Coplanar Waveguide Gap Research Articles

A Wide-Stopband Bandpass Filter Using < λ /16 Capacitive-Coupled Short-Circuited Resonators in Wide-Gap Coplanar Waveguide Structure

A compact bandpass filter (BPF) using a very short capacitively coupled resonator exhibits wide-stopband characteristics. It is based on two <λ/16 short-circuited resonators built on a coplanar waveguide (CPW) having unusually wide gap. The filter's input/output ports are connected to the resonator through microstrip-to-CPW broadside-coupled transition structure. The proposed filter is simple and compact without employing any additional structural elements that are often used in conventional approaches. It is found that the stopband characteristic can be significantly extended only by properly setting the coupling capacitance of the broadside coupling structure, the length of the resonator, and the CPW gap. A second-order BPF with a center frequency (f0) of 2.45 GHz and a 3-dB bandwidth of 10.6% is fabricated on a liquid crystal polymer substrate, demonstrating dramatically extended stopband suppression of 30 dB up to 9.8f0. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1752–1755, 2013

The influence of metallization thickness on the characteristics of cascaded junction discontinuities of shielded coplanar type transmission line

A full-wave analysis based on the mode-matching technique is applied to analyze cascaded junction discontinuities of coplanar-type transmission lines, coplanar waveguide (CPW) and finline. Results for a CPW-finline transition, a shielded CPW gap and a symmetric notch incorporating the finite metallization thickness effect are presented. The influence of metallization thickness on the coupling effect exhibited by cascaded junction discontinuities is also presented and discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>