Packaging Effects of Multiple X-Band SiGe LNAs Embedded in an Organic LCP Substrate

Interconnects in radio frequency (RF) packages have a strong tendency to deteriorate RF performance, especially in high-frequency systems. In this paper, comparison is made between the wirebonded and embedded flip-chip packages. X-band silicon-germanium low-noise amplifiers are used to evaluate the performance of these interconnects. Measured results show that the embedded flip-chip packages have better RF performance than the wirebonded packages for X-band applications. At 9.5 GHz, the flip-chip interconnects contribute only 0.4 dB of insertion loss, while the wirebond interconnects contribute 2.2 dB of insertion loss. The flip-chip and wirebond interconnects are modeled and validated against measured results from 8 to 20 GHz. For the first time, multiple dies are put together in a single liquid crystal polymer package to compare the packaging effects, and to demonstrate the feasibility of embedding multiple dies within a single package for highly integrated solutions.