Above 200 GHz On-Chip CMOS Frequency Generation, Transmission and Receiving Bassam Khamaisi and Eran Socher Department of Physical Electronics Faculty of Engineering Tel-Aviv University
Outline Background and Motivation Signal Generation at 209-233 GHz Circuit topology Fundamental generation 3 rd harmonic generation 3 rd harmonic extraction Measurement results Signal Transmission at 210-227 GHz Transmitter characterization Full CMOS Imaging System at 220 GHz Receiver at 270 GHz
Motivation and Application MMW Sub-MMW Material Transmission Applications Spatial Resolution Homeland security detection of explosives Tumor Detection www.teraview.com 3
Why are Sub-MMW Systems Challenging? THz gap working at sub-mmw or THz currently relies on either multiplying RF/mm-wave III-V-based sources or mixing optical sources. Component and system cost. D. Huang et al, IEEE JSSC, vol. 43, pp. 2730-2738, 2008.
Challenges to Sub-MMW Systems Based on CMOS Why CMOS? CMOS is promising technology due to 1. Low cost 2. High level integration CMOS challenges on sub-mmw The main challenge is signal generation with: 1. High output power 2. Wide tuning range Limitation of power amplification at sub-mmw band. Most of reported signal sources on CMOS suffer from low power and frequency bandwidth.
Challenges to Sub-MMW Systems Based on CMOS Signal source at 410GHz E. Seok et al, ISSCC Dig. Tech. Papers, p.472, 2008. Power about 15nW and tuning range of 3GHz (0.73%). Not sufficient for practical applications.
Proposed Approach: Using Harmonics Harmonics approach: Generating frequencies beyond the process f max by using higher harmonics of a fundamental MMW CMOS source. Advantages: 1. Improved frequency tuning (done at fundamental). 2. Exploiting the transistor non linearity to generate powerful signals beyond f max.
390 µm Signal Source at 209-233GHz Signal source based on differential Colpitts VCO V dd V g GND G S G 440 µm
Signal Source at 209-233GHz Signal source based on differential Colpitts VCO Fundamental generation 3 rd harmonic generation 3 rd harmonic coupling This topology achieves at fund: 1. Wide tuning range. 2. High output power. (Electronic Letters, Socher and Jameson, 2011) Several roles for the transistors: Introduce negative resistance to compensate tank loss. Buffer stage between tank and load. Frequency tuning by controlling bias point. Power matching to load stage.
Signal Source- Oscillation Analysis Barkhausen criteria Re Z ReZ 0 ImZ active ImZ 0 active res res Oscillation start-up Resonance
Signal Source- Oscillation Analysis Gate signal Fundamental generation Signal at output Output spectrum
Signal Source- Amplitude Behavior Model Transistor i-v model I ds gs t gs t 0 k V V V V 0 else Fundamental generation Due to inherent transistor non-linearity: I cos 0 0 kv cos 2 2 2 0 else 1 0 ds V V 0 gs0 t cos 2 V 1 V t I 0 0 V 1 0 t t Gate voltage Drain current I ( ) I I cos I cos 2 I cos3 ds 0 1 2 3
Signal Source- Amplitude Behavior Model Fundamental generation The large signal trans-conductance: G M I k 1 0 sin0 V1 2 In oscillation, the open loop gain at SS A ( s j ) G X G R 1 l 0 M T X ( sj ) R M T G M T 1 R T 0 T The tank trans-impedance X T V I out in R T describes the real trans-resistance R T Q 0 eff C eff 13
Signal Source- Amplitude Behavior Model Fundamental generation kv1 I1 0 sin0 2 Fundamental voltage Fundamental current 14
Signal Source- Amplitude Behavior Model 3 rd harmonic generation I kv sin 1 0 3 1cos0 6 3 rd harmonic current G M A sufficient current magnitude in the 3 rd harmonic. 15
Signal Source- Transformer 390 µm Transformer XF challenges: V dd XF G 1. Providing high enough impedance to generate powerful fundamental and create a significant 3 rd harmonic current. V g GND 440 µm S G 2. Coupling the 3 rd harmonic to the load. XF 3D layout Load Out XF modeling Transistors drains IN
Signal Source- Transformer 3 rd harmonic coupling XF equivalent model Z XF _ S N sc p3 sl 1 1 N a 1 s 0 s Single ended transformer Z XF _ S 1 s 1.2C p3 3 rd harmonic coupling by parasitic capacitor.
Signal Source- Measurement 390 µm Fundamental tone of signal source around 75GHz V dd V g GND G S G 440 µm Pout = -2dBm @ 75GHz Phase noise = -91.15 dbc/hz @ 1MHz Offset
Frequency [GHz] Signal Source at 209-233GHz Output power [dbm] 390 µm V dd V g GND G S G 235 230 V dd =1.2V V dd =1.4V V dd =1.6V V dd =1.8V -5-10 440 µm 225-15 220 215 210 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 V g [V] Tuning range=24ghz (10.6%) -20-25 V dd =1.2V V dd =1.4V V dd =1.6V V dd =1.8V -30 205 210 215 220 225 230 235 Frequency [GHz] Maximum output power -6.2dBm B. Khamaisi and E. Socher, IEEE MCWL, Vol. 22, No. 5, 2012.
Signal Source at 209-233GHz Comparison of state of the art sources above 200GHz Ref. Type Tech. Freq. [GHz] Output power [dbm] Tuning Range [GHz] PN @ 1MHz offset [dbc/hz] Chip size [mm 2 ] DC power [mw] This work 3 rd Harmonic generation 90 nm CMOS 228-6.2 24-90.5 (est.) 0.1716 77.4 [3] Triplepush 0.13µm CMOS 256-17 NA -88 (est.) 0.052 71 [3] Triple- Push 65 nm CMOS 482-9 NA -76 0.0303 27.5 [2] Funda -mental InP 254-8 NA NA 0.16 11.7 [1] Superposition 90 nm CMOS 324-46 4-78 (est.) 0.0378 * 12
Signal Source at 209-233GHz References [1] D. Huang, T. R. LaRocca, M. C. F. Chang, L. Samoska, A. Fung, R. L. Campbell, and M. Andrews, "Terahertz CMOS Frequency Generator Using Linear Superposition Technique," Solid-State Circuits, IEEE Journal of, vol. 43, pp. 2730-2738, 2008. [2] V. Radisic, X. B. Mei, W. R. Deal, W. Yoshida, P. H. Liu, J. Uyeda, M. Barsky, L. Samoska, A. Fung, T. Gaier, and R. Lai, "Demonstration of Sub-Millimeter Wave Fundamental Oscillators Using 35-nm InP HEMT Technology," Microwave and Wireless Components Letters, IEEE, vol. 17, pp. 223-225, 2007. [3] O. Momeni and E. Afshari, "High Power Terahertz and Millimeter-Wave Oscillator Design: A Systematic Approach," Solid-State Circuits, IEEE Journal of, vol. 46, pp. 583-597.
390 µm Signal Generation and Transmission Signal source at 209-233GHz V dd V g G S Signal Generation GND G 440 µm Transmitter at 210-227GHz Signal Transmission
Transmitter at 210-227GHz
Transmitter Characterization Transmitter power on-top at 217GHz (at 4mm distance) Measurement B. Khamaisi, S. Jameson, and E. Socher, IEEE T-TST, vol. 3, 2013.
Detected power [dbm] Transmitter Characterization EIRP [dbm] Detected power on-top at 217GHz (at 4mm distance) -20 2.5-25 -30-35 -2.5-7.5-12.5 EIRP P A RX eff 4 πr 2-40 -17.5 Measured maximum EIRP= +1.8dBm -45 205 210 215 220 225 230 Freqeuncy [GHz] -22.5 Frequency drop of 13% between simulation and measurement. B. Khamaisi, S. Jameson and E. Socher, IEEE T-TST, vol. 3, 2013.
Transmitter at 210-227GHz Comparison of state of the art transmitters above 200GHz Ref. This work This work [1] [2] [1] Signal source type on TX Colpitts VCO and 3 rd Harm. Gen Colpitts VCO and 3 rd Harm. Gen Cross coupled push-push VCO Cross coupled push-push VCO Push- Push VCO Tech. 90nm CMOS 90nm CMOS 65nm CMOS 65nm CMOS 130nm SiGe Freq. [GHz] 217 217 300 191.2 170 Directivity [db] 13.1 10.6 10 11 - EIRP [dbm] +2.8 +1.8-1 -1.9 - P T_Rad [dbm] -10.3-8.8-12.7 - - - T.R. [GHz] 17 17-3.6 - TX chip size (with pads) [mm 2 ] P DC [mw] Si bulk [µm] 0.531 134 80 0.531 122 280 0.64 75-1.1 77 - - - -
Transmitter at 210-227GHz References [1] E. Laskin, P. Chevalier, A. Chantre, B. Sautreuil, and S. P. Voinigescu, 165-GHz Transceiver in SiGe Technology, IEEE JSSC, vol. 43, pp. 1087-1100, 2008. [2] K. Sengupta and A. Hajimiri, Sub-THz beam-forming using near-field coupling of Distributed Active Radiator arrays, in IEEE RFIC, pp. 1-4, 2011. [3] K. Sengupta and A. Hajimiri, Distributed active radiation for THz signal generation, in IEEE ISSCC, pp. 288-289, 2011.
Full CMOS Imaging System at 220GHz Imaging System at 220GHz Optical Image Receiver 220 GHz Power Transmission Transmitter A. Lisauskas, B. Khamaisi, S. Boppel, M. Mundt, V. Krozer, E. Socher and H. G. Roskos, IRMMW-THz, September 2012.
Receiver at 270 GHz 65 nm CMOS (fmax 210 GHz ) On-Chip LO LO based 3 rd harmonic generation Mixer: single transistor Chip size: 470 µm x 470 µm Simulations CG [db] S11 [db] Freq. [GHz] VdLO=2.0 V VdLO=1.8 V VdLO=1.6 V VgLO [V]
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