Compact Third-Order Microstrip Bandpass Filter Using Hybrid Resonators

• In this paper, a novel microwave bandpass filter structure is proposed. By introducing a metallic via hole, the filter structure operates as one λ/2 and two λ/4 uniform impedance resonators and consequently form a triplet coupling scheme. The equivalent circuit model is analyzed in detail, which shows that there is a transmission zero in the low stopband. Based on that concept, three microstrip filters are designed, fabricated and measured, respectively. The first filter has no source/load coupling and only one transmission zero is created. By introducing source/load coupling, the second filter can create three transmission zeros. The third filter can create a controllable transmission zero in upper stopband. The simulated and measured results agree very well.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering (hsv//eng)

Publication and Content Type

ref (subject category)

art (subject category)