Differential Bridged-T Coil for Miniature Passive Circuit Design

• Main Authors: Chung-Hsien Chan, 詹忠憲
• Other Authors: Yo-Shen Lin
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/4ax7vm

碩士 === 國立中央大學 === 電機工程學系 === 106 === Abstract In this thesis, very compact integrated passive circuits with high performance are presented. Today, the wireless communication system for multi-band and wide-band is increasing. Therefore, more and more multi-band and wide-band circuit of the basic components or subsystem design concept was presented in the recent year. And the electromagnetic interference (EMI) or RF interference (RFI) issues are important, too. Thus, using a common mode filter to alleviate electromagnetic interference (EMI) or RF interference (RFI) becomes a crucial technique for optimizing the performance of high-speed differential systems. However, the major bottleneck of the size reduction of active and passive microwave circuits is the requirement of multiple transmission lines with given electrical length. The traditional bridge-T coil will be equivalent to the transmission line, but only for single-frequency applications. In this work, the differential and dual-band differential bridged-T coils are used to replace the conventional bridged-T coil, can be used in dual-band microwave passive or more balance circuit design, and while achieving the purpose of minimization. The differential and dual-band differential bridged-T coils can be implemented using inductor and metal-insulator-metal (MIM) capacitor in GaN semiconductor and GaAs semiconductor IC process or Integrated Passive Device (IPD) process to achieve very compact size. It is applied to the design of Miniature wide band and dual wide-band rat-race couplers, common mode band-stop filters (CMF), and an absorptive common mode band-stop filter (ACMF). First of all, the proposed Miniature wide band and dual wide-band rat-race couplers are fabricated in IPD process. The center frequency of the wide band rat-race coupler is at 2.45 GHz. The circuit size of Miniature wide band rat-race coupler is 0.0187〖 λ〗_0×0.0285〖 λ〗_0 at 2.45 GHz. And the center frequency of the dual wide-band rat-race coupler is at 2.45 GHz and 5.5 GHz. The circuit size of Miniature dual wide-band rat-race coupler is 0.0217〖 λ〗_0×0.0321〖 λ〗_0 at 2.45 GHz, 0.0488〖 λ〗_0×0.0721〖 λ〗_0 at 5.5 GHz. Second, the proposed Miniature CMFs were fabricated in three different process. Two CMFs and two wide band CMFs were fabricated in IPD process, then the other two wide band CMFs were fabricated in GaN semiconductor and GaAs semiconductor IC process. All the circuits of above were designed with differential bridge-T coil, and their characteristic impedance were 100 Ω. At first, a wide band CMF fabricated in IPD process whose group delay was 140 ps. The operating frequency of wide band CMF was and 3.57 GHz to 9.18 GHz. The circuit size was 0.03969 x 0.081585 λ_0^2 at the center of the operating frequency. And a wide band CMFs fabricated in GaAs semiconductor IC process whose group delay was 160 ps. The operating frequency was 2.35 GHz to 10 GHz. The circuit size was 0.033 x 0.0452 λ_0^2 at the center of the operating frequency. Finally, the proposed Miniature ACMF was fabricated in IPD process. The characteristic impedance was 100 Ω, and the group delay was 160 ps. The center frequency of Miniature ACMF was 2.4 GHz. The circuit size of Miniature ACMF is 0.01488 λ0 x 0.03176 λ0 at 2.4 GHz. Compared with current designs, the above circuits are smaller in size. The effectiveness of differential and dual band differential bridged-T coils on the design of miniaturized on-chip passive microwave circuit is also validated through proposed design examples.