The NX153EZ from Narda-ATM is a Noise Source with Frequency 1 to 4 GHz, Excess Noise Ratio (ENR) 15.5 dB, Flatness ±0.5 dB, Temperature Coefficient 0.01 dB/Degree C, Voltage Coefficient 0.1 dB/%V. Tags: Module with Connectors. More details for NX153EZ can be seen below.