A compact planar diplexer based on via-free CRLH TL for WiMAX and WLAN applications

Abstract

In this paper, design and development of a via-free composite right/left handed transmission line (CRLH TL)-based diplexer for WiMAX and WLAN bands is reported. The diplexer is having two channels, where each channel consists of a separate bandpass filter (BPF). The BPF of both channels are designed on via-free CRLH TLs based on a newly proposed right-angled corner-modified split ring resonator (RAC-MSRR) structure. The RAC-MSRR incorporates meander paths because of which working scope of frequencies is focused for measured center frequencies (f1) 3.5 GHz with −3 dB fractional bandwidth (FBW) of 21.21% (BPF1 channel) and (f2) 5.6 GHz with −3 dB FBW of 13.29% (BPF2 channel). For diplexer design, T-section is used for joining two BPFs which results in very good isolation of more than 32.5 dB over the frequency band of 2.5–8.0 GHz. The designed diplexer has passband insertion loss of −0.87 dB at f1 and −1.25 dB at f2. Overall size of the fabricated diplexer including 50 Ω feed line is 18 × 15 mm2. Equivalent lumped circuit model parameters of the diplexer are obtained from the pseudo-inverse matrix technique. Measured results show good concurrence with simulated results and subsequently approve the proposed model design.

A Survey on microstrip filters, diplexers, and triplexers state of art between 2018 and 2022

“…The paper [10] proposed a diplexer has two channels, with a distinct bandpass filter for each channel (BPF). Using a novel suggested CMOS-based right-angled corner-modified split ring resonator (RAC-MSRR), the BPF of both channels is created on via-free CRLH TLs.…”

“…As the modern communication infrastructure evolves, reducing the size of microwave diplexers and improving their performance parameters has become an increasingly crucial and difficult problem [10]. Microstrip diplexers rely heavily on the branch length of the T or Y junction for impedance matching, as the frequency division diplexer is often made up of two passband filters.…”

A Compact Negative Group Delay Microstrip Diplexer with Low Losses for 5G Applications

“…Each of these techniques has its advantages and disadvantages and the selection of http://dx.doi.org/10.14500/aro.11237 technique depends on the particular requirements of the diplexer application. Folded open-loop ring resonators in (Feng, Zhang and Che, 2017), stub-loaded coupled U-shape cells in (Huang, et al, 2016), the meandrous and patch cells in (Rezaei and Noori, 2018), a transmission line that is composite right/left handed and free of vias in (Kumar and Upadhyay, 2019), and stub-loaded coupled open loops in are utilized to achieve microstrip diplexers. The patch and thin cells are combined in (Rezaei, Yahya and Jamaluddin, 2020) for designing a microstrip diplexer, which is suitable for GSM applications.…”

“…The reported diplexers in (Zhou, et al, 2018;Rezaei and Noori, 2020;Danaeian, 2020;Roshani and Roshani, 2019; have narrow channels. On the other hand, the common problem of the microstrip diplexers in (Feng, Zhang and Che, 2017;Huang, et al, 2016;Rezaei and Noori, 2018;Kumar and Upadhyay, 2019;Rezaei, Yahya and Jamaluddin, 2020;Zhou, et al, 2018;Rezaei and Noori, 2020;Danaeian, 2020;Roshani and Roshani, 2019; is their large implementation areas. Meanwhile, they could not improve group delay.…”