Tuning of narrowband near-field probes

An apparatus comprising:

• multiple near-field probes coupled in series, each near-field probe comprising loops or coils of electrically-conductive material and configured to generate a magnetic field;
• a power amplifier configured to drive the near-field probes;
• for each near-field probe, a shunt capacitance coupled in parallel across the loops or coils of the near-field probe, wherein the shunt capacitance and an inductance of the loops or coils of the near-field probe form part of a resistive-inductive-capacitive (RLC) network, and wherein the RLC network is configured to transform a smaller resistance of the near-field probe into a larger resistance;
• and
• multiple cables electrically coupling the power amplifier and the near-field probes and electrically coupling the near-field probes in series;
• wherein, for each near-field probe, the RLC network is configured to increase the resistance of the near-field probe in order to decrease electrical losses associated with the multiple cables.

A method comprising:

• amplifying an excitation signal using a power amplifier to generate a drive signal for one or more near-field probes, each near-field probe comprising loops or coils of electrically-conductive material;
• generating a magnetic field using each near-field probe based on the drive signal;
• and
• for each near-field probe, using a shunt capacitance coupled in parallel across the loops or coils of the near-field probe to form, along with an inductance of the loops or coils of the near-field probe, part of a resistive-inductive-capacitive (RLC) network, wherein the RLC network is configured to transform a smaller resistance of the near-field probe into a larger resistance;
• wherein multiple cables electrically couple the power amplifier and the one or more near-field probes;
• and
• wherein the RLC network for each near-field probe is configured to increase the resistance of the near-field probe in order to decrease electrical losses associated with the multiple cables.