Seok-Woo Choi

Multilevel monolithic 3D inductors on silicon

This paper has been the analysis of passive devices in Si RF and microwave. Multilevel monolithic 3D inductors implemented in a standard CMOS technology are presented. Since on-chip inductors are constrained to be planar, the typical solution is to form a spiral. Proposed inductors are composed of 3D structures requiring no extra processing steps. Inductances are higher in increasing the mutual inductance besides the self-inductance. In this reason, this structure gives rise to a quality factor Q and a inductance using 3D geometry in small areas.

Some prominent characteristics of the modified inverse Chebyshev function

The modified inverse Chebyshev function exhibits progressively diminishing ripples in the stopband. The modified inverse Chebyshev function can be realizable using the doubly-terminated ladder network for the order n even or odd. Besides the doubly-terminated ladder network realizability, lower pole-Q values of the modified inverse Chebyshev function are accountable for improved time delay characteristic, preferable time domain performance, and low pole-Q sensitivity as compared with the classical inverse Chebyshev function.

Design of CMOS composite transistors with improved operating region

Proposes two new CMOS composite transistors with an improved operating region by reducing a threshold voltage. The proposed composite transistors 1 and 2 employ a p-type folded composite transistor and an electronic Zener diode in order to decrease the threshold voltage, respectively. The simulation has been carried out using 0.25/spl mu/m n-well process with 2.5V supply voltage.

Low voltage CMOS transconductors using the series composite transistor

In this paper, low voltage CMOS transconductors using the series composite transistors are presented. The minimum input voltage of the designed circuits is V/sub Tn/, which is suitable for low supply voltage. The designed circuits have been simulated by HSPICE using 0.25 /spl mu/m n-well CMOS process. Simulation results show that THD is less than 1.2% for the differential input signal of up to 1.5V/sub p-p/ when the input signal frequency is 10 MHz.