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logic of phase at resonance order for "phased array" design from unit cell meta materials

yefj

Advanced Member level 4
Hello , I have built a unit cell wich intend to do beam steering using phased array theory.
So basicly i think of a unit cell as a "patch antenna".
my "patch" has two resonances i could tune.
Each resonance has its own phase as shown below.
the first resonance is at 0 degrees .the second resonance is 145 degrees.
Why at different resonance i get different phase?
What is the logic of the phase value at the resonances?
Which resonance i should use for phased array?
Thanks.

"For the impedance transfer function, the series resonance always occurs 1st from L1C1 with resonance at 0 deg. The 2nd resonance is parallel with C1 in series with C2 making it slightly smaller at the slightly higher f with 180 deg phase shift, thus requiring an inverter for an oscillator.

Gain margin for stability depends on the attenuation at resonance which is limited by Rs in series and the external Rs for parallel that must be less than the gain (f) of the amplifier."

In essence, an antenna can be considered as a type of an LC resonant circuit because it also involves inductance (L) and capacitance (C) components.
In an LC resonant circuit the phase change (due to the different behavior of the L and C components) and is crossing zero at resonant frequency. The same, the antenna change the phase and at antenna resonance the phase cross zero.
For your patch element, which will be part of an array, I would spend some time optimizing it, reducing any parasitic resonances at frequencies other than the desired one.

why we dont want other resonances and stick with the once with 0 degrees?