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

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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

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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

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• LTCC technology has

been demonstrated to be very good platform for 60 GHz applications

• Consistent high-quality

processing accuracy of 50 μm conductor width and space with 10 % tolerance

• LTCC is mature

technology and can be regarded for millimetre wave module realisations

• Next challenge is to

expand the application field up to 100 GHz

Micrograph of a two-element 60 GHz microstrip line antenna 50 μm conductors

LTCC processing at VTT

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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.

LTCC Processing

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• 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

Millimetre wave antenna measurements

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Antenna design examples at 60 GHz

LTCC εr=5.99 z LTCC

patch radiator patch radiator microstrip line

LTCC εr=5.99 εr=1 air 50 52 54 56 58 60 62 64 66 68 70 Frequency (GHz)

Simulated input matching

• 30
• 25
• 20
• 15
• 10
• 5

Return loss (dB)

DB(|S(1,1)|) ACMPA DB(|S(1,1)|) ACMPA with cavity DB(|S(1,1)|) ACMPA with UC-PBG

ACMPA ACMPA with cavity ACMPA with UC-PBG

UC-PBG structure patch radiator

• 180
• 140
• 100
• 60
• 20

20 60 100 140 180 Theta (deg)

Simulated H-plane pattern

• 15
• 12
• 9
• 6
• 3

3 6 9 Gain (dB)

ACMPA ACMPA with cavity ACMPA with UC-PBG

3.1-3.5 dB gain improvement with a cavity or a UC-PBG structure

aperture microstrip line

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Optimised T-junctions for the antenna array feed networks

Improved input matching (and isolation) with the Wilkinson power divider

Reactive T-junction Wilkinson Zc=50 Ω Zc=70.7 Ω Zr=100Ω thin-film resistor co-fired on LTCC Zc= 50 Ω Zc= 35.36 Ω

Frequency (GHz) 50 52 54 56 58 60 62 64 66 68 70

• 50
• 45
• 40
• 35
• 30
• 25
• 20
• 15
• 10
• 5
• sim. S11
• sim. S22, S33
• meas. S11
• meas. S22
• meas. S33

|Smn| (dB) Frequency (GHz) 50 52 54 56 58 60 62 64 66 68 70

• 50
• 45
• 40
• 35
• 30
• 25
• 20
• 15
• 10
• 5
• sim. S11
• sim. S22, S33
• meas. S11
• meas. S22
• meas. S33

|Smn| (dB)

Reactive T-junction Wilkinson

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50 52 54 56 58 60 62 64 66 68 70 Frequency (GHz)

16 element Wilkinson feed network

• 60
• 50
• 40
• 30
• 20
• 10

S-parameter (dB)

59.96 GHz

• 21.76 dB

59.96 GHz

• 13.62 dB

DB(|S(17,17)|) Return loss DB(|S(17,11)|) Coupling DB(|S(17,12)|) Coupling DB(|S(11,12)|) Isolation DB(|S(11,11)|) Return loss DB(|S(12,12)|) Return loss

50 52 54 56 58 60 62 64 66 68 70 Frequency (GHz)

16 element reactive feed network

• 60
• 50
• 40
• 30
• 20
• 10

S-parameter (dB)

59.96 GHz

• 7.6329 dB

59.96 GHz

• 13.137 dB

DB(|S(17,17)|) Return loss DB(|S(17,11)|) Coupling DB(|S(17,12)|) Coupling DB(|S(11,12)|) Isolation DB(|S(11,11)|) Return loss DB(|S(12,12)|) Return loss

Feed networks for the 4x4 patch antenna arrays

port 17 3 mm port 11 port 12 9 mm port 11 port 12 3 mm port 17

Designed with Microwave Office, verified with Zeland IE3D

9 mm Ideal: -12.0 dB

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4x4 patch array 4x4 patch array with a cavity Losses of the feed network exluded from the results

• 3
• 6
• 90
• 1

2

• 1

5 180 1 5 1 2 90 6 3 Simulated gain at 60GHz Mag Max 20 dB Mag Min

• 20 dB

10 dB Per Div

Mag 15.31 dB Ang 0 dB

E-plane H-plane

• 3
• 6
• 90
• 1

2

• 1

5 180 1 5 1 2 90 6 3 Simulated gain at 60GHz Mag Max 20 dB Mag Min

• 20 dB

10 dB Per Div

Mag 18.5 dB Ang 0 dB

E-plane H-plane

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Wilkinson feed network 4x4 array H-plane measurement

Full-array simulations with IE3D Measured Gmax= 15.7 dBi

• 180 -140 -100
• 60
• 20

20 60 100 140 180

• 80
• 70
• 60
• 50
• 40
• 30
• 20
• 10

10 20 θ (°) Gain (dBi)

• sim. 60 GHz
• meas. 61 GHz

E-plane θ (°) Gain (dBi) H-plane

• sim. 60 GHz
• meas. 61 GHz
• 180 -140 -100
• 60
• 20

20 60 100 140 180

• 80
• 70
• 60
• 50
• 40
• 30
• 20
• 10

10 20

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4 element linear array for the phased array antenna demonstrator

Reactive power divider Microstrip feed MEMS phase shifters Equally-phased CPWs SCMPA elements AC bias pads (a,b) AC bias pads (c,d) Element spacing 0.65*λ0 = 3.25 mm @ 60 GHz 15 mm Flip-chip connections

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Recent publications on mm-wave antennas

• A. Lamminen, J. Säily, A. Vimpari, ”60 GHz patch antennas and arrays
• n 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

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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

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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