Wideband Microstrip-to-Microstrip Vialess Vertical Transition Based on Multilayer Liquid Crystal Polymer Technology

doi:10.1007/s12204-023-2621-z

Abstract

Abstract: A Ka-band wideband microstrip-to-microstrip (MS-to-MS) vialess vertical transition on slotline multimode resonator (MMR) is presented. The proposed transition mainly consists of a slotline MMR on the common ground plane, and two microstrip (MS) lines facing each other at the top and third layers in the four-layered liquid crystal polymer (LCP) substrate. In order to improve the bandwidth of the proposed transition, a U-shaped branch is added to the top- and third-layer MS lines, separately. The slotline MMR can be properly excited by setting the position of the U-shaped branch line. As such, a three-pole wideband vertical transition is obtained, which shows a good transmission performance over a wide frequency range of 29.27—39.95 GHz. The three-pole wideband vertical transition based on multilayer LCP substrate is designed, fabricated, and measured. Test results indicate that a wide frequency range of 26.84—36.26 GHz can be obtained with return loss better than −10 dB and insertion loss less than −3dB.

Key words: wideband, microstrip-to-microstrip (MS-to-MS), vialess vertical transition, slotline multi-mode resonator (MMR)

摘要：

本文提出了一种Ka波段宽带微带到微带槽线多模谐振器的无孔垂直过渡结构。在4层LCP电路中，所提出的过渡结构主要包括在公共地平面上的槽线谐振器，以及顶层和第3层彼此相对的两条微带线。为了改善所提出过渡结构的带宽，在顶层和第3层微带线上分别添加了U型枝节线。通过调节U型枝节线的位置，可以适当地激发槽线谐振器。因此，获得了一个三极点宽频垂直过渡结构，在29.27—39.9 5 GHz宽频范围内显示出良好的传输性能。基于多层LCP衬底设计了三极点宽带垂直过渡结构，并进行了制作和测试。测试结果表明，可以得到在26.84—36.26 GHz的宽频率范围内，回波损耗优于-10 dB，插入损耗小于-3 dB。

关键词: 宽带，微带到微带，无孔垂直过度结构，槽线谐振器

CLC Number:

TN45

LIU Weihong , GUAN Dongyang , HUANG Qian , CHEN Liuyang, ZHANG Menglin . Wideband Microstrip-to-Microstrip Vialess Vertical Transition Based on Multilayer Liquid Crystal Polymer Technology[J]. J Shanghai Jiaotong Univ Sci, 2025, 30(2): 220-226.

References

[1] VALOIS R, BAILLARGEAT D, VERDEYME S, et al. High performances of shielded LTCC vertical transitions from DC up to 50GHz [J]. IEEE Transactions on Microwave Theory and Techniques, 2005, 53(6): 2026- 2032.

[2] CASARES-MIRANDA F P, VIERECK C, CAMACHO-PENALOSA C, et al. Vertical microstrip transition for multilayer microwave circuits with decoupled passive and active layers [J]. IEEE Microwave and Wireless Components Letters, 2006, 16(7): 401-403.

[3] LI E S, CHENG J C, LAI C C. Designs for broadband microstrip vertical transitions using cavity couplers [J]. IEEE Transactions on Microwave Theory and Techniques, 2006, 54(1): 464-472.

[4] POZAR D M. Analysis and design of cavity-coupled microstrip couplers and transitions [J]. IEEE Transactions on Microwave Theory and Techniques, 2003, 51(3): 1034-1044.

[5] CHEN C, TSAI M J, ALEXOPOULOS N G. Optimization of aperture transitions for multi-port microstrip circuits [C]//1996 IEEE MTT-S International Microwave Symposium Digest. San Francisco: IEEE, 1996: 711-714.

[6] ZHU L,WU K. Ultrabroad-band vertical transition for multilayer integrated circuits [J]. IEEE Microwave and Guided Wave Letters, 1999, 9(11): 453-455.

[7] ABBOSH A M. Vertical microstrip-microstrip transition for ultra wideband applications [C]//2007 Asia- Pacific Microwave Conference. Bangkok: IEEE, 2007: 1-4.

[8] TAOZW, SUNJ F, HUANGM, et al. Design of wideband slot-coupled microstrip vertical transition [J]. International Journal of RF and Microwave Computer- Aided Engineering, 2020, 30(4): e22118.

[9] YANG L, ZHU L, CHOI W W, et al. Compact wideband microstrip-to-microstrip vertical transition with extended upper stopband [J]. International Journal of RF and Microwave Computer-Aided Engineering, 2018, 28(4): e21228.

[10] HU K Y, JIANG Y, FENG L P, et al. A wideband filtering microstrip-to-microstrip vialess vertical transition on CPW MMR [J]. International Journal of RF and Microwave Computer-Aided Engineering, 2021, 31(4): e22567.

[11] ZHANG Y F, SHI S Y, MARTIN R D, et al. Ultrawideband vialess microstrip line-to-stripline transition in multilayer LCP substrate for E- and W-band applications [J]. IEEE Microwave and Wireless Components Letters, 2017, 27(12): 1101-1103.

[12] SERCU J, FACHE N, LIBBRECHT F, et al. Mixed potential integral equation technique for hybrid microstrip-slotline multilayered circuits using a mixed rectangular-triangular mesh [J]. IEEE Transactions on Microwave Theory and Techniques, 1995, 43(5): 1162- 1172.

[13] HUANG X B, WU K L. A broadband and vialess vertical microstrip-to-microstrip transition [J]. IEEE Transactions on Microwave Theory and Techniques, 2012, 60(4): 938-944.

[14] ZHU L, SUN S, MENZEL W. Ultra-wideband (UWB) bandpass filters using multiple-mode resonator [J]. IEEE Microwave and Wireless Components Letters, 2005, 15(11): 796-798.

[15] GUO X, ZHU L, WANG J P, et al. Wideband microstrip-to-microstrip vertical transitions via multiresonant modes in a slotline resonator [J]. IEEE Transactions on Microwave Theory and Techniques, 2015, 63(6): 1902-1909.

[16] YANG L, ZHU L, CHOI W W, et al. Analysis and design of wideband microstrip-to-microstrip equal ripple vertical transitions and their application to bandpass filters [J]. IEEE Transactions on Microwave Theory and Techniques, 2017, 65(8): 2866-2877.