by Meng Wei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 115-119). / Abstracts in English and Chinese. / Abstract / Acknowledgements / Table of Contents / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Overview of Microwave Filter --- p.1 / Chapter 1.2 --- Introduction to Synthesis and Diagnosis of Generalized Chebyshev Coupled Resonator Filters --- p.3 / Chapter 1.3 --- Original Contributions --- p.5 / Chapter 1.4 --- Thesis Organization --- p.6 / Chapter 2. --- Fundamental Theory --- p.7 / Chapter 2.1 --- Generalized Chebyshev Polynomial --- p.7 / Chapter 2.2 --- Cross Coupled Resonator Network --- p.19 / Chapter 2.3 --- N x N Coupling Matrix Synthesis --- p.22 / Chapter 2.4 --- Similarity Transformation --- p.28 / Chapter 2.5 --- N + 2 Transversal Network Synthesis --- p.34 / Chapter 2.6 --- Example --- p.39 / Chapter 2.7 --- Summary --- p.46 / Chapter 3. --- Analytical Diagnosis of Narrow-Band Coupled Resonator Filters --- p.47 / Chapter 3.1 --- Introduction --- p.47 / Chapter 3.2 --- Extended Realizability Conditions --- p.50 / Chapter 3.3 --- Filter Circuit Model Extraction with Finite Q Value --- p.57 / Chapter 3.4 --- Diagnosis of a Dual-Mode Circular Waveguide Filter --- p.64 / Chapter 3.5 --- Diagnosis of a In-Line Waveguide Filter --- p.69 / Chapter 3.6 --- Application in Tuning a Sixth Order Dual-Mode Filter --- p.74 / Chapter 3.7 --- Future Work --- p.82 / Chapter 3.8 --- Summary --- p.83 / Chapter 4. --- Hybrid Synthesis of Microwave Coupled Resonator Filters --- p.84 / Chapter 4.1 --- Introduction --- p.84 / Chapter 4.2 --- A Hybrid Approach --- p.86 / Chapter 4.3 --- Matrix Transformations --- p.90 / Chapter 4.4 --- Application of Proposed Method --- p.94 / Chapter 4.5 --- Future Work --- p.100 / Chapter 4.6 --- Summary --- p.101 / Chapter 5. --- Conclusion --- p.102 / Appendix --- p.104 / References --- p.115 / Author's Publications --- p.120

Thesis (M.S.)--Ohio University, November, 1989. / Title from PDF t.p.

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Hil-Yee Chan, Walter. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 84-87). / Abstracts in English and Chinese. / Chapter Chapter 1 --- introduction --- p.3 / Chapter Chapter 2 --- Background Theory --- p.6 / Chapter 2.1 --- Maximally Flat Filter Response --- p.6 / Chapter 2.2 --- Equal-Ripple Filter Response --- p.8 / Chapter 2.3 --- Low-pass to Band-pass Transformation --- p.9 / Chapter 2.4 --- Impedance and Admittance Inverter --- p.10 / Chapter 2.5 --- Coupled-Resonator Filter --- p.14 / Chapter Chapter 3 --- Active Filter Employing Negative Resistance --- p.18 / Chapter 3.1 --- Lossy Coupled-Resonator Filter --- p.18 / Chapter 3.2 --- Common-source Capacitive Feedback Configuration --- p.21 / Chapter 3.3 --- Active LC-resonator --- p.23 / Chapter 3.4 --- Design Criteria of the Active Filter --- p.24 / Chapter Chapter 4 --- Intermodulation Analysis --- p.27 / Chapter 4.1 --- IM Distortion of the Negative Resistance Circuit --- p.27 / Chapter 4.2 --- Analysis of the Active Coupled-Resonator Filter --- p.30 / Chapter 4.3 --- IM Distortion Power of a Nth Order Active Filter --- p.32 / Chapter Chapter 5 --- Noise Analysis --- p.37 / Chapter 5.1 --- Noise Basics and Noise Figure --- p.37 / Chapter 5.2 --- Noisy Two-Ports --- p.41 / Chapter 5.3 --- Correlation Matrix Representation of Noisy Two-Ports --- p.44 / Chapter 5.4 --- Change of Representation --- p.46 / Chapter 5.5 --- Interconnection of Noisy Two-Ports --- p.47 / Chapter 5.6 --- Correlation Matrix of the Basic Two-Ports --- p.48 / Chapter 5.7 --- Extraction of the Noise Parameters of MESFET --- p.51 / Chapter 5.8 --- Noise Parameters of CFY30 --- p.53 / Chapter 5.9 --- Noise Figure of CFY30 --- p.56 / Chapter Chapter 6 --- Noise Analysis of Passive and Active Filter --- p.60 / Chapter 6.1 --- Noise Current Generated by the Negative Resistance Circuit --- p.60 / Chapter 6.2 --- Noise Figure of the Passive Filter --- p.63 / Chapter 6.3 --- Noise Figure of the Active Filter --- p.65 / Chapter 6.3.1 --- Noise Figure of a Second-order Active Filter --- p.65 / Chapter 6.3.2 --- Noise Figure of the Higher-order Active Filter --- p.68 / Chapter 6.4 --- Design consideration of Active Filter with Optimized Noise and Linearity Performance --- p.71 / Chapter Chapter 7 --- Design of 900MHz Hybrid Active Filter --- p.73 / Chapter 7.1 --- Schematic of Active Filter --- p.73 / Chapter 7.2 --- Design Variants --- p.75 / Chapter 7.3 --- Measurement Results --- p.75 / Chapter 7.3.1 --- Passive Filter --- p.75 / Chapter 7.3.2 --- Active Filter --- p.78 / Chapter Chapter 8 --- Conclusion and Future Work --- p.83 / Reference --- p.84 / Author's Publications --- p.88

Novel feedback signal interference concept for bandpass filter (BPF) design is proposed in this thesis. This new concept was utilized to design wide stopband BPF with superior performance for WLAN applications. The proposed filtering structure consists of two simple coupled-line couplers. The first coupler was employed within the main signal path and the second coupler which is open circuited at the opposite ends was used for the feedback circuit. This new filtering structure was fabricated using low temperature co-fired ceramic technology. The fabricated BPF exhibits an insertion loss (IL) of -1.3 dB with a 3dB fractional bandwidth of 13% at a centre frequency of 2.4 GHz. Furthermore, an attenuation level of -15 dB is achieved up to 4.7fo. Using stepped impedance coupled-lines in the feedback; the stopband performance of the proposed structure can be significantly improved while keeping passband performance intact. Furthermore, the feedback signal interference concept proved to be versatile and can be used to design high selectivity microstrip BPF using composite right/left handed transmission line unit cell in the feedback circuit. The measured results show that roll-up/down rate of more than 300 dB/GHz can be achieved with low IL.The spectrum based quality factor for CRLH TL based BPF is explored and thoroughly studied in this thesis to design a low phase noise oscillator. The proposed metamaterial BPF has higher spectrum based quality factor within the left-handed region due to the slow-wave propagation. This intriguing feature enables the design of a free-running oscillator with excellent phase noise performance operating at a frequency of 2.05 GHz. The fabricated oscillator demonstrates a phase noise of -126.7 dBc/Hz at 100 kHz frequency offset and a FOM of -207.2 dBc/Hz at a 1 MHz frequency offset, being one of the very best reported so far. Many microstrip multi-band BPF design techniques are presented in the literature that offers superior performance in terms of IL, 3dB FBW, and high selectivity. These methods mainly lack the ability to obtain high performance with compact size. Coupled slotted open stubs are used to design a miniaturized dual-wideband BPF. Interdigital capacitor and inner open stubs are used to improve rejection level within the stopbands and increase selectivity. The measurement results reveal that the fabricated dual-wideband BPF has two passbands with a 3dB FBW of 117% and 36%, at respective centre frequencies of 1 GHz and 6.65 GHz. The filter has a super compact size (0.09 Gammag × 0.05 Gammag) where Gammag denotes the guided wavelength at the centre frequency of the first passband and exhibits an attenuation level greater than 20 dB up to 12 GHz.

The focus of this thesis is on developing theories and techniques to extract lossy microwave filter parameters from data. In the literature, the Cauchy methods have been used to extract filters’ characteristic polynomials from measured scattering parameters. These methods are described and some examples are constructed to test their performance. The results suggest that the Cauchy method does not work well when the Q factors representing the loss of filters are not even. Based on some prototype filters and the relationship between Q factors and the loss, we conduct preliminary studies on alternative representations of the characteristic polynomials. The parameters in these new models are extracted using the Levenberg–Marquardt algorithm to accurately estimate characteristic polynomials and the loss information.

Hu, Hai. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Meng, Meng. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (p. [100]-102). / Abstract also in Chinese. / List of tables --- p.iii / List of figures --- p.iv / Introduction --- p.1 / Chapter 1.1 --- Overview of Microwave filters --- p.1 / Chapter 1.2 --- tuning of Microwave filters --- p.3 / Chapter 1.3 --- Rationalization of measured data --- p.6 / Chapter 1.4 --- Contributions of this thesis --- p.8 / Chapter 1.5 --- Organization of this thesis --- p.10 / Coupling matrix extraction methods --- p.11 / Chapter 2.1 --- Basics for coupling matrix synthesis --- p.11 / Chapter 2.2 --- Lossless coupling matrix extraction --- p.14 / Chapter 2.3 --- Lossy coupling matrix extraction --- p.17 / Chapter 2.3.1 --- Effects of dissipation factor --- p.18 / Chapter 2.3.2 --- Determination of dissipation factor --- p.21 / Approximation method single pole --- p.21 / Adjustment method by complex Y parameters --- p.22 / Chapter 2.3.3 --- Coupling matrix synthesis method with loss --- p.25 / Chapter 2.3.4 --- Relations between residues --- p.28 / Chapter 2.4 --- Case of degenerated poles --- p.29 / Chapter 2.4.1 --- The determination of poles --- p.30 / Y parameters interpolation method --- p.30 / Interpolation of denominator of Y parameter --- p.32 / Vector fitting method --- p.34 / Chapter 2.4.2 --- The determination of residues --- p.35 / Data rationalization --- p.39 / Chapter 3.1 --- Quasi-SB-AFS interpolation --- p.40 / Chapter 3.2 --- Removal of phase loading --- p.40 / Asymptote of phase using S parameters --- p.43 / Asymptote of phase using low-pass circuit model --- p.45 / Method of phase loading removal --- p.47 / Chapter 3.3 --- De-embedding of the reference plane --- p.49 / Examples of coupling matrix extraction --- p.57 / A 4th degree DR filter --- p.57 / A 6th degree waveguide filter --- p.62 / An 8th degree waveguide filter --- p.63 / A 10th degree waveguide filter --- p.66 / Filter tuning utilizing coupling matrix extraction --- p.69 / Chapter 5.1 --- Filter tuning strategies --- p.69 / Chapter 5.2 --- Filter tuning examples --- p.71 / Conclusions and discussions --- p.81 / APPENDIX A: Time domain tuning --- p.83 / APPENDIX B: ACME User´ةs Manual --- p.87 / Chapter B.1 --- ACME basics --- p.87 / Chapter B.2 --- Installations --- p.89 / Chapter B.3 --- Getting started --- p.90 / Chapter B.4 --- A hello world example --- p.97 / bibliography --- p.100

近半个世纪来，大量精力致力于研究针对满足不同需求的滤波器综合设计理论。对基于解析方法的滤波器综合设计理论的需求，源源不断的推动着这个课题的研究与发展。传统滤波器综合理论假设滤波器网络两端口终端阻抗相同并且均为不随频率变化的纯实阻抗，该假设等效于认为滤波器两端匹配到具有相同特征阻抗的无耗传输线。但对于一些实际应用，例如多工器中信道滤波器的设计，滤波器的其中一个端口需要匹配到随频率变换的复阻抗 。本篇论文提出了一种适用于广义切比雪夫带通滤波器复阻抗匹配的解析综合方法用于设计一端匹配负载为频率变换的复阻抗而另一端匹配负载为常数实阻抗的滤波器。该方法以功率波再归一化理论为依据并假设：（1） 指定的传输零点不变 （2）反射零点始终纯虚数轴上。本论文通过端口参考阻抗的再归一化，推导出定义滤波器在不同参考阻抗的散射参数的特征多项式之间的三个关系并证在保证网络可实现性的前提下该关系只能通过一个理想的滤波器电路加上一段适合长度的位于滤波器与复阻抗之间的传输线来满足。设计匹配复阻抗的滤波器网络的关键在于保证电路的可实现性的前提下最大程度满足匹配条件。 本篇论文证明了为满足上述要求，引入一段最优长度的传输线的必要性。从在一定频率范围内最大限度匹配复阻抗的角度考虑，引入的传输线长度能够最优确定。论文中所提出的解析且灵活的设计方法可应用于多工器或双工器中信道滤波器的设计。通过具体的设计实例与全波软件的仿真，该方法的可行性得到了验证。 / A great deal of effort has been devoted to the synthesis of microwave filters with required characteristic over the past half century. The driving force to this subject is the demand of analytical solution that facilitates various filter design requirements. Conventional filter synthesis approach assumes the termination impedance of a filter network at both ports is a real constant matched load, which is equivalent to a matched transmission line with same characteristic impedance. But for practical applications such as designing a channel filter of a multiplexer, the filter is required to match a frequency variant complex load at one port. This thesis presents an analytical approach to the synthesis of a general Chebyshev filter that matches to a frequency variant complex load at one port and a real constant load at the other port based on power wave renormalization theory under two practical assumptions: (1) the prescribed transmission zeros are stationary; and (2) the reflection zeros are located along imaginary axis. Three necessary conditions that stipulate the characteristic polynomials associated to the filter are derived through renormalization of the load reference impedances. It has been shown that these three conditions can only be satisfied by an ideal filter circuit model separated by a piece of transmission line from the complex load. The key issues in the synthesis approach are to enforce the realizability conditions of a filter network and to match the complex load with a best effort. For this purpose, it is proved that a section of transmission line with an optimal length must be inserted between the filter network and the complex load. The length of the transmission line will be optimally designed in the sense that the designed filter will best match to the complex load over a given frequency range. The proposed method offers a deterministic yet flexible way for optimally designing a diplexer or a multiplexer with a realistic loading effect. The effectiveness of the method is demonstrated by a number of design examples. / Detailed summary in vernacular field only. / Meng, Huan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 114-116). / Abstracts also in Chinese. / ABSTRACT --- p.i / ACKNOWLEDGEMENTS --- p.v / Table of contents --- p.iv / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Overview of Microwave Filters --- p.1 / Chapter 1.2 --- Introduction to Filter Synthesis --- p.3 / Chapter 1.3 --- Contributions of this Thesis --- p.6 / Chapter 1.4 --- Organization of this Thesis --- p.7 / Chapter Chapter 2 --- Review of Direct Filter Synthesis Theory --- p.8 / Chapter 2.1 --- Basic Properties of Characteristic Polynomials --- p.8 / Chapter 2.2 --- Derivation of General Chebyshev Polynomial --- p.15 / Chapter 2.3 --- Analysis of Cross Coupled Resonator Circuit --- p.27 / Chapter 2.4 --- Synthesis of N+2 Transversal Coupling Matrix --- p.35 / Chapter 2.5 --- Reconfiguration of coupling topology --- p.44 / Chapter 2.6 --- Summary --- p.50 / Chapter Chapter 3 --- Direct Synthesis of Microwave Bandpass Filters with A General Loading Effect --- p.51 / Chapter 3.1 --- Introduction --- p.51 / Chapter 3.2 --- Renormalization of Reference Impedance --- p.56 / Chapter 3.3 --- The Direct Synthesis Approach --- p.65 / Chapter 3.4 --- Examples --- p.72 / Chapter 3.4.1 --- Example 1: synthesis with frequency invariant complex load --- p.73 / Chapter 3.4.2 --- Example 2: synthesis with frequency variant complex load --- p.74 / Chapter 3.4.3 --- Example 3: synthesis with a highly reactive complex load --- p.77 / Chapter 3.5 --- Future work --- p.80 / Chapter 3.6 --- Summary --- p.81 / Chapter Chapter 4 --- Design Examples of RF/Microwave Diplexers --- p.82 / Chapter 4.1 --- Introduction --- p.82 / Chapter 4.2 --- Non-contiguous band diplexer design --- p.85 / Chapter 4.2.1 --- Example 1: Diplexer Design Using an H-plane T-Junction --- p.85 / Chapter 4.2.2 --- Example 2: Diplexer Design with a wired Y-junction --- p.92 / Chapter 4.3 --- Discussion on designing a contiguous diplexer --- p.96 / Chapter 4.4 --- Future work --- p.101 / Chapter 4.5 --- Summary --- p.102 / Conclusion --- p.103 / Chapter Appendix I --- : Power Wave Renormalization Theory --- p.104 / Chapter Appendix II --- : Necessary and Sufficient condition of Power Conservation for Objective S --- p.109 / Proof of Sufficiency --- p.109 / Proof of Necessarity --- p.111 / References --- p.114 / Publication --- p.117