Non-Radiative Electromagnetic Near-Field Coupler: A Topological Electromagnetic Structure for Local Gravitomagnetic Effect Detection

This paper proposes an electromagnetic topological structure based on opposing conical coils, which generates a rotating near-field with localized energy and suppressed far-field radiation. By optimizing the cone angle (20°), number of turns (10), pulse current (50 A, duty cycle < 1%) and second-order resonance mode, the structure produces a localized magnetic field of approximately 53 mT at the waist. Using a plane-wave impedance relation as an exploratory upper-bound approximation, an equivalent electric field of approximately 1.6×10⁷ V/m and a localized energy density of approximately 1.1×10³ J/m³ are estimated.Based on a simplified weak-field gravitoelectromagnetic (GEM) analogy, heuristic order-of-magnitude estimation yields a local gravitomagnetic signal on the order of 10⁻⁷ s⁻¹, nominally within the detection range of existing ring laser gyroscopes and atom interferometers. It must be emphasized that this optimistic signal estimate relies on multiple non-rigorous simplifications. Under fully linearized general relativity, additional suppression would render the signal far below current sensor limits.The core contribution of this work is to provide a desktop experimental platform to test whether localized rotating electromagnetic energy flow can induce gravitomagnetic spacetime dragging, without requiring superconducting materials or mechanical rotation.