On Tuesday 20 December 2005 16:30, Eric Blossom wrote: > On Tue, Dec 20, 2005 at 03:30:56PM -0500, Marcus Leech wrote: > > Paul Shuch was working on a phased-array panel antenna for > > SETI work. I don't know how many elements, but it was > > steered using varactors. For some environments, this would > > be really nice--no need to build mechanicals to swing a dish > > around.
> For narrow-band arrays (bandwidth < 1% of center freq), we think we > can steer the array with DSP in the FPGA and/or host. This would > allow us to build 4 antenna arrays with a single USRP. Having been chief engineer for a directional AM broadcast station, phased arrays are right up my alley, even though this particular array was a transmit array (four inline 1/4-wave towers, spaced 1/4 wave apart, throwing the equivalent to a 20-element yagi pattern; front to back was 6KW:180mW). I've done 3D modeling of transmit phased arrays, and tuned them (the classic 'rocking the phasor' routine (yes, the phasing equipment is really called a phasor). See http://www.pari.edu/telescopes/RadioTelescopes/ETA and http://www.ece.vt.edu/swe/eta/ for details on a big phased array project being built at PARI. The short form: imagine repointing a dish after the observation has been taken. 12 terabytes per day required storage. Big time phased array; uses multiple Xilinx XC2VP30 boards (ML310) for the beam forming calculations. -- Lamar Owen Director of Information Technology Pisgah Astronomical Research Institute 1 PARI Drive Rosman, NC 28772 (828)862-5554 www.pari.edu _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
