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.
4nec2 - A free NEC2/NEC4 implementation for Microsoft Windows. It is a tool for designing 2D and 3D antennas and modeling their near-field/far-field radiation patterns. Numerical Electromagnetics Code NEC2 unofficial home page - NEC2 documentation and code examples; MMANA-GAL basic - A free antenna modeling program based on MININEC. Opens .MAA ...
A horn antenna has a flaring metal horn attached to a waveguide. It is a simple antenna with moderate gain of 15 to 25 dBi, used for applications such as radar guns, radiometers, and as feed antennas for parabolic dishes. Slot Consists of a waveguide with one or more slots cut in it to emit the microwaves. Linear slot antennas emit narrow fan ...
English: Diagram of a J-pole antenna, a vertical end-fed half-wave omnidirectional transmitting antenna used in the shortwave frequency bands. It consists of a vertical element a half wavelength (/) long, fed in series with a quarter wavelength (/) transmission line stub, with the coaxial cable feedline (F) from the transmitter attached along the stub.
If it was infinitely thin the antenna would have an infinite input impedance, but the finite width gives typical, practical half wave whips an impedance of 800–1,500 ohms. These are usually fed through an impedance matching transformer or a quarter wave stub matching section (e.g. the J-pole antenna). An advantage is that because it acts as a ...
Moxon antenna for the 20-meter band.The antenna is the faint rectangle of wires held in tension by the bent X-shaped support frame. Moxon antenna for the 2-meter band. The Moxon antenna or Moxon rectangle is a simple and mechanically rugged two-element parasitic array, single-frequency antenna. [1]
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!
Patch antenna gain pattern. A directional antenna or beam antenna is an antenna which radiates or receives greater radio wave power in specific directions. Directional antennas can radiate radio waves in beams, when greater concentration of radiation in a certain direction is desired, or in receiving antennas receive radio waves from one specific direction only.