The PACMAN antenna

When I came across the Pacman antenna or Circular edge-fed antenna with sectoral slot, it immediately caught my attention as it reminded me of my very early gaming years. Although the only similarity between the antenna and the game is its appearance, this antenna has some features worthy of note. One very useful feature is that (although it is fed with a microstrip line) it requires no matching section. By adjusting the sector angle and size (shown in the image below) the real impedance can be adjusted from 50 ? to 200 ?.

Circular edge-fed antenna with sectoral slot.

Circular edge-fed antenna with sectoral slot.

When comparing the Pacman antenna with the Circular inset fed patch it seems to have some definite advantages at lower (+- 50 ?) real impedances. Firstly, the Circular inset fed patch needs a very deep inset to achieve 50 ? and the impedance becomes very sensitive to minor physical changes or manufacturing tolerances. Secondly, when using low permittivity substrates the feed becomes very wide at 50 ?. This has a significant impact on the physical shape of the Circular inset fed patch, but relatively little impact on the edge fed Pacman antenna.

I?m wondering if one can?t manually adjust the impedance by changing the sector angle with a sliding device (almost like with a potentiometer, or variable resistor). Has anyone tried this?


Author: Robert Kellerman

2 Responses to “The PACMAN antenna”

  1. kabukicho2001 says:

    HI do you have the dimension for wifi 2.4 ghz case, r=15mm?

  2. Robert says:

    Hi, Antenna Magus can design the Pacman (Circular edge-fed patch with sectoral slot) at 2.4Ghz with r = 15mm. I will email you the pptx report generated by Antenna Magus. It contains all the physical design parameters, sketches and simulation graphs.

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