Whitepaper vs AppCad values monopole antenna

[Joe Wright]

I'm finding a discrepancy with numbers between the nwp_008 whitepaper (quarterwave printed monopole antenna for 2.45ghz) and AppCad values.

I've assumed you can measure that as a microstrip. Maybe that's wrong? Screenshot shows the values entered and results given.

Biggest difference is the guided wavelength which is reported as 68.92 instead of 92mm in the whitepaper. Also, I find a width of 3mm to give 50ohms.

Have I misunderstood something?

Thanks, Joe

[FormerMember]

A microstrip line is a waveguide, meaning that it is used to transport signals to the antenna. A microstrip line is a "signal line" with ground below it. A monopole antenna is "signal line" with no ground below. Therefore, I don't think it will work to use microstrip calculations to estimate the impedance of the antenna.

For antenna design, I would recommend you to follow the whitepaper nwp_008. The antennas on our development kits follow the recommendations from the whitepaper.

[Joe Wright]

Thanks, will follow your reference designs.