| Summary: | 博士 === 長庚大學 === 電子工程學系 === 99 === This thesis mainly classified into three research topics. At first, one focuses on implementations and analyses of miniaturized and low-loss chip filters using CMOS technologies. And then, one miniaturized chip filter is integrated with a low noise amplifier (LNA) to validate integrated possibility and improve poor frequency selection of CMOS LNA, and new synthesized method is also proposed to realize such filter. Finally, analysis of a tri-band dual-mode ring filter is discussed, and new design equations and its equivalent model are also presented.
In the beginning, a second-order inductive-coupled chip filter is investigated and fabricated in a standard 0.18-μm CMOS technology. To shrink the layout dimension and reduce dielectric loss on standard silicon substrate, high-impedance coplanar waveguide and metal-insulator-metal structure are adopted to realize inductive and capacitive elements of such filter. Meanwhile, a tunable source-load coupling capacitor is combined into the filter to produce two adjustable transmission zeros for improving the poor frequency selection of the low-order filter. Rejection capability of the circuit configuration in stopbands is comparable to high-order filter while maintaining low insertion loss. To provide more transmission zeros, the cross-coupled technique is also applied to one second-order filter with asymmetrically compact resonators to produce three deep transmission zeros in a standard 0.13-μm CMOS technology.
Traditionally, suppression capabilities of CMOS LNAs in both sides of stopbands are insufficient, so that strong image signals may be received by mixed-frequency circuits along with weak RF signals that causes signal-to-noise ratio to be largely degenerated. To improve this problem; consequently, the X-band miniaturized filter is also integrated with a two-staged self-biased low noise amplifier (LNA) to sharpen frequency selection. Based on even- and odd-mode half circuit analysis, some new formulas are developed to exactly calculate all component values of the inductive-coupled filter. The self-biased circuitry of the LNA eliminates use of external gate biases and provides appropriate voltages to different gates of transistors to achieve an optimal noise figure and reduce power dissipation of the first-staged amplifier.
Multi-band filters are widely employed in modern multi-standard wireless communication systems for obtaining ability of accessing multiple operation bands and lowering entire overhead. In the final topic of the thesis, so one will focuses on the analysis and design of the tri-band dual-mode ring filter. In addition, new design formulas are developed to accurately determine all component values of dual-mode ring filter with arbitrary length ratio. To design the chip filter to meet 60-/77-/100-GHz unlicensed wireless applications, it causes the layouts of the three ring resonators to place close to each other, so that the performance of the filter is degenerated by coupling effects. To consider the tight coupling effects, a new equivalent circuit is developed and inherent capacitor is used to approximate the coupling effects. This prototype is implemented with 0.5-μm pHEMT technology and measurement results show that the insertion losses of the chip filter in the three bands are 2.4 dB, 2.7 dB, 3.5 dB, respectively. Their return losses are greater than 18 dB, 17 dB, and 8 dB, respectively.
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