The R&S®ESR3 from Rohde & Schwarz is a RF Spectrum Analyzer with Frequency 9 kHz to 3.6 GHz, Frequency Resolution 10 Hz to 10 MHz, Resolution Bandwidth 10 Hz to 10 MHz, P1dB 3 dBm, AC Supply 100 to 240 VAC. Tags: Analyzer with Screen. More details for R&S®ESR3 can be seen below.