Abstract: We propose a new method to design crossovers by employing an embedded homogeneous cylindrical lens (HCL). Compared with traditional crossover designs, this strategy introduces an HCL within the air-filled substrate-integrated waveguide (SIW) crossover cavity to direct the incident waves in the desired direction. According to ray-tracing analysis, the added HCL can efficiently concentrate the electromagnetic wave propagating from the input to the output without increasing the fabrication complexity or footprint. The operating mechanism of this method is elaborated in detail, and is further verified by E-field distributions. Using the air-filled SIW technology, two-, three-, and four-channel crossovers operating at the millimeter-wave are developed and fabricated to demonstrate the practical feasibility of the proposed method. Some transitional structures are designed for experimental purposes. It is found that the simulated fractional bandwidths (FBWs) related to two-, three-, and four-channel air-filled SIW crossovers are 33%, 14%, and 10%, respectively; the dimensions of their core areas are 0.74λ×0.74λ, 1.43λ×1.43λ, and 1.90λ×1.90λ, respectively. Comparisons between our method and similar approaches in the literature illustrate the advantages of our method.

基于均匀柱面透镜的紧凑型毫米波空气填充基片集成波导交叉电桥

[1]Ali MMM, Sebak A, 2018. Compact printed ridge gap waveguide crossover for future 5G wireless communication system. IEEE Microw Wirel Compon Lett, 28(7):549-551.

[2]Bekefi G, Farnell GW, 1956. A homogeneous dielectric sphere as a microwave lens. Can J Phys, 34(8):790-803.

[3]Boriskin AV, Godi G, Sauleau R, et al., 2008. Small hemielliptic dielectric lens antenna analysis in 2-D: boundary integral equations versus geometrical and physical optics. IEEE Trans Antenn Propag, 56(2):485-492.

[4]Cheng XH, Liu ZY, Yao Y, et al., 2021. A wideband E-plane crossover coupler for terahertz applications. China Commun, 18(5):245-254.

[5]Chu PC, Tang CW, 2018. Design of a compact planar crossover with four intersecting channels. IEEE Microw Wirel Compon Lett, 28(4):293-295.

[6]Costa JR, Lima EB, Fernandes CA, 2009. Compact beam-steerable lens antenna for 60-GHz wireless communications. IEEE Trans Antenn Propag, 57(10):2926-2933.

[7]Djerafi T, Wu K, 2009. 60 GHz substrate integrated waveguide crossover structure. Proc European Microwave Conf, p.1014-1017.

[8]Doghri A, Djerafi T, Ghiotto A, et al., 2015. Substrate integrated waveguide directional couplers for compact three-dimensional integrated circuits. IEEE Trans Microw Theory Tech, 63(1):209-221.

[9]Feng WJ, Zhang TY, Che WQ, et al., 2016. Compact single-/dual-band planar crossovers based on strong coupled lines. IEEE Trans Compon Packag Manuf Technol, 6(6):854-863.

[10]Geng C, Lian JW, Ding DZ, 2022. Wideband millimeter-wave SIW two-channel crossover based on homogeneous cylindrical lens. IEEE 10^th Asia-Pacific Conf on Antennas and Propagation, p.1-2.

[11]Gunderson L, 1972. An electromagnetic analysis of a cylindrical homogeneous lens. IEEE Trans Antenn Propag, 20(4):476-479.

[12]Hesari SS, Bornemann J, 2017. Substrate integrated waveguide crossover formed by orthogonal TE₁₀₂ resonators. 47^th European Microwave Conf, p.17-20.

[13]Jiao LX, Wu YL, Zhuang Z, et al., 2018. A wideband uniplanar double-ring crossover with balanced and single-ended paths. IEEE Trans Microw Theory Tech, 66(12):5238-5247.

[14]Li YJ, Luk KM, 2016. A multibeam end-fire magnetoelectric dipole antenna array for millimeter-wave applications. IEEE Trans Antenn Propag, 64(7):2894-2904.

[15]Lian JW, Ban YL, Yang QL, et al., 2018. Planar millimeter-wave 2-D beam-scanning multibeam array antenna fed by compact SIW beam-forming network. IEEE Trans Antenn Propag, 66(3):1299-1310.

[16]Lian JW, Ban YL, Zhu JQ, et al., 2019. Planar 2-D scanning SIW multibeam array with low sidelobe level for millimeter-wave applications. IEEE Trans Antenn Propag, 67(7):4570-4578.

[17]Lian JW, Ban YL, Zhu H, et al., 2020. Uniplanar beam-forming network employing eight-port hybrid couplers and crossovers for 2-D multibeam array antennas. IEEE Trans Microw Theory Tech, 68(11):4706-4718.

[18]Lin JY, Wong SW, Wu YM, et al., 2019. Three-way multiple-mode cavity filtering crossover for narrowband and broadband applications. IEEE Trans Microw Theory Tech, 67(3):896-905.

[19]Niu ZQ, Zhang B, Li DT, et al., 2021. A mechanical reliability study of 3-dB waveguide hybrid couplers in submillimeter and terahertz bands. Front Inform Technol Electron Eng, 22(8):1104-1113.

[20]Parment F, Ghiotto A, Vuong TP, et al., 2015. Air-filled substrate integrated waveguide for low-loss and high power-handling millimeter-wave substrate integrated circuits. IEEE Trans Microw Theory Tech, 63(4):1228-1238.

[21]Qi ZH, Li XP, Zhu H, 2021. Low-cost high-order-mode cavity backed slot array antenna using empty substrate integrated waveguide for the 5G n260 band. Front Inform Technol Electron Eng, 22(4):609-614.

[22]Schoenlinner B, Wu XD, Ebling JP, et al., 2002. Wide-scan spherical-lens antennas for automotive radars. IEEE Trans Microw Theory Tech, 50(9):2166-2175.

[23]Sun L, Deng HW, Xue YF, et al., 2020. Compact-balanced BPF and filtering crossover with intrinsic common-mode suppression using single-layered SIW cavity. IEEE Microw Wirel Compon Lett, 30(2):144-147.

[24]Tajik A, Fakharzadeh M, Mehrany K, 2018. DC to 40-GHz compact single-layer crossover. IEEE Microw Wirel Compon Lett, 28(8):642-644.

[25]Tang CW, Chuang WM, 2015. Design of the planar six-port crossover with double rings. IEEE Microw Wirel Compon Lett, 25(10):651-653.

[26]Wu LS, Mao JF, 2016. A planar filtering crossover for three intersecting channels. IEEE MTT-S Int Microwave Symp, p.1-3.

[27]Wu LS, Guo YX, Mao JF, 2014. A planar microstrip crossover with lumped inductors for three intersecting channels. IEEE Trans Microw Theory Tech, 62(4):851-860.

[28]Xu HX, Wang GM, Chen PL, et al., 2011. Miniaturized fractal-shaped branch-line coupler for dual-band applications based on composite right/left handed transmission lines. J Zhejiang Univ-Sci C (Comput & Electron), 12(9):‍766-773.

[29]Yao JJ, Lee C, Yeo SP, 2011. Microstrip branch-line couplers for crossover application. IEEE Trans Microw Theory Tech, 59(1):87-92.

[30]Yu X, Sun S, 2019. Design of wideband lumped crossovers with resonator-loaded window shape structure. IEEE Microw Wirel Compon Lett, 29(5):309-311.

[31]Zhan WL, Xu JX, Zhao XL, et al., 2020. Substrate integrated waveguide multi-channel filtering crossover with extended channel number and controllable frequencies. IEEE Trans Circ Syst II Exp Briefs, 67(12):2858-2862.

[32]Zhang J, Wu W, Fang DG, 2011. 360° scanning multi-beam antenna based on homogeneous ellipsoidal lens fed by circular array. Electron Lett, 47(5):298-300.

[33]Zhou K, Wu K, 2020. Multi-channel SIW filtering crossover with flexibly specified frequencies and bandwidths. IEEE USNC-CNC-URSI North American Radio Science Meeting (Joint with AP-S Symp), p.117-118.