Antennas, plastic

The modern Russian MIA flaw detectors use pulse version of the method [1-3], which peirnits to produce very portable (0.7 - 1.5 kg) and simple instruments, convenient especially for in-service testing. The objects to be tested are multilayer structures of reinforced plastics, metals and other materials honeycomb panels, antenna fairings, propellers, helicopter rotors and so on. In mentioned instruments amplitude-frequency analog signal processing is used. 

Plastics will continue to be required in space applications from rockets to vehicles for landing on other planets. The space structures, reentry vehicles, and equipment such as antennas, sensors, and an astronaut s personal communication equipment that must operate outside the confines of a spaceship will encounter bizarre environments. Temperature extremes, thermal stresses, micrometeorites, and solar radiation are sample conditions that are being encountered successfully that include the use of plastics. 

The other approach to the reduction of the power loss to the dielectric material is by reducing the amount used. This is done by replacing part of the dielectric by air, an inert gas, or by vacuum. As examples there are three cable constructions in common use which employ these approaches to minimize dielectric loss. The first is the use of a foamed dielectric PS plastic that is commonly used in either twin lead transmission lines or in coaxial cables used for antenna lead-in wires in the UHF-TV antenna applications. The second system, which is illustrative of several sectional spacers, is used widely in communications cables of the coaxial type to minimize losses to the dielectric by reducing the amount of dielectric material in the cable. 

WAP. The WAP provides the wireless data communication service. It usually consists of a housing (which is constructed from plastic or metal depending on the environment it will be used in) containing a circuit board, flash memory that holds software, one of two external ports to connect to existing wired networks, a wireless radio transmitter/receiver, and one or more antenna connections. Typically, the WAP requires a one-time user configuration to allow the device to interact with the local area network (LAN). This configuration is usually done via a Web-driven software application which is accessed via a computer. 

EMI shielding for RF shielding and antenna dishes, a metal wire mat structure can be located in the empty mould and then impregnated by the flowing plastic. The metallizing... 

Composites are being employed in a number of automotive applications. These include racing car bodies as well as regular automobiles. Most automobiles have the lower exterior panels composed of rubbery, plastic blends, and/or composite materials. Corvettes have composite bodies that allow a lightweight vehicle with decent fuel economy and they do not rust. Other parts such as drive shafts and leaf springs in private cars and heavy trucks, antennas, and bumpers are being made from composite materials. 

The antenna for the other frequencies is typically moderately large, covering an area of several cm square. As a result, in silicon-based RFID tags, the antenna is processed separately on a piece of plastic or paper, and then the silicon chip is mounted onto the antenna using an attachment process. 

These electrical properties of GFSPS, along with heat resistance and flow-ability, allow GFSPS to be competitive with existing plastics in electrical applications such as various connectors, antennae, and other electrical devices. 

The antenna window for the millimeter-waves is a lens of plastic material, which can be heated by wires in order to increase the availability in the winter season. The whole sensor is mounted in air cooling slots of the vehicle front end or behind plastic bumper material by means of a model-specific bracket. 

Worker honey bees (Apis mellifera) were caught at the hive entrance and maintained with food and water ad libitum in small Plexiglas boxes until the beginning of the experiments. To evaluate the gustatory threshold and for learning and metabolism experiments, honey bees were immobilized individually in small plastic tubes with a drop of wax-collophane mixture laid between the dorsal part of the thorax and the tube. The head and the prothoracic legs were free to move, allowing the honey bee to clean its antennae from the repeated sucrose stimulations. Honey bees underwent a... 

Smart cards are among the fastest growing applications for electrically conductive adhesives. Smart cards are pocket-size plastic cards with thin embedded ICs that store, process and transfer data much in the manner of a mini-computer. Smart labels are also being developed where the substrate is paper instead of plastic. Flip-chip transponder chips and flexible antenna are incorporated producing, for example, low-cost radiofrequency identification (RFID) units. 

It should be noted that metallic pigments can also provide both electrical and thermal conductivity properties to the plastic material involved, hence they can let the system serve as an antenna and microwave absorber, for a number of specific applications. 

Recent advances in technology have even facilitated the deployment of printed antennas to achieve similar functionality like the traditional antennas. One possible way of printing antennas is to use silver conductive inks on plastic substrates or papers (Tecstra, n.d.). The main advantage of printed antennas is that they are cheap. 

This is a chemical (or material) that holds the antennae and the microchip together. It is something like a plastic film (Sweeney, 2005). 

At the recent International Solid-State Circuits Conference ISSCC held in San Francisco in February 2006, Cantatore and co-workers from Philips presented their plastics electronics RFID tag which can be printed directly on to a plastics substrate along with its antenna [5]. Currently a sificon chip based... 

Figure 1-7. Examples of plastics in the electrical and electronics field a) snap-in cable set of plugs and adapters, using Amoco s Ardel D-lOO polyarylate b) plastic parts in a sixty-ft.-diameter high-precision, high-frequency antenna c) schematic of a reinforced plastics/ composite radome that protects a 150-ft.-diameter radar antenna from its Maine environment view of reinforced plastics sandwich geodesic radome being assembled the completely assembled radome d) space-communication antenna. The horn of plenty uses an RP sandwich in its reflective panels (glass-fiber-TS polyester skins with a kraft paper-phenolic honeycomb core). It has a two-ply air-inflated Du Pont Hypalon/Dacron fabric elastomeric radome that will protect the antenna from the outside environment for many decades and uses other plastics. This site in Maine was the world s first ground-to-ground conununication satellite.

Radome (radiation dome) is used to cover a microwave electronic communication antenna. It protects the antenna from the environment such as the ground, underwater, and in the air vehicles. To eliminate any transmission interference, it would be desirable not to use a radome since transmission loss of up to 5% occurs with the protective radome cover material. The radome is made to be as possibly transparent to electromagnetic radiation and structurally strong. Different materials can be used such as plastics, wood, rubber-coated air-supported fabric, etc. To meet structural load requirements such as an aircraft radome to ground radomes subjected to wind loads, use is made of RPs that are molded to very tight thickness tolerances. Fig. 4.56 shows a schematic of a typical ground radome that protects an antenna from the... 

Figy re 4.56 Antenna (150ft) protected by a plastic radome... 

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