1. Measurement of Integrated PA-to-LNA Isolation on Si CMOS Chip Ryo Minami ， JeeYoung Hong ， Kenichi Okada ， and Akira Matsuzawa Tokyo Institute of Technology, Japan

2. 1 2010/12/10 R. Minami, Tokyo tech. Outline Tx leakage and problem Evaluation of Tx leakage –Tx leakage paths –Measurement and Simulation method Result Conclusion

3. 2 2010/12/10 R. Minami, Tokyo tech. Background Merit –High frequency characteristic –High supply voltage Demerit –Chip area and cost CMOS transistors can provide a sufficient performance for PA design. The level of Tx leakage increases. To investigate Tx leakage paths. Conventionally, Power Amplifier (PA) has been implemented by compound semiconductors. CMOS technology has been developed.

4. 3 2010/12/10 R. Minami, Tokyo tech. Tx leakage and problem FDD system The large transmitted signal leaks to Rx input side. Tx leakage causes IM and degrades demodulation quality.

5. 4 2010/12/10 R. Minami, Tokyo tech. Tx leakage paths substrate coupling inductor coupling wire coupling (Vdd, GND) conventionalsingle-chip The integration of the PA with other blocks increases many coupling paths.

6. 5 2010/12/10 R. Minami, Tokyo tech. Dicing Substrate coupling and inductor coupling are generated because PA and LNA are integrated on the same chip. Substrate coupling is blocked by physically separating the PA and LNA[1]. [1] J.Y. Hong et al., IEICE society Conference, 2009.

7. 6 2010/12/10 R. Minami, Tokyo tech. Measurement method substrate coupling inductor coupling After dicing, the distance between PA and LNA is 0.74mm, 1.55mm, 2.37mm, 3.20mm.

8. 7 2010/12/10 R. Minami, Tokyo tech. Specification of the designed PA and LNA PA LNA PALNA Technology 0.18  m CMOS process Frequency5 GHz V DD 3.3 V1.8 V Gain at 5 GHz5.5 dB15.1 dB NF at 5 GHz2.7 dB Area1.01mm×1.01mm0.70mm×1.01mm

9. 8 2010/12/10 R. Minami, Tokyo tech. Simulation method Magnetic coupling simulation by HFSS (an electromagnetic field simulator) Circuit simulation with magnetic coupling effect by goldengate The magnetic coupling between the inductor at PA output side and the inductor at LNA input side is the most dominant. Assume

10. 9 2010/12/10 R. Minami, Tokyo tech. Simulation result Gain of PA and LNA are shown at 5 GHz S 21 depends on the distance between PA and LNA

11. 10 2010/12/10 R. Minami, Tokyo tech. Under 3 GHz –Thermal noise from the resistance of LNA –Noise floor of the network analyzer Around 5 GHz –Noise floor of the network analyzer with gain Over 8 GHz –Probe coupling exists. Assume Measurement result

12. 11 2010/12/10 R. Minami, Tokyo tech. Noise floor and probe coupling ● Noise floor ● Probe coupling S 21 with 3 cm distance between probes and 2cm distance between probe and absorber Noise floor S 21 with 4 patterns of probe distance and 0.3mm distance between probe and absorber Probe coupling

13. 12 2010/12/10 R. Minami, Tokyo tech. Probe coupling problem ● The case of measuring chip ● The case of measuring probe coupling Signal flows into the chip. This is the worst case of probe coupling.

14. 13 2010/12/10 R. Minami, Tokyo tech. Thermal noise from the resistance of LNA : noise calculation point k: 1.38*10 -23 [J/K] T: 300 [K] B: 10 [Hz] Cable loss:2 [dB]

15. 14 2010/12/10 R. Minami, Tokyo tech. Result of error analysis (higher and lower side) Under 3 GHz –Noise floor of the network analyzer Over 8 GHz –Probe coupling exists.

16. 15 2010/12/10 R. Minami, Tokyo tech. Around 5 GHz –Noise floor of network analyzer with gain Result of error analysis (middle section) sim.: dotted meas.: solid

17. 16 2010/12/10 R. Minami, Tokyo tech. Comparison of coupling data at 5 GHz The isolation value of inductor coupling is affected by the noise floor of the NA over 1.8mm distance between PA and LNA. Total isolation value becomes smaller than that of the duplexer over 0.4mm Substrate coupling is the most dominant factor in Tx leakage.

18. 17 2010/12/10 R. Minami, Tokyo tech. Conclusion Substrate coupling is the most dominant factor in Tx leakage for Si substrate. Total isolation value becomes smaller than that of the duplexer over 0.4mm distance between PA and LNA. Error sources in measurement are noise floor of the network analyzer and probe coupling.

19. 18 2010/12/10 R. Minami, Tokyo tech. Thank you for your attention!

20. 19 2010/12/10 R. Minami, Tokyo tech. probe coupling The distance between inductor is blue line. The distance between probe is red line.

21. 20 2010/12/10 R. Minami, Tokyo tech. Comparison at 5 GHz

22. 21 2010/12/10 R. Minami, Tokyo tech. Neumann’s formula The mutual inductance is given by the double integral Neumann formula. M : Mutual inductance d : distance 「 Study of the different coupling mechanisms between a 4GHz PPA and a 5-7GHz LC- VCO 」 ー S.Bronckers ， G.Vandersteen ， L.De Locht ， G.Van der Plas ， Y.Rolain ， 2008IEEE RFICS

23. 22 2010/12/10 R. Minami, Tokyo tech. The effect of probe coupling

24. 23 2010/12/10 R. Minami, Tokyo tech. The specification of PA and LNA The reason why the L equal to 0.35 um is that the oxide film is very thick.