Unfortunately, SMART antennas are not easily available due to lack of consumer information and higher cost. The following are a couple models you may want to look into online or at your local electronic stores:

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Sylvania SMART Digital Antenna DTA500
While it is generally designed for outside use, you can install it indoors with your SMART antenna compatible DTV converter box. The built in amplifier can maximize any weak TV signals for all of your region’s VHF and UHF channels. Average cost is about a hundred dollars.

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RCA ANT2000
The RCA ANT2000 is designed especially for DTV converter boxes. It is optimized for HDTV reception for both VHF and UHF channels. The design allows you to lay it flat or hang it on a wall. Price is around sixty to eighty dollars.