Design of On chip Spiral Inductors for Millimeter Wave Frequency Synthesizers

The energy storing element, inductor plays a vital role in CMOS based high frequency integrated circuits, especially in signal generation and impedance matching blocks.An on chip inductor is considered as a critical component because its performance directly impacts the associated circuitry when it is used as a load device or as a matching element. Out of the various requirements of an inductor which resides inside a chip, the inductance value,quality factor and self resonance frequency with smaller area is often preferred. This paper focuses on the lumped model of inductors for high frequency circuits working in the Millimeter wave region from 30 GHz to 300 GHz. For millimeter wave oscillators,inductance value in the range of pico Henry are essential and hence a complete model of an inductor is presented. Using electromagnetic simulator SONNET, all the parameters are extracted. The extracted model is used in the design of an LC Oscillator for millimeter wave band. A Q factor of 26 is achieved for an inductor value close to 153 pH at 60 GHz.The circuits employing this inductor shows promising results when simulated using 45 nm CMOS pdks