be tuned for optimal performance. Each of these can be considered separately by dividing the process of designing the array into separate stages. By creating the array in steps, the task of optimizing the design is made less challenging, and the most appropriate tools can be used at each stage. This article explains the design process for a planar microstrip patch array for WLAN frequencies using the circuit and full- wave 3. D solvers and optimization tools in CST STUDIO SUITE. The goal in this case is to design an array with high directivity, low cost and low sidelobes, exhibiting a good impedance matching in the frequency range 5. The same approach can also be used to design other types of array by using a different radiator or array layout. For this example, a simple square patch antenna was used (Figure 1), and was created directly in CST STUDIO SUITE. The patch is created on a double- layered substrate with an air gap, and is placed inside an ABS box. Section II represents the design of the suggested antenna. Design of a Corrugated Microstrip Patch Antenna with Modified Ground Plane 0491. COMPACT PATCH ANTENNA DESIGN FOR OUTDOOR RF ENERGY HARVESTING IN WIRELESS SENSOR NETWORKS. Effect of Slots in Ground Plane and Patch on Microstrip Antenna Performance. It is decided to design the rectangular patch. Slotted ground plane Patch Antenna. The ground plane required on one side of the antenna is. The Ground Plane Antenna. Like the dipole, the ground plane is resonant and typically. The Fundamentals of Patch Antenna Design. Basic Patch Antenna Design. Patch Antenna mounted on a ground plane with a. Antenna Design Considerations Ground plane Optimization Fundamental to the performance of a patch antenna. Microstrip Patch Array Design. This is due to the larger ground plane and the effect of the edge. Impedance matching is an essential part of antenna design. Two parameters need to be optimized: the length of the patch, in order to adjust the resonant frequency of the patch, and the depth of the air gap, in order to increase its bandwidth. This was done using the time domain solver, with a parameter sweep to vary these two parameters. In this case, the choice of box and patch type limits the possible layouts for the array, and so a 4 . However, any arbitrary array shape can be imported as a text file containing the location of each element and the magnitude and phase of the feeding current. This can be estimated by multiplying the farfield of the single patch by the array factor, which depends only on the spatial arrangement of the elements and the amplitude and phase of the feeding current of each element. A post- processing tool in CST STUDIO SUITE calculates the array factor and automatically produces a theoretical farfield for an equivalent array. Optimization can then be used to adjust the spacing between the elements to maximize the gain of the antenna, and to change the magnitude of the feeding current to different patches to reduce the side lobes. A more accurate approach is to simulate the entire array. The Array Wizard in CST STUDIO SUITE will construct an array model from a single element. As shown in Figure 2, the array factor and the full array model are generally in good agreement, even when the ABS casing is included. The largest difference is visible in the backwards radiation pattern. This is due to the larger ground plane and the effect of the edge elements. In our case, the patches, ABS box, substrate and aluminum plate are simulated in 3. D and the feeding network on a circuit level. Then the complete array will be automatically assembled into 3. D in order to investigate the coupling effects in the feeding network. With S- parameter symmetries, only 4 ports need to be excited to calculate the full 1. S- matrix. The blocks give an S- parameter representation of the transmission line, and are connected to another block containing the S- parameters from the full- wave simulation of the array without the feed network. The circuit simulation is very fast, but does not consider 3. D effects. Instead, this first optimization gives a good starting point for a more detailed 3. D analysis. The red circles on the model show the discrete ports. Feed network 3. D simulation. Figure 4: Full 3. D model of the array with the feeding network. When considered in 3. D, the characteristics of the feed network appear slightly different to those calculated using the circuit simulation. This is due to effects such as the coupling between the feed network and the patches, which only appears in a full- wave simulation. These couplings introduce a phase delay, which upsets the excitation of the patches and affect the uniformity of the magnitude distribution. Since the unwanted interaction between the patches and the feeding lines affects also the radiation pattern, the final optimization should consider both goals on impedance matching and radiation pattern. Because of rather high number of parameters and the complexity the global optimization strategy should be used. GPU computing with the time domain solver significantly reduces the optimization time of the whole array. The optimized array satisfied the - 1. B requirements, as shown in Figure 5. The most visible effect of the optimization was to change the length of the meanders so that meanders leading to inner patches are longer than those leading to outer patches. This equalizes the phase difference between the patches and improves the performance of the array. The optimized radiation pattern is depicted in Figure 6. The S- parameter results for the bare array (Figure 9) show a very good agreement between the simulated and measured S- parameters in terms of both magnitude and phase. In this case, the array is sensitive to variations in, for instance, the air gap between the substrate and ground plane, and these are the main source of uncertainity. The difference is slightly greater when the ABS front plate is included (Figure 1. Figure 1. 1 shows the gain of the array both as measured and as simulated. The co- polarization results agree very closely, as do the cross- polarization results in the H- plane. The asymmetry in the cross- polarization measurements is due to the metallic fixture, which was not present in the simulation. The measured E- plane cross- polarization level of between - 1. Bi and - 2. 0 d. Bi is however sufficient considering the much higher H- plane cross- polarization. Feb 2. 01. 4 4: 2. Sep 2. 01. 6 9: 5. Article ID 9. 15. All rights reserved. Without prior written permission of CST, no part of this publication may be. The design, developed by IETR- INSA / Thomson R& D France, shows good broadband matching (3- 1. GHz) and an omnidiectional radiation pattern up to 6 GHz. EM simulation is increasingly becoming an indispensable tool in the design flow, not only on the antenna level but also on the phone and environmental levels. This article compares simulated results with measurements for several steps in the phone design chain. The impact of composite materials on electromagnetic effects including installed antenna performance and lightning strikes will be explored. The webinar will also highlight recent advances in cable harness modeling and the effect of different shielding and grounding/bonding schemes for installation in aircraft. In this webinar we will focus on two topics: shielding effectiveness of enclosures and routing of differential lines. Even though the topics sound unrelated, they can be efficiently simulated with the same methods. Important figures such as the transmission, the mode volume and the quality factor are discussed. The presented information will help the reader to decide which type of photonic crystal cavities will be most suited for the application in view. A design example for a WDM channel filter is given in order to illustrate the design process for a photonic crystal cavity. Furthermore two experimental examples from recent research are shown to demonstrate the wide range of applications in which photonic crystal cavities could be used.
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