barcode in vb.net 2010 Quarter-Wave Verticals in Software

Generating USS Code 39 in Software Quarter-Wave Verticals

Quarter-Wave Verticals
Code-39 Scanner In None
Using Barcode Control SDK for Software Control to generate, create, read, scan barcode image in Software applications.
USS Code 39 Generator In None
Using Barcode drawer for Software Control to generate, create Code 3 of 9 image in Software applications.
A quarter wavelength is related to frequency by the equation: Lft = 246v/fo
Scanning Code 39 Extended In None
Using Barcode scanner for Software Control to read, scan read, scan image in Software applications.
Code 39 Extended Generation In C#.NET
Using Barcode creator for .NET Control to generate, create ANSI/AIM Code 39 image in VS .NET applications.
Quarter-Wave Verticals 475
Code-39 Drawer In Visual Studio .NET
Using Barcode generation for ASP.NET Control to generate, create Code 39 Extended image in ASP.NET applications.
Print ANSI/AIM Code 39 In .NET
Using Barcode printer for .NET framework Control to generate, create Code 3/9 image in VS .NET applications.
where Lft represents /4 in feet, fo represents the frequency in megahertz, and v represents the velocity factor. If the length is expressed in meters as Lm, then the formula is: Lm = 75v/fo For a typical wire conductor, v = 0.95 (95 percent); for metal tubing, v can range down to approximately 0.90 (90 percent). A /4 antenna must be operated against a low-loss RF ground. The feed-point impedance over perfectly conducting ground is approximately 37 . This represents radiation resistance in the absence of reactance, and provides a reasonable impedance match to most coaxial transmission lines.
USS Code 39 Maker In Visual Basic .NET
Using Barcode encoder for VS .NET Control to generate, create Code 3/9 image in VS .NET applications.
Barcode Generator In None
Using Barcode creator for Software Control to generate, create bar code image in Software applications.
Ground-Mounted Vertical The simplest vertical antenna is a /4 radiator mounted at ground level. The radiator is fed with a coaxial cable. The center conductor is connected to the base of the radiator, and the shield is connected to a ground system. Unless an extensive ground radial system is installed, a ground-mounted vertical is likely to be inefficient unless the surface happens to be an excellent conductor (saltwater or a salt marsh, for example). Another problem is the fact that vertically polarized antennas receive more human-made noise than horizontal antennas. In addition, the EM fields from ground-mounted transmitting antennas are more likely to cause interference to nearby electronic devices than are the EM fields from antennas installed at a height. Ground Plane A ground-plane antenna is a vertical radiator, usually measuring /4, operated against a system of /4 conductors called radials. The feed point, where the feed line joins the antenna radiator and the hub of the radial system, is elevated. When the feed point is at least /4 above the ground, only three or four radials are necessary to obtain a low-loss RF ground system. The radials extend outward from the base of the antenna at an angle between 0 and 45 with respect to the horizon. Figure 27-3A illustrates a typical ground-plane antenna with four horizontal radials. A ground-plane antenna should be fed with coaxial cable. The feed-point impedance of a ground-plane antenna having a /2 radiator is about 37 if the radials are horizontal; the impedance increases as the radials droop, reaching about 50 at a droop angle of 45 .
Code 3/9 Creation In None
Using Barcode creator for Software Control to generate, create Code 39 image in Software applications.
Create ECC200 In None
Using Barcode encoder for Software Control to generate, create Data Matrix ECC200 image in Software applications.
27-3 Basic quarter-wave
Generating Code 128 Code Set B In None
Using Barcode printer for Software Control to generate, create Code 128B image in Software applications.
UPC-A Generator In None
Using Barcode maker for Software Control to generate, create UPCA image in Software applications.
verticals. At A, ground-plane antenna. At B, coaxial antenna.
Make ANSI/AIM ITF 25 In None
Using Barcode printer for Software Control to generate, create 2/5 Interleaved image in Software applications.
Painting Bar Code In Java
Using Barcode generation for Java Control to generate, create barcode image in Java applications.
476 Antennas
Creating GTIN - 13 In Java
Using Barcode creation for Java Control to generate, create European Article Number 13 image in Java applications.
EAN 13 Reader In .NET
Using Barcode reader for VS .NET Control to read, scan read, scan image in .NET applications.
Coaxial Antenna The radials in a ground-plane antenna can extend straight downward, and then can be merged to form a /2 cylinder or sleeve that is concentric with the feed line. In this case, the feed-point impedance is approximately 73 . This is known as a coaxial antenna (Fig. 27-3B).
Draw UPCA In Visual Studio .NET
Using Barcode encoder for Reporting Service Control to generate, create UPC Code image in Reporting Service applications.
Barcode Recognizer In Java
Using Barcode Control SDK for Eclipse BIRT Control to generate, create, read, scan barcode image in Eclipse BIRT applications.
Loops
EAN / UCC - 14 Drawer In None
Using Barcode creator for Font Control to generate, create EAN 128 image in Font applications.
Code 3/9 Generation In Java
Using Barcode printer for BIRT reports Control to generate, create ANSI/AIM Code 39 image in BIRT applications.
Any receiving or transmitting antenna, consisting of one or more turns of wire forming a dc short circuit, comprises a loop antenna.
Small Loop A small loop antenna has a circumference of less than 0.1 (for each turn) and is suitable for receiving, but generally not for transmitting. It is the least responsive to signals coming from along its axis, and most responsive in the plane perpendicular to its axis. A capacitor can be connected in series or parallel with the loop to provide a resonant response. An example of such an arrangement is shown in Fig. 27-4. Small loops are useful for radio direction finding (RDF), and also for reducing interference caused by human-made noise or strong local signals. The null along the axis is sharp and deep, and can be pointed in the direction of an offending signal or noise source. Loopstick For receiving applications at frequencies up to approximately 20 MHz, a loopstick antenna is sometimes used. This antenna, a variant of the small loop, consists of a coil wound on a solenoidal (rodshaped), powdered-iron core. A series or parallel capacitor, in conjunction with the coil, forms a tuned circuit. A loopstick displays directional characteristics similar to those of the small loop antenna shown in Fig. 27-4. The sensitivity is maximum off the sides of the coil, and a sharp null occurs off the ends.
Copyright © OnBarcode.com . All rights reserved.