A pair of frequency synthesizers from Hittite Microwave Corp. includes integrated voltage-controlled oscillators (VCOs). Models HMC838LP6CE and HMC839LP6CE also incorporate low-noise phase-frequency detectors and dividers and precision charge pumps. The former is tunable over three separate frequency bands: 780 to 950 MHz, 1560 to 1900 MHz, and 3120 to 3800 MHz. It has VCO open-loop phase noise of -88 dBc/Hz at 10 kHz offset from the carrier and -118 dBc/Hz offset 100 kHz from the carrier. The latter is tunable over three separate frequency bands: 1030 to 1210 MHz, 2060 to 2420 MHz, and 4120 to 4840 MHz. It has VCO open-loop phase noise of -85 dBc/Hz at 10 kHz offset from the carrier and -116 dBc/Hz offset 100 kHz from the carrier. The synthesizers consume only 650 mW power. They include 19-b prescalers and 24-b frequency tuning, with typically 3-Hz tuning resolution.