A planar balanced‐to‐balanced filtering power divider with in‐band common‐mode suppressions and self‐isolation

Abstract

A compact balanced‐to‐balanced (BTB) filtering power divider (FPD) with in‐band common‐mode (CM) suppressions based in a single‐layer substrate‐integrated waveguide (SIW) is presented in this article. This FPD mainly consists of one full‐mode and two half‐mode SIW cavities where each cavity's differential‐mode (DM) and CM are designed reasonably. The filtering DM signals to dual‐ports power division is realized with a simple and compact configuration. Moreover, the CM signals can be naturally rejected without any additional isolation circuits. Ultimately, the BTB FPD with a center frequency of 10.5 GHz is designed, fabricated, and measured to verify the proposed design concept, which shows below −15 dB 6% DM filtering fractional bandwidth (FBW). The CM transmission is suppressed below −22 dB over 28.6% FBW. The proposed design exhibits the advantages of compact size, simple design, low loss, planarity, and multi‐function fusion.

Broadband Balanced-to-Balanced Filtering Power Divider Using HMSIW-SSPP Transmission Line

“…The proposed BTB FPD's DM isolation between output ports approaches the BTB FPDs in [8,9], but within a broader range. This design features a better IL than that of BTB FPDs in [2][3][4][5][6][7][8][9]. Table 3 shows the performance of the proposed BTB FPD and other reported BTB FPDs.…”

“…Although the SSPP BTB FPD in [5] achieves a 152% FBW and compactness, this proposed design has better IL, RL, and isolation than that of [5]. The proposed BTB FPD's DM isolation between output ports approaches the BTB FPDs in [8,9], but within a broader range. This design features a better IL than that of BTB FPDs in [2][3][4][5][6][7][8][9].…”

“…Table 3 shows the performance of the proposed BTB FPD and other reported BTB FPDs. The proposed BTB FPD based on the HMSIW-SSPP transmission line has a broader operating bandwidth than the BTB FPDs in [ 2 , 3 , 4 , 6 , 7 , 8 , 9 ], and it also possesses independent control of the passband’s lower and upper cut-off frequencies, making obtaining the desired frequency response easier. Although the SSPP BTB FPD in [ 5 ] achieves a 152% FBW and compactness, this proposed design has better IL, RL, and isolation than that of [ 5 ].…”

“…The substrate-integrated waveguide (SIW) boasts high power capacity and easy integration with planar circuits. Several BTB FPDs based on SIW/half-mode SIW (HMSIW) resonators are documented in [ 6 , 7 , 8 , 9 ]. Ref.…”

“…Additionally, Ref. [ 9 ] suggested a compact single-layer BTB FPD by integrating one full-mode SIW cavity resonating at TE 210 mode and two HMSIW cavities resonating at TE 120 modes. Single-layer and dual-layer dual-band SIW BTB FPD with high performance are proposed in [ 10 , 11 ].…”