Title :
Multiple Turn Ratios of On-Chip Transformer With Four Intertwining Coils
Author :
Heng-Ming Hsu ; Chun-Tsai Chien
Author_Institution :
Electr. Eng. Dept., Nat. Chung-Hsing Univ., Taichung, Taiwan
Abstract :
This paper develops an on-chip transformer in which four coils are entwined tightly within a limited area. The proposed device has a total of six possible turn ratios. The flexibility of the turn ratio facilitates the convenient merging of two transformers with the RF design in a device area. To demonstrate the proposed device, seven devices are fabricated using 90-nm CMOS technology. Measurements reveal that one device has a wide range of turn ratios (n=1-5.8) and coupling coefficients (k=0.61-0.95) within an area of 0.01 mm2. A coil of one of the devices has an inductance of 28.4 nH and conducts with an inductance density of 2840 nH/mm2.
Keywords :
CMOS integrated circuits; transformers; CMOS technology; RF design; four intertwining coil; inductance density; multiple turn ratio; on-chip transformer; size 90 nm; CMOS integrated circuits; CMOS technology; Coils; Couplings; Inductance; Metals; System-on-chip; 90-nm CMOS technology; four coupling coils; inductance density; on-chip transformer;
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2013.2292855
