title page
ABSTRACT
Contents
I. Introduction 14
1.1. Overview 14
1.2. Thesis outline 16
II. Mixer Fundamentals and Topologies 17
2.1. Introduction 17
2.2. Important factors of a mixer 19
2.2.1. Conversion Gain 19
2.2.2. Mixer Noise Figure 20
2.2.3. Linearity 21
2.2.4. Port to port isolations 24
2.2.5. LO power Requirement 25
2.3. Mixer topologies 26
2.3.1. Single transistor active mixers 26
2.3.2. Dual-gate mixer 27
2.3.3. Back-gate mixer 28
2.3.4. Gilbert-cell mixer 29
III. A Low-voltage SiGe HBT Up-conversion Mixer for 5.8GHz WLAN 32
3.1. Introduction 32
3.2. Studies on previous low-voltage mixers 33
3.2.1. Back-gate (bulk or body-input) mixer 33
3.2.2. Transformer-based mixer 34
3.2.3. Folded-switching mixer 35
3.3. The design of low-voltage SiGe HBT up-conversion mixer for 5.8GHz WLAN 36
3.3.1. Design of the low-voltage mixer 36
3.3.2. The operational principles of designed mixer 37
3.3.3. Implementation and Measurement 39
3.4. Summary 45
IV. A novel single-balanced CMOS mixer with current re-use technique. 46
4.1. Introduction 46
4.2. Studies on previous low-power mixers with current re-use technique 47
4.2.1. Gilbert-cell mixer with current reuse technique 47
4.2.2. Even harmonic mixer with current reuse technique 48
4.3. Design of the down-conversion mixer with current reuse technique 49
4.3.1. Design of the basic mixer with only NMOS. 49
4.3.2. Implementation and measurement. 50
4.3.3./4.3.2. Design of the single-balanced mixer with current reuse technique. 53
4.3.4. Implementation and Measurement 57
4.4./4.3. Summary 64
V. Conclusion 66
[국문요약] 68
References 70
Acknowledgement 73
Curriculum Vitae 74
Publications 75
Table 3.1. Measured performances of the up-conversion mixer 44
Table 4.1. Measured performances of the mixer 63
Figure 2.1. A typical architecture of a radio transceiver 17
Figure 2.2. Mixer symbol. 18
Figure 2.3. Graphical representation of the 1dB compression point. 22
Figure 2.4. Graphical representation of the IIP3 and OIP3. 24
Figure 2.5. Single transistor mixers. 26
Figure 2.6. Dual-gate CMOS mixer. 27
Figure 2.7. Back-gate mixer. 28
Figure 2.8. Single balanced Gilbert-cell mixer. 29
Figure 2.9. Double-balanced Gilbert-cell mixer. 30
Figure 3.1. Double-balanced Gilbert-cell mixer. 32
Figure 3.2. NMOS bulk mixer [1]. 33
Figure 3.3. Transformer-based mixer [13]. 34
Figure 3.4. Folded-switching mixer [4]. 35
Figure 3.5. Simplified schematic of the designed mixer 36
Figure 3.6. Equivalent circuit diagram of the designed mixer 37
Figure 3.7. Designed PCB mounted with a mixer chip 40
Figure 3.8. Microstrip line rat-race balun topology 40
Figure 3.9. Measured forward transmission of a 5.8 GHz balun 41
Figure 3.10. Measured phase response of a 5.8 GHz balun 41
Figure 3.11. Measured conversion gain as a function of LO power 42
Figure 3.12. Measured conversion gain as a function of baseband power 43
Figure 3.13. Micrograph of a fabricated mixer with wire bonding 43
Figure 3.14. Measured output spectrum 44
Figure 4.1. Gilbert-cell mixer with current reuse configuration 47
Figure 4.2. Even harmonic mixer with current reuse 48
Figure 4.3. Low-voltage double-balanced mixer cell with only NMOS 49
Figure 4.4. Micrograph of the fabricated chip 51
Figure 4.5. Measured conversion gain as a function of LO power.… 52
Figure 4.6. Measured conversion gain as a function of RF power… 52
Figure 4.7. Two-tone output spectrum with 2MHz offset frequency RF₁〓… 53
Figure 4.8. The proposed novel mixer 54
Figure 4.9. Simplified equivalent circuit with LO+ 56
Figure 4.10. Simplified equivalent circuit with LO- 56
Figure 4.11. Simplified equivalent circuit with LO 57
Figure 4.12. Micrograph of a fabricated PCB for evaluation 58
Figure 4.13. Picture of a fabricated rat-race balun for evaluation 58
Figure 4.14. Measured forward transmission characteristic of a 5GHz balun 59
Figure 4.15. Measured phase response of a 5GHz balun 59
Figure 4.16. Microphotograph of the desinged mixer 61
Figure 4.17. The conversion gain as function of LO power 61
Figure 4.18. Measured conversion gain as function of RF power 62
Figure 4.19. Measured IIP3 62
Figure 4.20. Measured down-converted spectrum with two-tone test 63