zeke 693 Posted October 31, 2011 Share Posted October 31, 2011 Anyone have any opinions on antenna placement? Is it a better idea to move it away from the rest of the components, or just have it the way it is now? Yes, yes and no. What is that red track on the right side of the board? From an RF point of view, it will short out the antenna. It would be best to have an off-board antenna. Maybe a wire monopole or a dipole on a chunk of coax. If you went with a dipole on coax then you could put a decent RF connector on the board and avoid routing pitfalls. I'll give you ideas on how to route your board if you like. What would you like to do? Quote Link to post Share on other sites
zeke 693 Posted October 31, 2011 Share Posted October 31, 2011 Edit:Thinking of revising antenna design using this DN: http://www.ti.com/lit/an/swra160b/swra160b.pdf That would be whizzy cool. But I doubt that this antenna could be made successfully at a place like SeeedStudio. The photolithography has to be freaking awesome to get those pcb track dimensions. If they're off then you'll be trimming the pcb with an Xacto knife and a spectrum analyzer. Not to mention that the ground plane has to be perfect for this to work. I would advise using an external antenna on coax. This will move the "obstacles to success" from antenna tuning over to ground plane designing. Designing a ground plane, in this case, is much easier to do. What do you think? Quote Link to post Share on other sites
HylianSavior 37 Posted October 31, 2011 Author Share Posted October 31, 2011 Anyone have any opinions on antenna placement? Is it a better idea to move it away from the rest of the components, or just have it the way it is now? Yes, yes and no. What is that red track on the right side of the board? From an RF point of view, it will short out the antenna. It would be best to have an off-board antenna. Maybe a wire monopole or a dipole on a chunk of coax. If you went with a dipole on coax then you could put a decent RF connector on the board and avoid routing pitfalls. I'll give you ideas on how to route your board if you like. What would you like to do? What do you mean by the "red track"? The one going up to one of the pins is a ground line, which should disappear once I put in a ground plane. As for antennas, I have no experience with them at all. Instead of the on-board antenna, do you think it would be good to put in an SMA connector instead? Quote Link to post Share on other sites
zeke 693 Posted November 1, 2011 Share Posted November 1, 2011 What do you mean by the "red track"? The one going up to one of the pins is a ground line, which should disappear once I put in a ground plane. Yeah, I figured that out later on. My apologies. As for antennas, I have no experience with them at all. Instead of the on-board antenna, do you think it would be good to put in an SMA connector instead? Unless you are a seasoned RF engineer then, yeah, that would be the way I would go. RF is black magic in the absence of hard fought testing and experience with it. It also requires access to freaking expensive RF test equipment. Also, using someone else's antenna makes the job easier to finish. You can assume that their antenna is fully functional and free of defects. All you have to do after that is design a 50 ohm transmission line between your module and your connector, select a desirable RF connector (SMA in this case) and make a really good ground plane on your circuit. To properly design an RF circuit, you have to take into consideration the following design topics: 1. Ground plane - has to be solid in order to avoid ground bounce and parasitic voltage induction. You can use the ground pour to protect vulnerable circuitry from an antenna that is close by. Fence out the noise with the ground plane. 2. Antenna PCB layout - make sure you design it to be a 50 ohm transmission line - RF reflections can cause transceiver damage and radiated harmonics 3. RF connector selection - choose something that isn't exotic or excessively tiny. You're not making 100Kunits yet. 4. Antenna selection - choose one that has the bandwidth and gain for your transceiver 5. Antenna placement - place it at least 1/2 wavelength from your active circuitry (C = f * lambda) Keeping these ideas in mind as you do your pcb layout will keep you away from the RF black magic and the need for expensive RF test equipment. I hope that's helpful. Quote Link to post Share on other sites
poofay 3 Posted November 3, 2011 Share Posted November 3, 2011 I'm not trying to thwart your plans, but I found a link to this webpage when looking up info on the g2553. I can't post links since I'm too new, but if you google the part number "430boost-cc110l" the first hit is the webpage. There isn't any info other than it listed as a preview device, but it looks like TI also thinks the launchpad needs a wireless booster pack. The CC110L is named their "value line" transceiver, so they seem like a good pair for each other. It could be months before they release it though! I've learned a ton while following this thread. Finish the board so you can say you beat TI to the punch! bluehash and HylianSavior 2 Quote Link to post Share on other sites
bluehash 1,581 Posted November 3, 2011 Share Posted November 3, 2011 Yup.. it is still in preview mode. Now we have two kinds of wireless boards, which is good. Thanks Poofay. HylianSavior : +1 for your work. HylianSavior 1 Quote Link to post Share on other sites
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