Highly selective wideband bandpass filter using combined microstrip/coplanar waveguide structure

Abstract

A highly selective wideband bandpass filter using a combined coplanar waveguide (CPW) and microstrip structure is proposed. The CPW section is responsible for creating a 4–8 GHz bandwidth. The microstrip split ring resonators and shorted coupled lines are used to sharpen the transitions between the passband and the stopband at lower and upper edges. The CPW section is fed by a microstrip host line and consists of two symmetrical coupled stepped‐impedance resonators to limit the bandwidth of the desired filter. A lumped element circuit model is presented and comparisons with experimental and simulation results confirm great compatibility and performance. The measurement results confirm a return loss larger than 15.3 dB in the passband, an out‐of‐band rejection greater than 15 dB.

A Compact CPW Bandpass Filter Based on Spiral-Shaped DGSS for 5g Frequency Band

“…The comparisons show that the proposed bandpass filter has a good performance. [4] 6.0 15.3 0.8 < 0.9 66% 3.6/8.9 0.64λ g × 0.46λ g [5] 3.5 24 1.7 < 2.0 8% 3.0/4.2 0.37λ g × 0.31λ g [6] 2.16 18 0.9 < 1.1 6.9% 1.5/3.1 0.19λ g × 0.65λ g [12] 2…”

“…CPW transmission line has a good dispersive property, and it can realize a broadband effect in circuits [4]. With the rapid development of 5G communication technology, communication systems not only need to improve the transmission rate but also require wider bandwidth than before, so CPW filter plays an essential role in the RF front-end.…”

Triple mode spiral wideband bandpass filter using symmetric dual‐line coupling

“…To accommodate WBPF's requirements such as flat passband, high selectivity and compact size several designs have been reported to reach reconciliation among the aforementioned features. A highly selective wideband bandpass filter using a combined coplanar waveguide and microstrip structure was proposed to achieve fractional bandwidth (FBW) of 66% [1]. However, this design relies on defected ground structure (DGS) technique.…”

“…Wideband bandpass filter (WBPF) is one of the most important components in such systems. Thus, many techniques have been reported to design WBPF with different topologies in several studies [1][2][3][4][5][6][7]. To accommodate WBPF's requirements such as flat passband, high selectivity and compact size several designs have been reported to reach reconciliation among the aforementioned features.…”

A compact conductor-backed CPW-based dual bandpass filter for satellite S-band and C-band

“…To achieve such high-frequency band, transition from microstrip to CPW technique will be the best choice to adopt [10,11]. Transition from microstrip to CPW without connecting wires is an emerging new technique to create more interest among researchers.…”