Ryan Lee Bunch

Quality factor and inductance in differential IC implementations

Monolithic inductors are widely used in microwave ICs and RFICs. Design considerations for inductors on low-resistivity substrates have been described. A /spl pi/-equivalent model, used to account for various loss mechanisms, can be helpful in understanding differences in the definition of L and Q for single-ended and differential structures that exist in the literature. Specific uses for the equations in this article have been outlined. The L and Q for an example monolithic, differential inductor were extracted from measured two-port S-parameters using equations for differential configurations on low-resistivity substrates.

A 0.35 /spl mu/m CMOS 2.5 GHz complementary -G/sub M/ VCO using PMOS inversion mode varactors

A fully integrated VCO has been fabricated in a standard single poly 4-metal 0.35 /spl mu/m 3.3 volt digital CMOS process, using a complementary negative G/sub M/ topology. PMOS inversion-mode varactors are used for frequency tuning. A phase noise of -97 dBc/Hz at 100 kHz offset has been measured using a single-ended test setup. The measured tuning range is 16 percent. Unbuffered and buffered versions of the oscillator were fabricated on the same die. The buffered version has an output power of nearly 0 dBm. The unbuffered core of the oscillator has a power dissipation of 35 mW.