Title Page
Abstract
Contents
List of Abbreviations 13
I. Introduction 14
1.1. Low-Voltage, Low-Power Circuits and Systems for UWB Applications 14
1.2. Filter Types and Characteristics 14
1.3. Operational Transconductance Amplifier (OTA) 16
1.4. Filter Synthesis 17
II. Novel Pseudo Differential OTAs 21
2.1. Background and Motivation 21
2.2. Pseudo Differential OTAs and their Characteristics 21
2.3. Established Pseudo Differential OTAs 25
2.3.1. Pseudo Differential OTA with Common-Mode Feedforward 25
2.3.2. Pseudo Differential OTA using Op-Amp to Improve Linearity 27
2.3.3. Optimized Pseudo Differential OTA 29
2.4. Proposed Novel Pseudo Differential OTAs 32
2.4.1. Pseudo Differential OTA using Feedforward Regulator 32
2.4.2. Pseudo Differential OTA using Linearity Improvement technique 40
2.5. Filter Architecture 48
2.6. Simulation Results 50
III. Conclusions 57
References 59
Acknowledgements 62
Curriculum Vitae 63
Table 1. Summary of OTAs simulation results. 56
Table 2. Summary of filters simulation results. 56
Figure 1. Simplified Frontend of IR-UWB Receiver Block Diagram 15
Figure 2. Active Resistor 18
Figure 3. Active Inductor (Gyrator) 19
Figure 4. 3rd-order RLC Chebyshev I LPF Schamatic(이미지참조) 20
Figure 5. 3rd-order Chebyshev I Active LPF Schematic(이미지참조) 20
Figure 6. Fully Differential Structure 22
Figure 7. Pseudo Differential Structure 23
Figure 8. Pseudo Differential OTA with CMFF 25
Figure 9. Pseudo Differential OTA with Linearity Improvement Technique using Op-Amp 28
Figure 10. Common-Mode Control Circuit 30
Figure 11. Pseudo Differential OTA with Simplified CMFB Open-Loop Equivalent Circuit 31
Figure 12. (a) 1st Proposed Pseudo Differential OTA, (b) Common- Mode Feedback(이미지참조) 33
Figure 13. Cross Connected Cascodes 35
Figure 14. Feedforward Offset Caneller Circuit 36
Figure 15. Left half High-Frequency Equivalent Circuit of the 1st OTA(이미지참조) 37
Figure 16. Simplified Eqivalent Circuit Model of the 1st OTA(이미지참조) 39
Figure 17. (a) 2nd Proposed Pseudo Differential OTA, (b) CMFB Circuit(이미지참조) 42
Figure 18. NMOS Cascode Stage 44
Figure 19. Feedforward Offset Canceller Circuit 44
Figure 20. Left half High-Frequency Equivalent Circuit of the 2nd OTA(이미지참조) 45
Figure 21. Simplified Equivalent Circit Model of the 2nd OTA(이미지참조) 47
Figure 22. 9th-order RLC Low-Pass Filter(이미지참조) 49
Figure 23. 9th-order Chebyshev I Low-Pass OTA-C Filter(이미지참조) 49
Figure 24. (a) 1st OTA Transconductance Plot (b) 2nd OTA Transconductance(이미지참조) 51
Figure 25. (a) IIP3 Plot of the 1st OTA, (b) IIP3 Plot of the 2nd OTA(이미지참조) 52
Figure 26. Frequency Response of the Proposed OTAs 53
Figure 27. 9th-order Chebyshev I Low-Pass Filters Frequency Response(이미지참조) 54
Figure 28. Filter Transient Response : (a) Pass Band Plot (350 MHz), (b) Stop Band Plot (650 MHz) 55