Ridge Gap Waveguide Based Liquid Crystal Phase Shifter

In this paper, the gap waveguide technology is examined for packaging liquid crystal (LC) in tunable microwave devices. For this purpose, a line based passive phase shifter is designed and implemented in a ridge gap waveguide (RGW) topology and filled with LC serving as functional material. The inherent direct current (DC) decoupling property of gap waveguides is used to utilize the waveguide surroundings as biasing electrodes for tuning the LC. The bed of nails structure of the RGW exhibits an E-field suppression of 76 dB in simulation, forming a completely shielded device. The phase shifter shows a maximum figure of merit (FoM) of 70 °/dB from 20 GHz to 30 GHz with a differential phase shift of 387° at 25 GHz. The insertion loss ranges from 3.5 dB to 5.5 dB depending on the applied biasing voltage of 0 V to 60 V.

[1]  Qun Wu,et al.  Design of Filtering Tunable Liquid Crystal Phase Shifter Based on Spoof Surface Plasmon Polaritons in PCB Technology , 2019, IEEE Transactions on Components, Packaging and Manufacturing Technology.

[2]  P. Enoksson,et al.  Polymer based 140 GHz Planar Gap Waveguide Array Antenna for Line of Sight (LOS) MIMO Backhaul Links , 2019, 2019 IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications (IMWS-AMP).

[3]  Miguel Ferrando-Rocher,et al.  $8\times8\,\,Ka$ -Band Dual-Polarized Array Antenna Based on Gap Waveguide Technology , 2019, IEEE Transactions on Antennas and Propagation.

[4]  V. E. Boria-Esbert,et al.  Compact Combline Filter Embedded in a Bed of Nails , 2019, IEEE Transactions on Microwave Theory and Techniques.

[5]  Ahmed A. Kishk,et al.  $W$ -Band Low-Profile Monopulse Slot Array Antenna Based on Gap Waveguide Corporate-Feed Network , 2018, IEEE Transactions on Antennas and Propagation.

[6]  R. Ito,et al.  Basic Performance of Rectangular Waveguide Type Liquid Crystal Phase Shifter Driven by Magnetic Field , 2018, International Conference on Infrared, Millimeter, and Terahertz Waves.

[7]  Philippe Ferrari,et al.  $X$ -Band Reflection-Type Phase Shifters Using Coupled-Line Couplers on Single-Layer RF PCB , 2018, IEEE Microwave and Wireless Components Letters.

[8]  J. M. Pinheiro,et al.  Miniaturized Liquid Crystal Slow Wave Phase Shifter Based on Nanowire Filled Membranes , 2018, IEEE Microwave and Wireless Components Letters.

[9]  R. Reese,et al.  Interference based W-band single-pole double-throw with tunable liquid crystal based waveguide phase shifters , 2017, 2017 IEEE MTT-S International Microwave Symposium (IMS).

[10]  Jinfeng Li,et al.  High FoM liquid crystal based microstrip phase shifter for phased array antennas , 2016, 2016 International Symposium on Antennas and Propagation (ISAP).

[11]  D. Chu,et al.  Design of liquid crystal based coplanar waveguide tunable phase shifter with no floating electrodes for 60–90 GHz applications , 2016, 2016 46th European Microwave Conference (EuMC).

[12]  R. Jakoby,et al.  Continuously tuneable liquid crystal based stripline phase shifter realised in LTCC technology , 2015, 2015 10th European Microwave Integrated Circuits Conference (EuMIC).

[13]  Dariush Mirshekar-Syahkal,et al.  Beam steering 60 GHz slot antenna array using liquid crystal phase shifter , 2014, The 8th European Conference on Antennas and Propagation (EuCAP 2014).

[14]  Ralf Gehring,et al.  A light-weight tunable liquid crystal phase shifter for an efficient phased array antenna , 2013, 2013 European Microwave Conference.

[15]  R. Jakoby,et al.  Time-domain spectroscopy of novel nematic liquid crystals in the terahertz range , 2013, 2013 38th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz).

[16]  Chia-Chan Chang,et al.  A V-Band Three-State Phase Shifter in CMOS-MEMS Technology , 2013, IEEE Microwave and Wireless Components Letters.

[17]  F. Giacomozzi,et al.  Advanced characterization of a W-band phase shifter based on liquid crystals and MEMS technology , 2012, International Journal of Microwave and Wireless Technologies.

[18]  E. Rajo-Iglesias,et al.  New Microstrip Gap Waveguide on Mushroom-Type EBG for Packaging of Microwave Components , 2012, IEEE Microwave and Wireless Components Letters.

[19]  F. Fernández,et al.  Liquid crystal based phase shifters in 60 GHz band , 2010, The 3rd European Wireless Technology Conference.

[20]  Felix Gölden,et al.  Liquid Crystal Based Microwave Components with Fast Response Times: Material, Technology, Power Handling Capability , 2010 .

[21]  J. Zafar,et al.  Analog/Digital Ferrite Phase Shifter for Phased Array Antennas , 2010, IEEE Antennas and Wireless Propagation Letters.

[22]  F. Fernández,et al.  60 GHz Reflection Type Phase Shifter based on liquid crystal , 2010, 2010 IEEE Radio and Wireless Symposium (RWS).

[23]  R. Jakoby,et al.  Investigation of high performance transmission line phase shifters based on liquid crystal , 2009, 2009 European Microwave Conference (EuMC).

[24]  A. Gharbi,et al.  New tunable coplanar microwave phase shifter with nematic crystal liquid , 2008, 2008 3rd International Design and Test Workshop.

[25]  Gabriel M. Rebeiz,et al.  0.13-$\mu$m CMOS Phase Shifters for X-, Ku-, and K-Band Phased Arrays , 2007, IEEE Journal of Solid-State Circuits.

[26]  R. Jakoby,et al.  Tunable passive phase shifter for microwave applications using highly anisotropic liquid crystals , 2004, 2004 IEEE MTT-S International Microwave Symposium Digest (IEEE Cat. No.04CH37535).

[27]  Rolf Jakoby,et al.  Highly-anisotropic liquid-crystal mixtures for tunable microwave devices , 2003 .

[28]  Holger Maune,et al.  Liquid Crystal Based Dielectric Waveguide Phase Shifters for Phased Arrays at W-Band , 2019, IEEE Access.

[29]  Jian Yang,et al.  8 × 8 Ka-Band Dual-Polarized Array Antenna based on Gap Waveguide Technology , 2019 .

[30]  Alejandro Valero-Nogueira,et al.  Single-Layer Cavity-Backed Slot Array Fed by Groove Gap Waveguide , 2016, IEEE Antennas and Wireless Propagation Letters.

[31]  C. Christodoulou,et al.  Space Radiation Environment Testing of Liquid Crystal Phase Shifter Devices , 2016, IEEE Antennas and Wireless Propagation Letters.

[32]  E. Rajo-Iglesias,et al.  Local Metamaterial-Based Waveguides in Gaps Between Parallel Metal Plates , 2009, IEEE Antennas and Wireless Propagation Letters.

[33]  R. Jakoby,et al.  Passive Phase Shifter for W-Band Applications using Liquid Crystals , 2006, 2006 European Microwave Conference.

[34]  Akhlesh Lakhtakia,et al.  The physics of liquid crystals, 2nd edition: P.G. De Gennes and J. Prost, Published in 1993 by Oxford University Press, Oxford, UK, pp 7,597 + xvi, ISBN: 0-19-852024 , 1995 .