Design and Processing of Millimetre Wave Antennas on Low-temperature - PowerPoint PPT Presentation

Design and Processing of Millimetre Wave Antennas on Low-temperature Co-fired Ceramic (LTCC) Substrates Jussi Säily Antti Lamminen Antti Vimpari Ismo Huhtinen Jouko Aurinsalo COST IC0603, April 9th – 11th 2008

VTT TECHNICAL RESEARCH CENTRE OF FINLAND OUTLINE • Introduction • LTCC processing at VTT • Millimetre wave antenna measurements • Antenna design examples at 60 GHz • Recent publications on mm-wave antennas • National and international cooperation • Conclusions 2

VTT TECHNICAL RESEARCH CENTRE OF FINLAND Introduction • VTT and its partners are developing key technologies for low cost millimetre wave radio systems with data rates of several gigabits per second • High level of transceiver integration on CMOS and LTCC • 60 GHz frequency band for short-range communications • 71-76 GHz and 81-86 GHz frequency bands for outdoor applications • Applications: WLAN, WPAN, WMAN, wireless backhaul for cellular networks, last mile solutions, intelligent transport management systems (ITMS) MIMO system model with time-varying multipath radio channel 3

VTT TECHNICAL RESEARCH CENTRE OF FINLAND LTCC processing at VTT • LTCC technology has 50 μ m conductors been demonstrated to be very good platform for 60 GHz applications • Consistent high-quality processing accuracy of 50 μ m conductor width and space with 10 % tolerance • LTCC is mature technology and can be regarded for millimetre wave module realisations • Next challenge is to Micrograph of a two-element expand the application 60 GHz microstrip line antenna field up to 100 GHz 4

VTT TECHNICAL RESEARCH CENTRE OF FINLAND LTCC Processing LTCC process: a) glass/ceramic LTCC tape material, b) tape blanking, c) via punching, d) via metallization, e) conductor printing (or photoimaging), f) layer alignment and stacking, g) lamination, h) sintering, i) dicing of fired panel, j) component and die attach. 5

VTT TECHNICAL RESEARCH CENTRE OF FINLAND Millimetre wave antenna measurements • S-parameter measurements with an Agilent probe station • DC to 110 GHz in a single sweep • Radiation patterns measurements in an anechoic chamber • Spectrum analyser is used as receiver 6

VTT TECHNICAL RESEARCH CENTRE OF FINLAND Antenna design examples at 60 GHz ACMPA Simulated input matching z 0 patch radiator -5 microstrip line Return loss (dB) -10 LTCC ε r =5.99 DB(|S(1,1)|) ACMPA -15 DB(|S(1,1)|) ACMPA with cavity -20 DB(|S(1,1)|) LTCC patch radiator ACMPA with UC-PBG -25 aperture ε r =5.99 LTCC -30 ACMPA with ε r =1 50 52 54 56 58 60 62 64 66 68 70 air microstrip line cavity Frequency (GHz) Simulated H-plane pattern 9 ACMPA 6 ACMPA with cavity ACMPA with UC-PBG ACMPA with UC-PBG 3 0 Gain (dB) -3 UC-PBG structure -6 patch radiator -9 -12 -15 -180 -140 -100 -60 -20 20 60 100 140 180 3.1-3.5 dB gain improvement with a cavity or a UC-PBG structure Theta (deg) 7

VTT TECHNICAL RESEARCH CENTRE OF FINLAND Optimised T-junctions for the antenna array feed networks Z r =100 Ω thin-film resistor co-fired on LTCC Reactive T-junction Wilkinson Z c = 35.36 Ω Z c =70.7 Ω Z c =50 Ω Z c = 50 Ω Reactive T-junction Wilkinson 0 0 -5 -5 -10 -10 -15 -15 |S mn | (dB) |S mn | (dB) -20 -20 -25 -25 -30 -30 -35 -35 sim. S 11 meas. S 11 sim. S 11 meas. S 11 -40 -40 sim. S 22 , S 33 meas. S 22 sim. S 22 , S 33 meas. S 22 meas. S 33 meas. S 33 -45 -45 -50 -50 50 52 54 56 58 60 62 64 66 68 70 50 52 54 56 58 60 62 64 66 68 70 Frequency (GHz) Frequency (GHz) Improved input matching (and isolation) with the Wilkinson power divider 8

VTT TECHNICAL RESEARCH CENTRE OF FINLAND Feed networks for the 4x4 patch antenna arrays port 11 port 11 3 mm 3 mm port 12 port 12 9 mm 9 mm port 17 port 17 Ideal: -12.0 dB 16 element reactive feed network 16 element Wilkinson feed network 0 0 59.96 GHz -13.62 dB -10 -10 59.96 GHz -21.76 dB 59.96 GHz S-parameter (dB) -7.6329 dB S-parameter (dB) -20 -20 DB(|S(17,17)|) 59.96 GHz Return loss -13.137 dB DB(|S(17,17)|) DB(|S(17,11)|) -30 -30 Return loss Coupling DB(|S(17,11)|) DB(|S(17,12)|) Coupling Coupling DB(|S(17,12)|) -40 -40 DB(|S(11,12)|) Coupling Isolation DB(|S(11,12)|) Isolation DB(|S(11,11)|) Return loss DB(|S(11,11)|) -50 -50 Return loss DB(|S(12,12)|) DB(|S(12,12)|) Return loss Return loss -60 -60 50 52 54 56 58 60 62 64 66 68 70 50 52 54 56 58 60 62 64 66 68 70 Frequency (GHz) Frequency (GHz) Designed with Microwave Office, verified with Zeland IE3D 9

VTT TECHNICAL RESEARCH CENTRE OF FINLAND 4x4 patch array Simulated gain at 60GHz Mag Max 0 0 20 dB Mag 15.31 dB 3 - 3 Ang 0 dB 0 0 6 - 6 0 E-plane H-plane 90 -90 1 2 0 0 2 1 - 1 0 5 5 0 1 10 dB Mag Min - 180 Per Div -20 dB 4x4 patch array with a cavity Simulated gain at 60GHz Mag Max 0 20 dB 0 Mag 18.5 dB 3 - Ang 0 dB 3 0 0 6 - 6 0 E-plane H-plane 90 -90 1 2 0 0 2 1 - 1 0 5 5 0 1 10 dB Mag Min 180 - Per Div -20 dB Losses of the feed network exluded from the results 10

VTT TECHNICAL RESEARCH CENTRE OF FINLAND 4x4 array Wilkinson feed network H-plane measurement Full-array simulations with IE3D Measured G max = 15.7 dBi 20 20 E -plane H -plane sim. 60 GHz sim. 60 GHz 10 10 meas. 61 GHz meas. 61 GHz 0 0 Gain (dBi) -10 -10 Gain (dBi) -20 -20 -30 -30 -40 -40 -50 -50 -60 -60 -70 -70 -80 -80 -180 -140 -100 -60 -20 20 60 100 140 180 -180 -140 -100 -60 -20 20 60 100 140 180 θ (°) θ (°) 11

VTT TECHNICAL RESEARCH CENTRE OF FINLAND 4 element linear array for the phased array antenna demonstrator SCMPA elements Equally-phased CPWs AC bias pads (a,b) MEMS phase shifters Reactive power divider Microstrip feed Element spacing 0.65* λ 0 = 3.25 mm @ 60 GHz 15 mm AC bias pads (c,d) Flip-chip connections 12

VTT TECHNICAL RESEARCH CENTRE OF FINLAND Recent publications on mm-wave antennas • A. Lamminen, J. Säily, A. Vimpari, ”60 GHz patch antennas and arrays on LTCC with embedded-cavity substrates”, IEEE Transactions on Antennas and Propagation , accepted for publication • A. Vimpari, A. Lamminen, J. Säily, “Design and measurements of 60 GHz probe-fed patch antennas on low temperature co-fired ceramic substrates”, Proceedings of the European Microwave Week 2006 • A. Lamminen, J. Säily, A. Vimpari, “Design and processing of 60 GHz antennas on low-temperature co-fired ceramics (LTCC) substrate”, Proceedings of 4th ESA Workshop on Millimetre Wave Technology and Applications, 2006 13

VTT TECHNICAL RESEARCH CENTRE OF FINLAND National and international cooperation • VTT Technical Research Centre of Finland • Circuits and Antennas (Espoo) • Communication Platforms (Oulu) • Micromodules (Oulu) • Helsinki University of Technology (TKK) • CMOS : Electronic Circuit Design Laboratory (ECDL) • Si-integrated antennas, propagation : Radio Laboratory • International cooperation partners • CMOS : Berkeley Wireless Research Center (BWRC), USA • CMOS : STMicroelectronics, France • Lens antennas : University of Rennes, France • Si-integrated antennas : University of Nice, France 14

VTT TECHNICAL RESEARCH CENTRE OF FINLAND Conclusions • The LTCC process at VTT is proven suitable for mm-wave antennas with its minimum linewidths of 50 microns +/- 10% • Ferro A6-S material system characterisation was done for 50– 75 GHz using ring resonators • Measured antennas and feed networks at 65 GHz • Accuracy should be good enough for high-performance antennas at E-band (77 GHz) • Many antenna structures have been designed and tested • Aperture-coupled, CPW-slot coupled, proximity-coupled, probe-fed antennas • EBG structures and embedded cavities can be used to reduce array mutual coupling and increase efficiency 15