Peng Chu

A Planar Bandpass Filter Implemented With a Hybrid Structure of Substrate Integrated Waveguide and Coplanar Waveguide

In this paper, a novel planar bandpass filter is proposed, designed, and implemented with a hybrid structure of substrate integrated waveguide (SIW) and coplanar waveguide (CPW), which has the advantages of good passband and stopband performance inherited from SIW and miniaturized size accompanying with the CPW. Additional design flexibility is introduced by the hybrid structure for efficiently controlling the mixed electric and magnetic coupling, and then planar bandpass filters with controllable transmission zeros and quasi-elliptic response can be achieved. Several prototypes with single and dual SIW cavities are fabricated. The measured results verified the performance of the proposed planar bandpass filters, such as low passband insertion loss, sharp roll-off characteristics at transition band, etc.

Wide Stopband Bandpass Filter Implemented With Spur Stepped Impedance Resonator and Substrate Integrated Coaxial Line Technology

A novel wide stopband bandpass filter implemented with spur stepped impedance resonator (SSIR) and substrate integrated coaxial line (SICL) technology is proposed in this letter. SSIR possesses capabilities of both suppressing and staggering spurs without complicated fine-tuning, and SICL is very suitable for wide stopband applications. A prototype with compact size is fabricated, and the measured results exhibit extended stopband up to 8.76 f0 with a rejection better than 40 dB (except for a little 36.5 dB burr in 7.06 f0), or 9.36 f0 with rejection better than 30 dB.

Balanced Substrate Integrated Waveguide Filter

A novel balanced filter realized in the form of substrate integrated waveguide (SIW) is proposed and studied in this paper. Based on the inherently horizontal and vertical symmetry of the SIW, this filter presents inherently high-performance balanced property with advantages of no identical pair requirement, being free from the limitation of symmetrical topology, easy and flexible design, high common-mode (CM) suppression, and robust CM suppression when comparing with conventional counterparts. Several prototypes are designed, fabricated, and measured to verify the expected properties.

Dual-Mode Substrate Integrated Waveguide Filter With Flexible Response

This paper proposes a novel dual-mode substrate integrated waveguide (SIW) filter technique. Based on the conventional dual-mode SIW structure, further investigation is performed. Multiple transmission zeros can be obtained at one side or both sides of the passband for an SIW cavity. Therefore, flexible design and high performance response can be available for dual-mode SIW filter. A dual-mode SIW bandpass filter with quasi-elliptic response and a dual-mode SIW diplexer with asymmetric channel response are simulated, fabricated, and measured to demonstrate and verify the novel property.

Miniaturized wide stopband bandpass filter using in-resonator stub

This paper proposes a novel in-resonator stub technology on designing wide stopband bandpass filter with miniaturized size. The open stubs are directly embedded in the tapped resonator to eliminate the spurs in the stopband without additional circuit occupying or complicated process. On having the wide stopband character, without obviously interfering with the resonance character of the embedded resonator, the design complexity and flexibility of the filter using in-resonator stub is not significantly affected comparing with classical filter design. A series of miniaturized wide stopband bandpass filters using in-resonator stub are designed, fabricated, and measured.

Miniaturized wide-stopband bandpass filter with high performance and easy design

This article proposes a miniaturized wide-stopband bandpass filter on the combination of substrate integrated coaxial line (SICL) and in-resonator stub those possess superiority at wideband application and stopband extension respectively. Employing standard PCB process, high performance stopband with considerable suppression and extension is available, while corresponding design is fairly simple and straightforward.

A novel Spur Stepped Impedance Resonator

This paper propose a novel Spur Stepped Impedance Resonator (SSIR). Developed from the classical Stepped Impedance Resonator (SIR) without additional or complicated circuit occupying, almost keeping the same compact size and quality factor, the SSIR has tunable spurious resonances while keeping fundamental resonance frequency almost unchanged, and a tapped SSIR will produce tunable transmission zeros without interfering with the fundamental resonance or the loaded quality. A simple demo application of SSIR on designing bandpass filter with extended stopband is proposed, fabricated and measured.