Optimization of Radiation Efficiency of Multi-modal Microwave Antenna Based on Diamond NV Center Dynamics Decoupling Cooperative Superheterodyne Detection and Sub-microtesla Magnetic Sensitivity Enhancement Mechanism

This study addresses challenges in suppressing high-frequency noise and achieving a balance between gain and phase consistency in weak magnetic field detection. We propose a multi-band, omnidirectional antenna array design that integrates spiral, patch, and phased array antennas for enhanced microwave radiation efficiency and magnetic field sensitivity. By applying dynamic phase control and metasurface structures, we improve weak magnetic field detection in specific directions. The use of Kalman filtering and adaptive compensation technology suppresses noise and corrects resonance frequency offsets, leading to significant improvements in signal stability and sensitivity. Experimental results demonstrate an extended signal coverage of over 17m, a signal-to-noise ratio (SNR) of 25.69 dB, and magnetic field detection sensitivity reaching -97.58 dB. This approach offers a significant enhancement in magnetic field detection for quantum sensing applications.