Abstract—Networking researchers have long faced a fundamental tension between the experimental realism of wireless testbeds on one hand, and the control and repeatability of simulation on the other hand. To overcome the stark tradeoff of these traditional alternatives, we have developed a wireless network emulator that enables both realistic and repeatable experimentation at network scale. A critical component in this emulator is the RF Front End that converts RF signals to lower frequencies - where they can be digitized - and vice versa. We discuss the unique requirements that physical layer network emulation demands of an RF Front End. We present a design that meets these demands and demonstrate its performance via measurements.