| dc.description.abstract | In this thesis, very compact integrated passive circuits with high performance are presented. Today, the wireless communication system for multi-band demand is increasing. Therefore, more and more multi-band circuit of the basic components or subsystem design concept was presented in the recent year. 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 dual-band bridged T-coil is used to replace the conventional bridged T-coil, can be used in dual-band microwave passive circuit design, and While achieving the purpose of minimization. The dual-band bridged T-coil 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 then applied to the design of m Miniature dual-band branch-line coupler, dual-band Wilkinson power divider, and a triple-band absorptive band-stop filter (ABSF).
First of all, the proposed Miniature dual-band branch-line coupler and dual-band Wilkinson power divider are fabricated in IPD process. The center frequency of both are 2.45 GHz and 5.5 GHz. The circuit size of Miniature dual-band branch-line coupler is 0.0123〖 λ〗_0×0.0245〖 λ〗_0 at 2.45 GHz, 0.0275〖 λ〗_0×0.055〖 λ〗_0 at 5.5 GHz. And the circuit size of Miniature dual-band Wilkinson power divider is 0.0145〖 λ〗_0×0.0133〖 λ〗_0 at 2.45 GHz, 0.0333〖 λ〗_0×0.0305〖 λ〗_0 at 5.5 GHz.
Finally, the proposed Miniature triple-band ABSF is fabricated in two different process. At first, a single-band 7.2 GHz ABSF was designed with a conventional bridge T-coil, then a dual-band ABSF was designed with a dual-band bridge T-coil. The center frequency of dual-band ABSF was 4.8 GHz and 9.6 GHz. In the last, I cascade two filter which I described to a triple-band ABSF. The stop-band frequency of triple-band ABSF was 4.8 GHz, 7.2 GHz and 9.6 GHz. The circuit size of triple-band ABSF which is fabricated in IPD process is 0.038〖 λ〗_0×0.04〖 λ〗_0 at 4.8 GHz, 0.058〖 λ〗_0×0.06〖 λ〗_0 at 7.2 GHz and 0.077〖 λ〗_0×0.08〖 λ〗_0 at 9.6 GHz. And the circuit size of triple-band ABSF which is fabricated in GaAs semiconductor IC process is 0.0272〖 λ〗_0×0.0368〖 λ〗_0 at 4.8 GHz, 0.0407〖 λ〗_0×0.0552〖 λ〗_0 at 7.2 GHz and 0.0543〖 λ〗_0×0.0736〖 λ〗_0 at 9.6 GHz.
Compared with current designs, the above circuits are smaller in size. The effectiveness of dual-band bridged T-coil on the design of miniaturized on-chip passive microwave circuit is also validated through proposed design examples, and in a single circuit to achieve dual-frequency characteristics. | en_US |