Resonance in electronic means: reactance of zero. (maybe wrongly/correctly someone's calling the minimum VSWR, the resonance of antenna! and this cause confusion)
I've heard in Antenna Design for Mobile Devices book: "If your antenna does not have good resonator then matching circuit will not really help". Or look at this question on stackexchange-ham : "What is the best resonator in Yagi antennas?". I think they must say "radiator" instead of resonator! isn't that?
Because the resonance is not important in hypothetical radiator if we have no limitation in value of feeding/source impedance. For example: Radiator con have any reactive/resistive impedance, who care about it, if our source have impedance conjugate to radiator impedance, since there is not reflection.
But maybe the resistive impedance of radiator is physical characteristic of good radiator, but why? (and this is philosophy of calling the radiator, resonator!). Any idea about it?
Or maybe this (resonators are equal to good radiator) is conflicting concept, because if we use conjugate of pure reactive radiator, all of energy will transfer and we then have no reflection, then all energy have to radiate, isn't that? (If this is really conflicting then the quote from "Antenna Design for Mobile Devices" from Zhijun Zhang must be wrong!)
But if we deny the equality, more confusion will occur, since in this manner everything can radiate in our band of interest efficiently, (through matched source/line) and there is no lambda/2 limitation.
I need idea to stop being confused!
Question in glance: 1.Is there a different between definition of resonance in electronic and antenna? 2.Is the resonance is the characteristic of good antenna? why? 3.If yes, then what will happen to the signal, that transferred to antenna completely, through conjugate matching? Since it have to radiate but you told it is not a good radiator, what's different. 4.Is radiating efficiently mean having no reflection from antenna?