The EFM959-M131 is a frequency multiplier module manufactured by Teledyne Aerotech, Inc. It is a precision, frequency multiplication device designed to generate output frequencies from 2 to 4 times that of the input signal. It is frequency agile, with an operating frequency range of 500 KHz-1GHz, pulse input duration of 10 µs or greater, and a high direct third harmonic signal. It features a high linearity, low phase noise, and low group delay variation, making it suitable for frequency conversion, precision mixing, signal generation, signal replication, and frequency synthesis. The module operates from +5V and requires no external components, making it a plug-and-play solution for a variety of applications.