Title :
A temperature-compensated CMOS LC-VCO enabling the direct modulation architecture in 2.4GHz GFSK transmitter
Author :
Tanzawa, T. ; Shibayama, H. ; Terauchi, R. ; Hisano, K. ; Ishikuro, H. ; Kousai, S. ; Kobayashi, H. ; Majima, H. ; Takayama, T. ; Agawa, K. ; Koizumi, M. ; Hatori, F.
Abstract :
The frequency drift of an open-loop PLL is an issue for direct modulation applications such as Bluetooth transceivers. The drift mainly comes from the temperature variation of the VCO during the TX operation. In this paper, we propose the optimum location of the VCO, considering the temperature gradient through full-chip thermal analysis. Moreover, a novel temperature-compensated VCO by employing a new biasing scheme is proposed. The combination of these two techniques enables power reduction of the transmitter by 33% without sacrificing performance.
Keywords :
Bluetooth; CMOS analogue integrated circuits; UHF oscillators; compensation; frequency shift keying; phase locked loops; radio transmitters; voltage-controlled oscillators; 2.4 GHz; Bluetooth transceiver; CMOS LC-VCO; GFSK transmitter; TX operation VCO temperature variation; biasing scheme; full-chip thermal analysis; open-loop PLL frequency drift; temperature gradient; temperature-compensated VCO; transmitter direct modulation architecture; transmitter power reduction; Bluetooth; Energy consumption; Frequency; Modulation; Phase locked loops; Temperature control; Temperature dependence; Transceivers; Transmitters; Voltage-controlled oscillators;
Conference_Titel :
Custom Integrated Circuits Conference, 2004. Proceedings of the IEEE 2004
Print_ISBN :
0-7803-8495-4
DOI :
10.1109/CICC.2004.1358796
