  Exceptional points (EP) in non-Hermitian systems have been widely
investigated due to their enhanced sensitivity in comparison to standard
systems. In this letter, we report the observation of higher-order
pseudo-Hermitian degeneracies in an electronic platform comprised of three
inductively coupled gain-loss-loss LC resonators. Theoretical analysis
demonstrates that the proposed system can realize third-order EP with
asymmetric coupling between adjacent inductors and an arbitrary scaling factor
between two loss resonators. When capacitive perturbation is introduced on the
middle resonator, the perturbed eigenfrequencies follow a cube-root dependence
on the perturbation parameter; in this case, the sensitivity is significantly
greater than conventional wireless readout methods. Our work enriches the
explorations of higher-order EP on electronic platforms and provides a new
degree of design freedom for the non-Hermitian-EP-enhanced wireless sensing
system.
