 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
| HomeDiscussion GroupsElectronicsBasicsRepairDesignCADComponentsEquipmentElectrical Engineering ElectronicsKB.com Contact UsLink To UsSearch & Site Map |
Electronics Forum / CAD / September 2003Antenna Pattern Shaping
I have a 1086-1094MHz monopole antenna mounted on a small ground plane. I would like to modify the ground plane so that it sees only signals in a cone from 45° above horizon and upwards. I'm clueless in this antenna world. How should I do this? Thanks! ...Jim Thompson | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | | http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food. > I have a 1086-1094MHz monopole antenna mounted on a small ground > plane. [quoted text clipped - 17 lines] > > I love to cook with wine. Sometimes I even put it in the food. See if I have this straight, you have a small linear antenna on a printed circute card you'd like to limit it so it receives only signals that fall from *above* the board such as might occure in radio signals from satalite communications? possibly a very small parabolic or hemispherical dish? or leaves of reflector material around the antenna at 45 degree angle to cut the strength of the side signals? Charles >> I have a 1086-1094MHz monopole antenna mounted on a small ground >> plane. [quoted text clipped - 9 lines] >> >> ...Jim Thompson [snip] >See if I have this straight, you have a small linear antenna on a printed >circute card you'd like to limit it so it receives only signals that fall [quoted text clipped - 4 lines] > >Charles It's actually a "rubber ducky" vertical-stub antenna attached to a BNC connector on a circular ground-plane. It receives signals from aircraft flying overhead. I just want to limit the reception to those in a 45° cone overhead, but kill the horizon response. ...Jim Thompson | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | | http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food. > It's actually a "rubber ducky" vertical-stub antenna attached to a BNC > connector on a circular ground-plane. > > It receives signals from aircraft flying overhead. I just want to > limit the reception to those in a 45° cone overhead, but kill the > horizon response. If you would like to experiment, drill a hole in the side of a coffee can that will allow you to insert the ducky. The hole should be about a quarter wavelength from the bottom of the can. Face the open end of the can straight up Have fun. >> It's actually a "rubber ducky" vertical-stub antenna attached to a BNC >> connector on a circular ground-plane. [quoted text clipped - 7 lines] >wavelength from the bottom of the can. Face the open end of the can >straight up Have fun. Good idea! ...Jim Thompson | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | | http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food. Corner reflector Jim.  SignatureGregg *It's probably useful, even if it can't be SPICE'd* http://geek.scorpiorising.ca > I have a 1086-1094MHz monopole antenna mounted on a small ground > plane. [quoted text clipped - 10 lines] > ...Jim Thompson > -- Talk to the guys at: news:rec.radio.amateur.antenna news:rec.radio.amateur.homebrew SignatureMichael A. Terrell Central Florida Antenna height determines the vertical radiation patern lobes. Your probably looking at 0.64 wavelength above the ground plane. But there is still a ground lobe present for a vertical. A horizontal dipole will give better results because of the ground reflections in the horizontal mode. And if set up as a corner refletor (as pointed out) it will work better. Cheers > I have a 1086-1094MHz monopole antenna mounted on a small ground > plane. [quoted text clipped - 17 lines] > > I love to cook with wine. Sometimes I even put it in the food. >I have a 1086-1094MHz monopole antenna mounted on a small ground >plane. [quoted text clipped - 3 lines] > >How should I do this? Lengthen the antenna in stages. At some point between 1/4 wave in length where it is now and 1/2 wave, you will get a null in the horizontal direction. You'll also get approximately 45 degree lobes both up and down, but the ground plane, if it's area is large enough, will reflect the downward 45 degree lobe upward. Jim Question? It's difficult enough receiving SSR transponder blibs on 1090MHZ with a vertical mounted on the roof, why limit it to 45deg Up and over? > I have a 1086-1094MHz monopole antenna mounted on a small ground > plane. [quoted text clipped - 18 lines] > > I love to cook with wine. Sometimes I even put it in the food. Drill hole in centre bottom of can that is about the width of your ground plane, stick rubber ducky through hole, grounding the can and adjust height of can sides to suit. It seems can height should be around a 45 degree angle from the antenna base, but practically this doesn't quite work. Can width will also make a difference, but it doesn't work out as some recognisable fraction of a wavelength (or didn't for me anyway). Al > I have a 1086-1094MHz monopole antenna mounted on a small ground > plane. [quoted text clipped - 9 lines] > > ...Jim Thompson SignaturePlease remove capitalised letters to reply My apologies for the inconvenience Blame it on the morons that spam the net |
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2009 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.