Chi-Ping Chou

Bio: Chi-Ping Chou is an academic researcher from National Taiwan University. The author has contributed to research in topics: Microstrip & Band-pass filter. The author has an hindex of 1, co-authored 1 publications receiving 238 citations.

Microstrip diplexers design with common resonator sections for compact size, but high isolation

Abstract: High isolation and compact size microstrip diplexers designed with common resonator sections have been proposed. By exploiting the variable frequency response of the stepped-impedance resonator, resonators can be shared by the two filter channels of the desired diplexer if their fundamental and the first spurious resonant frequency are properly assigned. Size reduction are, therefore, achieved by introducing a few common resonator sections in the circuit. This concept has been verified by the experimental results of two diplexer circuits. One of the diplexers is composed of two three-pole parallel-coupled bandpass filters and the other is composed of two four-pole cross-coupled bandpass filters, which are formed by only five and six resonators, respectively. Both of them occupy extremely small areas while still keeping good isolations. Good agreements are also achieved between measurement and simulation.

Development of Millimeter-Wave Planar Diplexers Based on Complementary Characters of Dual-Mode Substrate Integrated Waveguide Filters With Circular and Elliptic Cavities

Abstract: A novel high-performance millimeter-wave planar diplexer is developed based on the complementary characters of substrate integrated waveguide (SIW) dual-mode filters with circular and elliptic cavities by making the tradeoff between the isolation, insertion loss, and selectivity. The responses of the dual-mode SIW circular and elliptic cavities are first investigated. It can be found that the upper side response of the circular cavity and the lower side response of the elliptic cavity are very steep. The diplexers with high isolation performance are then designed based on the complementary response characters of circular and elliptic cavities. A diplexer with two dual-mode SIW circular and elliptic cavities is designed and fabricated with a normal printed circuit board process. The measured insertion losses are 1.95 and 2.09 dB in the upper and lower passbands centered at 26 and 25 GHz with the fractional bandwidths of 5.2% and 5.4%. The isolation is lower than - 50dB

Compact and Low Loss Dual-Band Bandpass Filter Using Pseudo-Interdigital Stepped Impedance Resonators for WLANs

Abstract: In this letter, pseudo-interdigital stepped impedance resonators (PI-SIRs) are used to design the bandpass filter (BPF) with dual-band response. By tuning the impedance ratio (K) and physical length of SIRs, the BPF has good dual-passband performances at 2.4/5.2GHz and high isolation between the two passbands. It is shown that the dual-band BPF has a smaller area and lower insertion loss in comparison of previous works. Good agreement is shown between the full-wave electromagnetic simulation and the measurement

High Isolation and Compact Diplexer Using the Hybrid Resonators

Abstract: In this letter, a compact microstrip diplexer with very high output isolation is proposed. This diplexer consists of compact hybrid resonators, which are capable of introducing transmission zeros at desired frequencies and meanwhile suppressing signals below the resonant frequencies through tapping the feeding line close to the shorted vias. By designing the transmission zero of the lower-frequency channel in the higher passband, and utilizing the high lower-stopband suppression property of the higher-frequency channel, very high diplexer output isolation can be achieved. The proposed diplexer with center frequencies at 1.8 and 2.45 GHz, respectively, has demonstrated better than 55 dB output isolation and more than 55 dB suppressions in the stopbands. Furthermore, the diplexer occupies only a small area of 0.13λ0 × 0.2λ0.

Compact and High-Isolation Diplexer Using Dual-Mode Stub-Loaded Resonators

Abstract: A novel compact microstrip diplexer for UMTS and WCDMA system is proposed in this letter. The diplexer is mainly composed of three dual-mode stub-loaded microstrip resonators. Two resonant modes of a stub-loaded resonator work together with one mode produced by the common stub-loaded resonator to form a passband or operating band of the proposed diplexer. Extensive study is then conducted on coupling scheme involved in various parts of the diplexer. In particular, the resonance of a resonator is employed to create a desired transmission zero in the stopband, thus improving the isolation between two passbands. The proposed diplexer is in final fabricated and measured. A good agreement between EM simulated and measured results evidently validates the proposed methodology.

Microstrip Diplexer Design Using Common T-Shaped Resonator

Abstract: This study presents a novel microstrip diplexer with a joint T-shaped resonator. The T-shaped resonator has an extremely small frequency ratio using microstrip with practical line width. Additionally, the T-shaped resonator can be used as a frequency selective signal splitter, making it feasible to design a diplexer for a system with two extremely close bands. The diplexer using a joint T-shaped resonator does not require combining circuits and matching networks. A diplexer used in the UMTS-WCDMA system is designed and measured. The proposed diplexer has high isolation and wide stopband in addition to satisfying the passband requirement. A satisfactory agreement between the simulated results and the measured results validate the proposed configuration.