Kang-Chun Peng

High-performance frequency-hopping transmitters using two-point delta-sigma modulation

This paper presents a 2.4-GHz high-performance frequency-hopping (FH) transmitter using two-point delta-sigma modulation (TPDSM). Two bottleneck problems in the implementation have been studied rigorously. One is the nonlinear performance of a phase-locked loop (PLL). The other is the inherent gain and delay mismatches between two modulation points. Both nonlinear and mismatch factors dominate the modulation accuracy in the closed PLL. Our formulation can predict the dependencies of modulation accuracy on both factors quite successfully. Comparison of the averaged frequency deviation and frequency-shift-keying (FSK) error between theory and measurement shows excellent agreement. The implemented TPDSM-based FH Gaussian FSK transmitter can achieve 2.5-Mb/s data rate along with 15-/spl mu/s PLL stable time with only 2.2% FSK error under good design and operating conditions.

S-parameter formulation of quality factor for a spiral inductor in generalized two-port configuration

This paper formulates various quality (Q) factors associated with the applications of on-chip spiral inductors to radio-frequency integrated circuits using S-parameters. The formulations start with the Q factor of a spiral inductor in a generalized two-port configuration based on a new complex-power approach and then extend to the Q factors of a tank and matching circuits that use the spiral inductors. In the demonstration, the two-port S-parameters for a series of CMOS spiral inductors have been measured to further generate such various Q factors for a many-sided evaluation of the inductor performance.

A novel EER transmitter using two-point delta-sigma modulation scheme for WLAN and 3G applications

A novel transmitter architecture is proposed for wireless local area networks (WLAN) and 3/sup rd/ generation (3G) mobile applications. The transmitter is based on the envelope elimination and restoration (EER) architecture applied with two-point delta-sigma modulator (TPDSM). It can integrate digital modulators and power amplifiers without mixers effectively. In addition, the power amplifier can deal with non-constant envelope modulations like QPSK highly efficiently.

The effects of path-delay mismatch on GFSK transmitters with a dual-port architecture

In this paper, a low-cost dual-port architecture for GFSK transmitters is investigated for its sensitivity to the path-delay difference between two data ports. The simulation results show that the architecture can achieve a high data rate but encounter significant modulation distortion due to the mismatch in path delay when the frequency deviation is close to the PLL natural frequency.