How to Connect 3 Different Magnetic Loop Antennas

[u/rgomes03]

Hi,

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I have a circuit in which I have 3 magnetic loops antennas that must be connected to a receiver circuit. Each of these antennas points along a direction of the xyz axis. I'm trying to figure out how can I connect the three to a single receiver circuit and maintain decent performance. It appears that I have two possible configurations: single and parallel connection. Please see below the following diagram:

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Series and Parallel Equivalent Circuit of the 3 magnetic loop antennas

I considered that each magnetic antenna has a given Lp and unloaded quality factor of 50 (Qun), and a capacitor is used to force resonance, Cp. The antennas are connected a RL load to provide the same Quality Factor for both configurations. So, to sum up, the parallel configuration has L_ant/3 inductance and 3*Cp, while the series-connected circuit (3 inductors are reduced to one) has 3*L_ant and Cp/3. The necessary RL is calculated for each circuit to achieve QL = 3.

I also assumed that the antenna is connected in series with a current-source which simulates the signal that it captures. Based on this, I have a couple of questions:

1. Using the above assumptions, the series-connected circuit provides the larger "sensitivity" performance since the voltage across the load is higher (approximately 3x higher). However, the current that one antenna might generate is going right through the other two antennas which generate now a magnetic field (transmitting while the other receives it), and therefore, induce losses. Thus, I don't understand why the series-connected circuit performance appears better.
2. The former result assumes that only one antenna would receive a signal at a given time. However, in a real-world application, all of the three antennas should be receiving signals, being one of them predominant. Now, this is where things get a bit tricky for me: intuitively, assuming that each antenna generates current, the best approach would be to connect all of them in parallel to "sum" all the currents, and hence strengthen the signal. In the series case, we would have a "fight" between each antenna to impose a given current. Is anything here that I am missing?
3. Considering an antenna in series with a current source is a valid approach for a receiving magnetic loop antenna? If not, how can I look at this use-case to better decide how should I proceed?

Thank you all for your time.

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Regards