I-Q Signal Generation Techniques for Communication IC Testing and ATE Systems

Transcription

1 2016 IEEE International Test Conference I-Q Signal Generation Techniques for Communication IC Testing and ATE Systems M. Murakami, H. Kobayashi, S. N. B. Mohyar O. Kobayashi, T. Miki, J. Kojima Gunma University Universiti Malaysia Perlis D-Clue Tech, formerly STARC

2 2/50 Research Objective To develop usage of complex multi-band signals for LSI testing applications To develop digital centric design of complex multi-band signal generator - Multi-bit ΔΣ DA modulator - Linearity enhancement algorithms

3 3/50 Outline Background to This Research Complex Multi-Band Signals Complex Multi-BP ΔΣ DA Modulators DWA Algorithm Self-Calibration Combination of DWA and Self-Calibration Conclusions

4 4/50 Outline Background to This Research Complex Multi-Band Signals Complex Multi-BP ΔΣ DA Modulators DWA Algorithm Self-Calibration Combination of DWA and Self-Calibration Conclusions

5 5/50 Research Goal Demand for low cost testing of communication IC High quality I,Q test signal generation for receiver IC with low cost

6 6/50 Outline Background to This Research Complex Multi-Band Signals Complex Multi-BP ΔΣ DA Modulators DWA Algorithm Self-Calibration Combination of DWA and Self-Calibration Conclusions

7 7/50 Complex Signal 2 Real signals Iin, Qin Complex signal Iin + j Qin j = -1 Complex signal processing is NOT complex. - Prof. Ken Martin, Toronto Univ.

8 Complex Signal in Frequency Domain Complex signal Iin + j Qin After Fourier transform Iin(j ω) + j Qin (j ω) Asymmetric Complex Negative freq. 0 Positive freq. 8/50

9 IC Testing with Multi-tone Signal ADSL ADC Testing empty 9/50

10 10/50 IC Testing with Complex Multi-tone Signal Complex Analog Filter Testing Complex filter gain

11 IC Testing with Complex Multi-tone Signal I-Q ADCs Testing I-Q ADCs in receiver circuit 11/50

12 IC Testing with Complex Multi-tone Signal Image Rejection Ratio Testing of Communication ICs I, Q imbalance Negative freq. (input) Suggested by an ATE vendor Positive freq. (output) 12/50

13 IC Testing with Complex Signal Clock phase fine adjustment system using complex signal Suggested by an ATE vendor 13/50

14 14/50 IC Testing with Complex Signal High frequency signal generation 3

15 15/50 Outline Background to This Research Complex Multi-Band Signals Complex Multi-BP ΔΣ DA Modulators DWA Algorithm Self-Calibration Combination of DWA and Self-Calibration Conclusions

16 16/50 I,Q Signal Generation 1 Analog centric bit DSP 2 Digital centric(1) 1 3 bit DSP 3 Digital centric(2) DSP 1 3 bit Proposed

17 17/50 1 Analog Centric bit DSP Nyquist DAC Large Nyquist-rate DACs and Steep analog filters

18 Delta Sigma DA Converter Real vs Complex 2 2 Real-BP ΔΣ DACs signal noise signal noise 1 3 bit DAC 3 1 Complex-BP ΔΣ DAC Unused band noise Signal band signal 1 3 bit DAC Wider signal band, High SNR 18/50

19 Complex Delta Sigma is Superior SNDR Signal to Noise and Distortion Ratio Real signal noise signal noise Complex noise signal OSR : Oversampling Ratio 15 db better SNDR for complex BP ΔΣ modulator High quality I, Q signals 19/50

20 I,Q Signal Generation DSP + ΔΣ DAC + Complex = Low cost, high quality signal! Digital rich! 20/50

21 Principle of Complex BP Noise Shape 21/50

22 Principle of Complex BP Noise Shape 22/50

23 Principle of Complex BP Noise Shape 23/50

24 2nd-order Complex Multi-BP ΔΣ DAC 24/50

25 25/50 N th -order Complex Resonator H(z)

26 26/50 Outline Background to This Research Complex Multi-Band Signals Complex Multi-BP ΔΣ DA Modulators DWA Algorithm DWA: Data Weighted Averaging One of Dynamic Element Matching (DEM) algorithms

27 27/50 Multi-bit DA Modulator Analog filter Quantization noise

28 Multi-bit DAC 28/50

29 Multi-bit DAC 29/50

30 Multi-bit DAC + DWA 30/50

31 31/50 Effect of DWA Steep notch at DC

32 Equivalent Circuit of Complex DWA 32/50

33 Equivalent Circuit Implementation 33/50

34 Complex Multi-Bandpass DWA Algorithm 34/50

35 Simulation Result ~Ideal Linear DAC~ 35/50

36 Simulation Result ~Actual Nonlinear DAC~ 36/50

37 Simulation Result ~ Actual Nonlinear DAC + DWA ~ 37/50

38 38/50 Outline Background to This Research Complex Multi-Band Signals Complex Multi-BP ΔΣ DA Modulators DWA Algorithm Self-Calibration Combination of DWA and Self-Calibration Conclusions

39 Look Up Table 39/50

40 DAC Nonlinearity Measurement 40/50

41 ΔΣ DAC with Self-Calibration of DAC1, DAC2 41/50

42 ΔΣ DAC with Self-Calibration of DAC1, DAC2 42/50

43 Simulation Results 43/50

44 44/50 Simulation Results When DAC nonlinearity is large, self-calibration (3) is more effective than DWA(2).

45 45/50 Pros and Cons of Self-Calibration with delta-sigma ADC is required.

46 46/50 Outline Background to This Research Complex Multi-Band Signals Complex Multi-BP ΔΣ DA Modulators DWA Algorithm Self-Calibration Combination of DWA and Self-Calibration Conclusions

47 47/50 Combination of DWA and Self-Calibration LP case

48 48/50 Combination of DWA and Self-Calibration LP case For large variation, combination of DWA and self-calibration is the best.

49 49/50 Outline Background to This Research Complex Multi-Band Signals Complex Multi-BP ΔΣ DA Modulators DWA Algorithm Self-Calibration Combination of DWA and Self-Calibration Conclusions

50 Conclusion I-Q signal generation with digital centric Complex multi-bp ΔΣ DAC Multi-bit DAC 〇 Relaxes analog filter requirements x Degrades system linearity DWA algorithm Self-calibration algorithm Their combination Low cost, high quality I-Q signal generation. 50/50

51 Back Up 51/50

52 Type of DWA 52/50

53 Simulation Result ~ Actual Nonlinear DAC + DWA ~ 53/50

54 Simulation Conditions : DAC unit cell variation Standard deviation 1.0% 54/50

55 DWA = ΔΣ 55/50