This application note describes the evaluation board (EVB) and the graphical user interface (GUI) of the STW81101, STW81102 and STW81103 multi-band RF frequency synthesizers (with integrated VCOs). The STW8110x GUI software allows the STW81101, STW81102 and STW81103 synthesizers to be programmed via an I2C/SPI control interface. Three evaluation boards are available depending on the output matching network optimal frequency range: ■ EVB1G (single output - 1 GHz - output divider by 4) ■ EVB2G (single output - 2 GHz - output divider by 2) ■ EVB4G (single output - 4 GHz - direct output)