Design of Quad-Channel Diplexer and Tri-band Bandpass Filter Based on Multiple-Mode Stub-Loaded Resonators

Abstract

Multiple-mode stub-loaded resonator with quadchannel diplexer and tri-band bandpass filter are presented and analyzed theoretically in this paper. The multi-mode stub-loaded resonator employs the basic structure of a triplemode resonator. Herein, the triple-mode resonator is modified by introducing a mid-coupled line between the odd-mode resonances to produce a quad-mode resonator. The proposed resonator is applied in the quad-channel diplexer design, composing of two independent dual-band bandpass filters. In turn, the triple-band bandpass filter based on a parallel quadmode and a dual-mode stub-loaded resonator is developed. To validate the performance of the proposed resonators, two experimental examples, including a quad-channel diplexer and a triple-band bandpass filter are fabricated and measured. Each of the designed circuits occupies small area, i.e. about 0.32λ g ×0.22λ g and 0.18λ g ×0.20λ g respectively. Good agreements between simulated and measured results are achieved.

RF Channel-Selectivity Sensing by a Small Antenna of Metamaterial Channel Filters for 5G Sub-6-GHz Bands

“…Besides, the contributions of this work are mentioned in Table 2 where the differences of this work and the referenced works are compared. [8] × × × × × 0.16λ g × 0.16λ g [9] × × × × × 0.26λ g × 0.36λ g [10] × × × × × 0.23λ g × 0.12λ g [11] × × × × × 0.18λ g × 0.27λ g [12] × × × × × 0.108λ g × 0.521λ g [13] × × × × × 0.08λ g × 0.15λ g [14] × × × × × 0.44λ g × 0.39λ g [15] × × × × × 0.16λ g × 0.17λ g [17] × × × × × 0.18λ g × 0.20λ g [21] ×…”

“…Selectivity in the contiguous channel case can be realized as the following. Multiplexers like a duplexer and more channel elements are made up with filters and make the system effectively choose a channel [16][17][18]. One example of this kind is introduced in M. Chen et al's work where the conventional filters are assembled [16].…”

“…One example of this kind is introduced in M. Chen et al's work where the conventional filters are assembled [16]. Tantiviwat et al showed a multiplexer comprising stub-loaded MMRs as non-metamaterial filters and coupled port, one with two filters as parallel-edge coupling unlike the junction-type multiplexer [17]. Open-gapped SIR ring filters for effective size-reduction gathered to the common TX-line to implement a triplexer [18].…”

Dual-/Tri-Wideband Bandpass Filter with High Selectivity and Adjustable Passband for 5G Mid-Band Mobile Communications

“…Multi-mode resonator is one of the basic theories for multi-band BPFs. By combining two or more resonant modes of a multi-mode resonator, for instance, ring multi-mode resonators [5][6][7][8] and multi-mode stub-loaded resonators (SLRs) [9][10][11], the passband of the filter is formed. Combining more modes in one passband will increase the bandwidth [12].…”

“…Combining more modes in one passband will increase the bandwidth [12]. In Ref [10], a compact tri-band BPF is developed by multi-mode SLR, but with small bandwidth and large insertion loss. In addition, by utilizing the coupling between two multi-mode resonators, the odd-odd and even-even resonant modes contribute to the passbands, such as stepped-impedance resonators (SIRs) in tri-band BPFs [13] and dual-band BPFs [14,15], SLRs in tri-band BPFs [16,17], and dual-band BPFs [18][19][20].…”