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Published on: September 11, 2013 / Comments: None

In the near future, your cell phone may not need batteries

In today’s somewhat creepy too-good-to-be-true technology announcement is this technique called Ambient Backscatter.  In the demo, researchers create 2 devices that neither one takes batteries, yet they are able to communicate to each other.  The devices harness radio waves that are already in the air like TV signals.

By either choosing to absorb or reflect the existing signals, the other device notices either a 1 or a 0.  Thus data transfer wirelessly, without batteries!  These devices have to run on real low power to work, because it’s consuming some of the rf signals to harness as power.  The future for these devices is huge, imagine tons of little smart objects that can communicate, that don’t need batteries!  People are already making small things that sip battery power but they do eventually need batteries.  And typically those devices if they communicate wirelessly they are power hungry.

Amazing technology.  Read more on the writeup on phys.org for a more detailed explanation, or watch the video below.

 

Published on: July 25, 2013 / Comments: None

PCB antenna design, for dummies… well almost

I love how this article starts out, the age-old saying about RF and analog being taboo… so true!  Anyhoo, Colin takes you on a quick rundown of antenna basics, focusing on tuning PCB antennas.  This is one of those articles you see AFTER you need it, personally I totally could have used this months ago.  So we’ve all seen these PCB antennas, those little squiggly lines on your board that do the voodoo RF magic, but what do you do when you need to tune it ?  Well start by reading this article.

With the recent boom of cheap SDR’s flooding the market, more people are getting back into RF design.  Although I wouldn’t recommend using a fixed-tune antenna for a SDR, the theory by its self is worth the read.  Of course the biggest hurdle here for a DIY’er is going to be having access to a spectrum analyzer.