Search results
Results from the WOW.Com Content Network
The J-pole antenna is an end-fed omnidirectional half-wave antenna that is matched to the feedline by a shorted quarter-wave parallel transmission line stub. [5] [1] [6] For a transmitting antenna to operate efficiently, absorbing all the power provided by its feedline, the antenna must be impedance matched to the line; it must have a resistance equal to the feedline's characteristic impedance.
With no matching unit, Varney specified 75 Ω cable be used at the junction of the ladder line and coax (not 50 Ω); the higher 75 Ω impedance makes a closer match the end of the ladder line. An earth-grounded 4:1 voltage balun may be used to connect the coax to the ladder line, and 1:1 current balun should be used between the coax and the ...
The most widely used types of feed line are coaxial cable, twin-lead, ladder line, and at microwave frequencies, waveguide. Particularly with a transmitting antenna, the feed line is a critical component that must be adjusted to work correctly with the antenna and transmitter. Each type of transmission line has a specific characteristic impedance.
That is, the resulting spin operators for higher spin systems in three spatial dimensions, for arbitrarily large j, can be calculated using this spin operator and ladder operators. They can be found in Rotation group SO(3) § A note on Lie algebras. The analog formula to the above generalization of Euler's formula for Pauli matrices, the group ...
Ladder line is an older, simpler form of parallel-wire line, often called open wire line. The configuration looks like a rope ladder , hence the name. It can either be purchased already made by a cable company, or home-made ; the construction is easy, though tedious, and originally all radio amateurs made their own open wire line.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
A via fence consists of a row of via holes, that is, holes that pass through the substrate and are metallised on the inside to connect to pads on the top and bottom of the substrate. In a stripline format both the top and bottom of the dielectric sheet are covered with a metal ground plane so any via holes are automatically grounded at both ends.
Just Words. If you love Scrabble, you'll love the wonderful word game fun of Just Words. Play Just Words free online! By Masque Publishing