Frank J. Canora

A 2.4-GHz silicon bipolar oscillator with integrated resonator

A 2.4 GHz fully-monolithic silicon-bipolar oscillator circuit implemented in a 12 GHz BiCMOS technology is presented. The integrated resonator circuit uses three different versions of a 2 nH multilevel inductor and a wideband capacitive transformer. The measured Q factor is 9.3 for the three-level inductor. An oscillator phase noise of -78 dBc/Hz is achieved at 20 kHz offset. The circuit dissipates 50 mW from a 3.6 V supply.

Reduction of backgating in GaAs SISFET's with a low-temperature buffer

The use of a low-temperature molecular beam epitaxy (MBE)-grown buffer layer to reduce backgating in GaAs/AlGaAs semiconductor-insulator-semiconductor FETs (SISFETs) is discussed. Comparison with a control wafer having no low-temperature buffer (LTB) reveals an improvement in backgating threshold voltage by a factor of 3, improvement in output conductance and short-channel characteristics, and no significant change in threshold voltage, threshold-voltage spread, and microwave characteristics. The FETs with LTB exhibited increased sensitivity, at 80 K, to trapping of hot electrons.<<ETX>>

A cost-effective approach to a short-range, high-speed radio design in the U-NII 5.x GHz band

High-speed radio design research activities undertaken by the Communications Technology Department at IBMs T.J. Watson Research Center are described. The ultimate goal is to implement a cost-effective, short-range, high-speed radio in the 5-GHz U-NII band and leverage IBMs ultra-high bandwidth SiGe BiCMOS technology.

RF and microwave building blocks in a standard BiCMOS technology

This paper reviews some of the RF IC design activities being undertaken by our group at IBM T.J. Watson Research Center. Hardware results for fully monolithic 2.4 and 4-GHz oscillators, 0.9-2.4 GHz microwave switches and 900-MHz power amplifiers are discussed. The technology employed is a commercially available 0.8-/spl mu/m BiCMOS fabrication process without any modification.

Whip antenna design for portable rf systems

Whip type antennas are probably the most commonly used antennas in portable rf systems, such as cordless and cellular phones, rf enabled laptop computers, personal digital assistants (PDAs), and handheld computers. Whip antennas are almost always mounted on the chassis which contains the radio and other electronics. The chassis is usually a molded plastic which is coated with a conducting paint for EMI purposes. The chassis which appears as a lossy conductor to the antenna, has several effects -- detuning, altering the gain of the antenna, and shadowing its radiation pattern. Extensive modeling and measurements must be performed in order to fully characterize the affects of the chassis on the whip antenna, and to optimize antenna type, orientation and position. In many instances, modeling plays a more important role in prediction of the performance of whip antennas, since measurements become difficult due to the presence of common mode current on feed cables. In this paper models and measurements are used to discuss the optimum choice of whip antennas and the impact of the chassis on radiation characteristics. A modeling tool which has been previously described and has been successfully used to predict radiated field patterns is used for simulations, and measured and modeled results are shown.