The requirements for electronic packaging are continually increasing, since the trend is towards more personal and highly integrated products. The demands for electronic packaging are lower cost, lighter weight, lower power consumption, and higher integration rate. These requirements can be addressed with System-in-Package (SiP) technologies, which is a powerful concept for system integration. SiP, together with embedded passives, provides an attractive option to solve future packaging challenges. It has a huge potential especially with small portable electronics, such as, wireless headsets and portable terminals. This paper describes the design of embedded stripline baluns for 2.4 GHz low-range radio applications. We will discuss the design, implementation, and layout of three-dimensional baluns. The effect of a balun's layout was studied with a three-dimensional electromagnetic simulator, which is based on the finite-integration technique. Good impedance match and excellent amplitude and phase balances between output ports were achieved. In addition, several prototypes were also manufactured and measured. The correlation between the simulation and experimental results was excellent. The error between modeled and measured center frequencies was less than three percent.