In recent years, remotely powered devices have become popular. Since WPT system performance degrades significantly as application distance increases, ambient energy harvesting has become one possible solution to charge up remote sensor nodes. At the same time, RF energy sources are abundant in the environment, however with their low power density, a power interface is necessary for intention of usage. We propose an RF energy harvesting front-end including rectifier and impedance matching network design considerations along with the corresponding EM simulation, PCB design with impedance control for the purpose of minimizing path loss, and S-parameter measurement with fabricated 0.18μm CMOS cross-coupled differential rectifier test chip and test boards. Our goal is to optimize the sensitivity and performance of such RF energy harvesters with input available power ranging from -30dBm to -20dBm, thus producing a DC output voltage for subsequent power management blocks.