I'm trying to design a patch antenna with an inset feed for impedance matching, but for some reason the EM wave refuses to propagate to the antenna. Any idea why?
Could it be a mistake in calculations? Would a slight mismatch create such discrepancy? This is really confusing. It worked perfectly before I added the inset (and moved the antenna in the -y direction to accommodate it).
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I've got it! It was indeed a dimension error (thanks volker_muehlhaus!). I extended the lower part of the antenna down but forgot to remove the top half. In effect, the antenna is 50% larger than it should be. I don't understand why the size difference effectively stopped the wave from propagating though.
I extended the lower part of the antenna down but forgot to remove the top half. In effect, the antenna is 50% larger than it should be. I don't understand why the size difference effectively stopped the wave from propagating though.
If the patch length was too large, then maybe the "top half" length was close to 1/2 wavelength, so that the "open circuit" at the edge is transformed into an open circuit at the feedpoint.
Thanks. One more thing I'm wondering; why is there no significant difference with the addition of inset feed? Now that the antenna impedance is matched to the microstrip line (from 234 ohm to 50 ohm), I would expect the return loss to be -40 dB or lower, but it's still only around -4 dB. Is there something I'm missing?