Author Topic: Wire vs. Helical vs. Trace Antenna - Any Meaningful Differences?  (Read 301 times)

handyguy

  • Newbie
  • *
  • Posts: 21
For a current project I need a portable module (i.e., a Mote inside a portable case) and I'm trying to figure out the right antenna option to use. I'm worried that an antenna sticking out of the case will break off with moderate use of the device, so that means that the antenna assembly will need to fit in the enclosure. My options seem to be:
  • Standard Moteino with the wire antenna wrapped in/around the inside of the case
  • Standard Moteino with a helical antenna
  • Moteino with the trace antenna option

This is my first RF project so I'm worried about getting it "right" (or, at least, not crippling the device with the wrong selection.) All other things being equal (location between nodes, power, etc.), what are the big difference between these antenna options that I should be aware of as I design the project & enclosures?

Thanks in advance.

Kilo95

  • Sr. Member
  • ****
  • Posts: 313
  • Country: us
Re: Wire vs. Helical vs. Trace Antenna - Any Meaningful Differences?
« Reply #1 on: January 12, 2019, 03:46:19 PM »
Option 1 could alter the SWR and therefore power output. Itd also alter the radiation pattern and probably lower the range.

Kilo95

  • Sr. Member
  • ****
  • Posts: 313
  • Country: us
Re: Wire vs. Helical vs. Trace Antenna - Any Meaningful Differences?
« Reply #2 on: January 12, 2019, 03:48:39 PM »
Sorry. Hit the wrong button and Im on my phone.

Option 2 or 3 would probably be the best option. Downside of these choices over the quarter or  halfwave dipole is most likely less range

TomWS

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 1873
Re: Wire vs. Helical vs. Trace Antenna - Any Meaningful Differences?
« Reply #3 on: January 12, 2019, 05:20:29 PM »
Option 4 would be a ceramic chip antenna.  They're small and decent gain.  This, of course, assumes you're doing your own PCB.

I've had good success with Yageo (see Digikey).

handyguy

  • Newbie
  • *
  • Posts: 21
Re: Wire vs. Helical vs. Trace Antenna - Any Meaningful Differences?
« Reply #4 on: January 13, 2019, 10:05:05 PM »
@TomWS, I'm not looking to design my own PCB. I'm having enough challenges working with stock parts.  ;)

@Kilo95, realizing there are probably a dozen variables (at least) that affect performance and wave propagation, would the trace antenna or the helical be a better bet? The units would be probably 50-100 feet apart between floors of a house.

Or is it a toss-up? I have 2 units, maybe I'll use one type in each and see how it works out?

Felix

  • Administrator
  • Hero Member
  • *****
  • Posts: 5823
  • Country: us
    • LowPowerLab
Re: Wire vs. Helical vs. Trace Antenna - Any Meaningful Differences?
« Reply #5 on: January 14, 2019, 09:20:59 AM »
handyguy,

It's hard to guesstimate how each antenna will perform since there are so many variables. I suggest just trying, in the order it makes sense (cost? compactness? ease of installation and use?).

Generally speaking, a bigger antenna will work better (ie bigger "speaker" can propagate "music" better than a tiny compact speaker, same everything else). In most cases the simple monopole will work absolutely great, if you can deal with it and not crumple it too badly in your project. Even in SwitchMotes, where they have to be wrapped around inside the case, they work across a large multi level typical american home, and in industrial settings. The helicals I offer in the store are also great compact performers.

handyguy

  • Newbie
  • *
  • Posts: 21
Re: Wire vs. Helical vs. Trace Antenna - Any Meaningful Differences?
« Reply #6 on: January 14, 2019, 09:34:32 AM »
Thanks, Felix. I'm still trying to design the final layout, it's good to know I have options.