Equipment manufactures have been increasingly demanding space and cost-efficient solutions for radio applications with frequencies in the microwave range. A single-chip RF synthesizer with integrated voltagecontrolled oscillators (VCOs) is planning to fulfill that need with operation up to 5 GHz. Dubbed the STW81103, it has measured phasenoise performance of 0.27 deg. root mean square (RMS) at 1.16 GHz, 0.6 deg. RMS at 2.33 GHz, and 1.5 deg. RMS at 4.67 GHz with a frequency step of 200 kHz. In addition, the synthesizer’s embedded VCOs with automatic center-frequency calibration promise to provide multi-band functionality. A single device spans frequency bands from 625 to 762.5 MHz, 1087.5 to 1525 MHz, 2175 to 3050 MHz, and 4350 to 5000 MHz. As a result, wireless system suppliers can use the device in both wideband and multi-band applications. To cover the largest frequency range from 625 MHz to 5 GHz, these integrated RF synthesizers need just three devices (the STW81101, STW81102, and STW81103).