The BW428 from Sainty-Tech Communications Limited is a Voltage Controlled Oscillator with Frequency 9.35 to 10.55 GHz / 4.675 to 5.275 GHz, Power 12.58 mW, Phase Noise -110 dBc/Hz, Phase Noise dBc/Hz @100kHz -110 dBc/Hz, Harmonic Supression -30 dBc. Tags: Die. More details for BW428 can be seen below.