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Title: 433 Mhz High Gain Helical Antenna Designing Post by: localcrack on June 17, 2017, 02:12:49 14:12 Recently I am searching reference design for 433 Mhz helical antenna.
I got lot's of link that will confuse me because all design uses different configuration such as number of turns, lengths, diameters etc. If anybody has antenna design knowledge then please explain a bit how to design it. I have checked following links https://github.com/OpenHR20/OpenHR20/wiki/2.1)--433-MHz-and-868-MHz--Antenna-Design-Examples (https://github.com/OpenHR20/OpenHR20/wiki/2.1)--433-MHz-and-868-MHz--Antenna-Design-Examples) http://www.instructables.com/id/433-MHz-Coil-loaded-antenna/ (http://www.instructables.com/id/433-MHz-Coil-loaded-antenna/) https://www.elektor.nl/Uploads/Forum/Posts/How-to-make-a-Air-Cooled-433MHz-antenna.pdf (https://www.elektor.nl/Uploads/Forum/Posts/How-to-make-a-Air-Cooled-433MHz-antenna.pdf) Some ready made available antenna has also different configuration http://www.ebay.com/itm/10pcs-433MHz-10W-50-Copper-Spring-Antenna-433MHz-Helical-antenna-32mm-Length-/321398045993?autorefresh=true (http://www.ebay.com/itm/10pcs-433MHz-10W-50-Copper-Spring-Antenna-433MHz-Helical-antenna-32mm-Length-/321398045993?autorefresh=true) https://www.aliexpress.com/item/433mhz-315-mhz-Antenna-For-433mhz-315mhz-RF-Receiver-and-transmitter-Module-For-Wireless-Remote-Controls/32808390227.html?spm=2114.01010208.3.82.krG4cl&ws_ab_test=searchweb0_0,searchweb201602_5_10152_10065_10151_10068_5010014_10136_10137_10060_10138_10155_10062_437_10154_10056_10055_10054_10059_303_100031_10099_10103_10102_10096_10052_10053_10142_10107_10050_10051_5030014_10084_10083_10080_10082_10081_10110_519_10175_10111_10112_10113_10114_10182_10185_10078_10079_10073_10123_10189_142,searchweb201603_2,ppcSwitch_5&btsid=34926833-9c52-4131-9252-19626f45a82c&algo_expid=75842817-aa35-4915-be13-4377d86b22f7-10&algo_pvid=75842817-aa35-4915-be13-4377d86b22f7 (https://www.aliexpress.com/item/433mhz-315-mhz-Antenna-For-433mhz-315mhz-RF-Receiver-and-transmitter-Module-For-Wireless-Remote-Controls/32808390227.html?spm=2114.01010208.3.82.krG4cl&ws_ab_test=searchweb0_0,searchweb201602_5_10152_10065_10151_10068_5010014_10136_10137_10060_10138_10155_10062_437_10154_10056_10055_10054_10059_303_100031_10099_10103_10102_10096_10052_10053_10142_10107_10050_10051_5030014_10084_10083_10080_10082_10081_10110_519_10175_10111_10112_10113_10114_10182_10185_10078_10079_10073_10123_10189_142,searchweb201603_2,ppcSwitch_5&btsid=34926833-9c52-4131-9252-19626f45a82c&algo_expid=75842817-aa35-4915-be13-4377d86b22f7-10&algo_pvid=75842817-aa35-4915-be13-4377d86b22f7) One more question is that Does antenna design really improves transmission or receiving range ? Title: Re: 433 Mhz High Gain Helical Antenna Designing Post by: 2N5109 on June 17, 2017, 10:53:43 22:53 Are you looking for a tiny "rubber ducky" for 433 MHz to put on a PC board? This type antenna has poor efficiency and gain but they are useful if both ends of a link are nearby, like a car and its paired keyless entry keyfob. It is also known as a radial mode helical antenna, as opposed to the axial mode helical antenna which is much larger, is more efficient and has much better efficiency. Your best bet if youre looking for the small keyless entry antenna would be to buy one from ebay or Amazon.
There is a simple nomogram for this design at http://www.qsl.net/aa1ll/helical2.jpg . A higher gain antenna will give better pre-detection signal to noise ratio when the received noise is internally limited, i.e., when external noise (atmospheric, galactic, man-made, etc.) is much less than noise generated by stages internal to the radio (LNA, mixer, filter, etc.). Higher SNR will normally result in longer range for a data link. So, yes, when the received noise is due mostly to the internal stages of the radio, a higher gain antenna will increase range. For example, if there is lots of man-made noise around, this will not be true since the antenna is receiving both signal and noise. --2N5109 Title: Re: 433 Mhz High Gain Helical Antenna Designing Post by: bigtoy on June 20, 2017, 05:11:41 05:11 Check the ARRL manuals. There are some posted on this site. Some years ago I built a helical antenna for use receiving a weather satellite signal; the design (and the calculations for it) came straight out of the ARRL manuals.
Title: Re: 433 Mhz High Gain Helical Antenna Designing Post by: localcrack on June 20, 2017, 07:28:27 07:28 is any easy to go tools available for helical antenna design ?
Title: Re: 433 Mhz High Gain Helical Antenna Designing Post by: pablo2048 on June 20, 2017, 08:10:51 08:10 Antenna design is some kind of magic combined with previous experience, so IMHO there is no "easy to go" tool...
Title: Re: 433 Mhz High Gain Helical Antenna Designing Post by: perithess on June 25, 2017, 09:27:24 09:27 As mentioned above helical antenna has poor transmission and reception efficiency. If space is your matter for this application then you should try to find a calculator and optimize an antenna for your application. I used a calculator for this process but I can't remember it now. My advice is to follow the parameters of the calculator otherwise you will end with a bad antenna.
But if you have plenty of space you can look for more efficient antennas like a tuned monopole or dipole. Regards Periklis PS: Antenna design is magic but if you have the right tools is mostly visual magic :) Title: Re: 433 Mhz High Gain Helical Antenna Designing Post by: witsanukai on July 12, 2017, 08:07:39 08:07 basic way
433MHz design you can try by easy way using some copper wire and calculation whip leght by. waveleght(meter) = (Velocity/Frequency), you may need 1/4lamda (1/4 waveleght) there for. (300/433MHz)=0.69meter, So you need 0.69/4 = 0.17meter=17cm Then you need to cut wire 17cm to made whip antenna, anyway if you need shorter you just try to winding like coil spring to reduce lenght should be ok, hope this help. :) |