Title :
Novel symmetric-structure switchable differential inductor design
Author :
Tsai, Pei-Kang ; Chen, Yu-Ting ; Huang, Tzuen-Hsi
Author_Institution :
Dept. of Electr. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan
Abstract :
A novel symmetric layout structure is proposed for a switchable differential inductor (SWD-inductor). The proposed structure overcomes the problem of quality factor degradation encountered when using SWD-inductors in the traditional quadrangular spiral layout. On the basis of the substrate loss density distribution predicted by an electromagnetic (EM) wave simulator, the reason for the quality factor improvement in our proposed novel SWD-inductor structure is interpreted. Two testkeys with the novel and the traditional layout structures are fabricated using 0.18-¿m RF CMOS technology. Under identical criterion of area consumption and inductance values for the testkeys, the experimental data show that our proposed structure improves the quality factor by 41% at 1.8 GHz when the switch is turned off and by 24% at 7.5 GHz when the switch is turned on.
Keywords :
CMOS analogue integrated circuits; Q-factor; inductors; radiofrequency integrated circuits; RF CMOS technology; electromagnetic wave simulator; frequency 1.8 GHz; frequency 7.5 GHz; quadrangular spiral layout; quality factor degradation; substrate loss density distribution; symmetric layout structure; symmetric-structure switchable differential inductor design; CMOS technology; Degradation; Electromagnetic scattering; Inductors; Predictive models; Q factor; Radio frequency; Spirals; Switches; Testing; Differential inductor; quality factor; substrate loss; switchable inductor;
Conference_Titel :
Microwave Conference, 2009. APMC 2009. Asia Pacific
Conference_Location :
Singapore
Print_ISBN :
978-1-4244-2801-4
Electronic_ISBN :
978-1-4244-2802-1
DOI :
10.1109/APMC.2009.5385507
