The HMC821 from Analog Devices is a Frequency Synthesizer with Frequency 860 MHz to 4.16 GHz, Reference Frequency 10 to 200 MHz, Output Power 12.5 dBm, Supply Voltage 3 to 3.5 V, Current 148 mA. Tags: Surface Mount, PLL Frequency Synthesizer. More details for HMC821 can be seen below.