I am attempting to design an antenna for a 162.4 MHz omni receive only application and am confident it is going to be difficult if not impossible.
I have very tight specs on space(6" diameter by 3" deep cylinder) so the first antenna I came across was a quarter wave antenna.
162.4MHz length is 17.291 inches. Given my enclosure height this is not going to work.
The next antenna to look at is the rubber ducky. From wiki I find, "Rubber ducky antennas are typically 4% to 15% of a wavelength long; that is, 16% to 60% of the length of a standard quarter-wave whip.
So 17.291 inches in the quarter wave becomes 17.291*(.16)=2.76656 inches in the rubber ducky. Now I know having antenna this small will hurt the range terribly, but it meets the size requirement.
So I am attempting to understand how to design such an antenna. I have access to some equipment and will attempt to acquire the tools I need, but I lack the design flow to accomplish this.
Currently I have access to a spectrum analyzer w/ tracking and can get signal to noise ratio(SNR) and Received signal strength indicator (RSSI) values.
I have no issues with the impedance matching and am purely focused on how to design the physical antenna for my design.
Any suggestions or information would be greatly appreciated on how to go about designing a rubber ducky.
When I was looking to choice an antenna type: https://electronics.stackexchange.com/questions/131323/antenna-design-for-specific-directions
Can Rubber ducky be modeled: How much loss for 1 to 1.5 inch Coil (rubber ducky) Antenna at 70cm band?
- The enclosure is made from PLA plastic.
- Other then a ground place the diameter of the enclosure it will be in free space.
- There is a AC power cable running out of the top of the enclosure.
- The receiver circuit board is inside the volume.
- The orientation of the cylinder is 3" vertical & 6" horizontal
- The direction of the signals will be horizontal.
- I can ideally cope with a directional design, but this is not prefered.