The impact of digital noise coupling through the substrate on RF MOSFETs was investigated in terms of the noise figure (NF) of the device up to 26.5 GHz. Previous works on the substrate digital noise coupling have treated the effect mostly in terms of the electrical isolation between ports, rather than actual devices, which does not provide direct information on the degradation of actual device performance parameters from such coupling. In this work, an actual NMOSFET was employed for test and the effect was described in terms of NF, a practical device performance parameter. The results show that NF is significantly degraded as the device enters the weak inversion state and/or V ds becomes smaller, suggesting a trade-off between low power operation and immunity against the substrate noise coupling. Also, it is experimentally verified that devices with a dual guard ring showed much smaller NF than those with a single guard ring.
Bibliographical noteFunding Information:
Manuscript received May 31, 2009; revised June 15, 2009. First published August 11, 2009; current version published September 02, 2009. This work was supported by ‘Next-generation growth engine’ project of MCIE and the National Program for Tera-Level Nanodevices of the Ministry of Education, Science and Technology as one of the 21 century Frontier Programs. Y. Oh and J.-S. Rieh are with the School of Electrical Engineering, Korea University, Seoul 136-701, Korea (e-mail: email@example.com). S. Lee is with Kasan R&D campus, LG electronics, Seoul 153-802, Korea. C. H. Park is with the Department of Electronics and Communications Engineering, Kwangwoon University, Seoul 139-701, Korea. Digital Object Identifier 10.1109/LMWC.2009.2027064 Fig. 1. Simulated structures (a) and resultant (b). Realistic CMOS process conditions were employed for the TCAD. Large and small are for the actual dimension of 20-and 5-finger RF MOSFETs, respectively, both with unit finger dimension of 0.13 m 2.0 m. For resistive coupling, large and V condition is used.
- Guard ring
- Noise figure
- Substrate coupling
- Substrate noise
ASJC Scopus subject areas
- Condensed Matter Physics
- Electrical and Electronic Engineering