Phased Array Design Issues
1) Radiating element design
- Just one wire cut for 20m?
- Multiple wires for 20,15,10?
- Traps for 15,10 (17?, 12?)
2) Matching network in junction box.
- What bands need networks? (on lower bands, 40/75, forward gain is real low,
but nulls might be useful (esp on 40))
- Structure of network. 40m needs series L and impedance transformation from
ca. 7 ohms up to ca. 50-70
- What bandwidth does matching network need, considering some X can be taken
out at other end of feed
3) Control methodology for junction box
- brute force multiple wires, relay drivers in box or on ground?
- some signalling protocol and relay drivers in box?
4) Switching topology for steering
- SPDTs or reversing switch or??
- in box (2 coax to ground)
- paired coax to ground (4 coax to ground)
- before or after phasing networks
6) Current transducers?
- do we even need them (other than academic interest), or can we steer array
- what sort of amplitude and phase detector
- amplitude and phase detectors on ground
- amp and phase detector in box, send phase reference up to box
- send DC signals down, or digitize and send down by remote control
7) Control of matching networks
8) design generalization for portable ops (single band?)
antenna/phased/issues.htm - 19 Dec 2002 - Jim Lux
phased array home antenna home
Jim Lux home
email comments email@example.com