With the rapid development of wireless communication technology, high-performance miniaturized RF circuits are becoming more complicated, and more functions and signals are being packed into a small, tight space, resulting in a significant level of electromagnetic (EM) interference and signal crosstalk. In modern wireless communication systems, a higher signal-to-noise ratio is desirable and can be attained using differential signals and circuits. Using the differential technique, commonmode (CM) interference is rejected, enhancing signal transparency. Thus, lots of attention has been drawn to differential/balanced circuits, owing to their advantages over traditional single-ended circuits, such as immunity to interference, high reliability, considerable output power, harmonic suppression, and so on . Corresponding to this trend, differential topologies have been used to design basic and key devices for RF front-end systems, such as filters , , power dividers , antennas , , and active components .