A 0.98 to 6.6 GHz Tunable Wideband VCO in a 180 nm CMOS Technology for Reconfigurable Radio Transceiver Yusaku Ito, Hirotaka Sugawara, Kenichi Okada, and Kazuya Masu Integrated Research Institute, Tokyo Institute of Technology, Japan Conclusion Impact Measurement results 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 Varactor control voltage [V] Oscillation frequency [GHz] 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 2 f o 3/2 f o f o 3/4 f o 1/2 f o Normalizing VCO phase noise (L{f offset }) by center frequency (f o ), power consumption (P dc ) and frequency tuning range (FTR). FOM T − = + ⋅ − = 10 20 10 10 20 FTR FOM P FTR f f f L Hz dBc FOM DC offset o offset T log log log } { ] / [ − = + ⋅ − = 10 20 10 10 20 FTR FOM P FTR f f f L Hz dBc FOM DC offset o offset T log log log } { ] / [ 1mW The proposed wideband LC-VCO achieves the widest tuning range, and the best FOM T simultaneously using pure CMOS technology. -60 -30 -40 -50 Power [dBm] Freq. [Hz] IMRR = 20.2 dB Vgain A = 1.36 V -35.5 dBm(1.36 V) -37.5 dBm(1.32 V) -36.5 dBm(1.34 V) -39.0 dBm(1.28 V) -55.7 dBm Vgain A = 1.34 V -48.7 dBm Vgain A = 1.32 V -43.7 dBm Vgain A = 1.28 V -40.7 dBm Rejection 3/2f o (2.93 GHz) 1/2f o (0.98 GHz) Phase noise Tuning range Spurious rejection (the combiner output) Detail of proposed VCO Background -210 -200 -190 -180 -170 -160 -150 -140 -130 0 20 40 60 80 100 120 140 160 0 -200dBc/Hz -190dBc/Hz -180dBc/Hz -170dBc/Hz -160dBc/Hz FOMt = FTR [%] FOM [dBc/Hz] Our previous work (A-SSCC 2005) Better performance Pure CMOS Technology CMOS with MEMS SOI CMOS BiCMOS SiGe-BiCMOS × × This work 10k 100k 1M 10M Offset frequency [Hz] -40 -60 -80 -100 -120 -140 -160 Phase noise [dBc/Hz] 1.85 GHz ( 3/ 4 f o ) 2.50 GHz ( f o ) 5 .13 GHz ( 2 f o ) 3.40 GHz ( 3/2 f o ) 1.13 GHz ( 1/2 f o ) 1/2 Div Differential VCO Divider DSBM Divider Switch f o 1/2 Div f o f o f o f o or 1/2f o 1/2f o and 3/2f o DC and 2f o 2f o Reject spur A A A B B B S Vin_1 S Vin_2 S Vout = AS Vin_1 +BS Vin_2 Gain Control AS Vin_1 BS Vin_2 S Vout 1/2f o 1/2f o 3/2f o 3/4f o 1/2f o 180 1/2f o 3/2f o 0 3/2f o + = A Switch turn to Variable Gain Combiner Variable Gain Combiner TSMC 0.18 µm CMOS process with RF option Supply voltage : Total current : 1.8 V 2.45 ~ 14.9 mA FTR = 149 % FOM = - 202 ~ - 206 [dBc/Hz] T Reconfigurable Analog RF Circuit PA LNA LO LPF DAC PGA ADC SW I Q FD LPF 1/N VCO MIX MIX LPF PLL Baseband LSI RF Front-end - On-chip RF Transceiver with Direct-Conversion Architecture - Mobile Communication Device ・ More multi-band/mode functions ・ Smaller size ・ Lower power operation A Multi-band RF front-end implemented in a single chip is required. 800MHz - 6GHz A differential LC-VCO and a double side-band mixer and utilized instead of a QVCO and a SSMB . The proposed wideband VCO can achieve wide tuning range 0.98 - 6.64 GHz with sufficient phase noise. 6.64 GHz 0.98 GHz FTR = f - f f center max min 540 µ m 800 µ m We use the Differential VCO instead of QVCO. We can achieve the wide tuning range and low phase noise with smaller layout area. Tuning-range extension technique (Using LC-VCO, divider and mixer) I t c a n a c h i e v e t h e w i d e t u n i n g r a n g e w i t h s u f f i c i e n t p h a s e n o i s e . . Wideband VCO is an indispensable component to achieve the multi-band RF front-end. Purpose of this work