Power Amplifier Nonlinearity Analysis and Millimeter-wave Sub-harmonically Pumped Mixer Circuit Designs
Date Issued
2006
Date
2006
Author(s)
Chen, Shih-Yu
DOI
en-US
Abstract
Due to interests in Multi-media services and personal wireless communication systems, fast and wideband data transmission is getting demanded than ever before. However, frequency band is getting crowded as well. To utilize the limited bandwidth effectively, modern digital communication systems tend to use complex digital modulation schemes which have stringent linearity specifications for the transceivers.
Power amplifier nonlinearity analysis and Millimeter-wave nonlinear circuit design and are the main research point of this thesis. We present an analytical expression to show correlation between the IM3R and the ACPR for W-CDMA signal based on PDF observation. The calculable constant correlation applies to all kinds of amplifiers and applies to distorted region above P1dB as long as the IM5R is 10dB lower than IM3R. For up-link W-CDMA, the constant correlation Co is fixed at 8 dB, while the constant Co is fixed at 2 dB for down-link W-CDMA. Besides W-CDMA, PDF influence other kinds of signals. For QPSK signal, the constant Co is 6 dB, while the constant Co is 4 dB for 16-QAM, 64-QAM and 128-QAM signals.
After all the discussion and derivation for signals at microwave frequency, we apply our expression to millimeter-wave frequency band. The measured results show all the constant correlation for different modulated signals hold even if the carrier frequency is at millimeter-wave frequency, and our prediction of ACPR by IM3R measurements achieves. To conclude all the measurement and calculation, the value of constant Co does not vary with circuits, carrier frequency and channel bandwidth of signals, but does vary with modulation types of signal of different PDF.
On the other hand, for circuit designs, a 38-48-GHz miniature sub-harmonically pumped diode mixer with low LO input power is presented. Quasi-lumped matching topology is employed to minimize the chip size which is 0.72mm2. Additionally, a miniature Q-band monolithic subharmonically pumped resistive mixer was developed. The compact RF/IF diplex circuit and a reduced-size balun were used to minimize the chip size which results 0.72 mm2 as well. From the measurement results, the resistive mixer has the same conversion loss as the diode mixer, but has better linearity characteristics than the diode mixer.
Subjects
次諧波混頻器
毫米波
鄰近通道功率比
subharmonically pumped mixer
millimeter-wave
adjacent channel power ratio
Type
thesis