A Compact Self-Packaged Dielectric-based Microwave Balun

A compact self-packaged microwave balun with a unique dielectric-based structure is presented. The balun is fully encapsulated within a rectangular dielectric resonator block, whose metallized sidewalls naturally form the shielding cavity, eliminating the need for additional metal shielding cavity. This design leverages the high permittivity of the dielectric material to achieve a compact size while maintaining excellent performance. The balun employs a topology similar to the microstrip Marchand balun in a 3D background to obtain a wide operation band of 2.4-2.6 GHz band, demonstrating an insertion loss of less than 0.4 dB, an amplitude imbalance below 0.6 dB, and a phase imbalance within 180° ± 7° between its balanced output ports. The proposed self-packaged balun structure offers significant advantages in terms of integration simplicity, mechanical robustness, and miniaturization for modern microwave systems.