Low-Power Phased Array Control Technologies

The silicon-germanium heterojunction bipolar transistor (SiGe HBT) is the first practical bandgap-engineered device to be realized in silicon. SiGe HBT technology combines transistor performance competitive with III-V technologies with the processing maturity, integration levels, yield, and hence, cost commonly associated with conventional Si fabrication. In the seventeen years since the first demonstration of a functional transistor, SiGe HBT technology has emerged from the research laboratory, entered manufacturing on 200-mm wafers, and is poised to enter the commercial RF and microwave market. State of-the-art SiGe HBT's can deliver: 1. fT in excess of 90 GHz; 2. fmax in excess of 120 GHz 3. minimum noise figure below 1.5 dB at 10.0 GHz 4. 1/f noise corner frequencies below 500 Hz. 5. cryogenic operation 6. excellent radiation hardness 7. reliability comparable to Si. A host of record-setting digital, analog, RF, and microwave circuits have been demonstrated in the past several years using SiGe HBT's, and recent work on passives and transmission lines on Si suggest a migratory path to Si-based monolithic microwave integrated circuits (MMIC's) is possible. The combination of SiGe HBT's with advanced Si CMOS to form a SiGe BiCMOS technology represents a unique opportunity for Si-based RF system-on-a-chip solutions.