A tapered double balun that provides for a four terminal balanced feed line

Inventors at the Georgia Institute of Technology have invented a tapered double balun that provides for a four terminal balanced feed line. The feed line is constructed in such a way that it is particularly useful for rotationally-symmetrical frequency independent antenna implementations. The invention allows for extending the taper to reduce the low-frequency end of the response to an arbitrarily small value. This design can be used for spiral, sinuous or other four-arm antennas. The balun design is comprised of two outer ground planes and a center conductor that is dielectrically separated from the ground planes. The ground planes are constructed in manner to taper off at one end from a wide dimension to a narrow dimension.

Solution Advantages
  • Inexpensive alternate antenna design to conventional stripline antennas
  • Improves gain and is compact in size/shape
  • Enables improved bandwidth response by changing the length of the taper
  • Easily designed and manufactured using PCB (print circuit board) technology
  • Overcomes current technology limitations for producing circular polarized omni-directional antenna patterns
Potential Commercial Applications
  • Wireless devices
  • Devices or systems that require broadband transmission capability
  • WiFi devices, routers, cellphones and portable devices capable of handling streaming video
  • Network equipment
  • MIMO (multiple input multiple output) type antenna systems
Background and More Information

Antennas using balun design are intended for applications that require broad bandwidth data transmissions. An enhancement to the conventional balun design is the tapered balun, which enhances the broadband width data transmission from the devices. The key benefit of using a tapered balun is to allow a balanced transmission to become unbalanced without the use of striplines.