Design of omnidirectional Rydberg atomic sensors loaded with electric field enhancement structure using characteristic mode analysis

• Characteristic mode analysis enables efficient and accurate prediction of omnidirectional reception patterns for Rydberg atomic sensors without full-wave simulations. • The analytical modal coefficient representation dramatically reduces computational complexity for analyzing electric field enhancement structures. • Three prototypes validate the method; the final design achieves a 25 dB electric field gain and 2.4 dB out-of-roundness at 1.96 GHz. • The proposed approach provides actionable design guidance for omnidirectional Rydberg sensors, advancing quantum precision measurement technology.