1 st IET Colloquium on Antennas, Wireless and Electromagnetics 29 May 2013, Loughborough University, Loughborough, UK Substrate Integrated Waveguide Technology for the Development of 60 GHz Photonic Transmitters Ivan Flammia, Besher Khani, Andreas Stöhr
Affiliation University of Duisburg-Essen Centre for Semiconductor Technology and Optoelectronics Lotharstr. 55 47057 Duisburg, Germany Email: ivan.flammia@uni-due.de
Introduction The 7 GHz bandwidth recently allocated worldwide in the 60 GHz band for unlicensed wireless communication has opened the possibility to a wide range of indoor and outdoor wireless gigabit-per-second applications [1]. In this scenario, the fiber-like wireless connectivity guaranteed by Radio-over-Fibre (RoF) technology plays a fundamental role in allowing the development of new high-data rate systems, without the need for complicated modulation formats [2]. In this work we discuss the development a 60 GHz photonic transmitter for indoor RoF applications, based on substrate integrated waveguide (SIW) technology implemented on highfrequency laminates.
Radio-over-Fibre (RoF) Potentially able to provide multi-gigabit data rates, allowing fibre-like wireless connectivity. Expansion of existing optical networks. Indoor/outdoor applications. Photonic transmitter: Fig. 1. Typical Radio-over-Fibre link. Operates the optical-to-electrical conversion by means of a highfrequency photodiode (PD) and transmits the RF signal via an opportune antenna.
60 GHz 57-64 GHz band (7 GHz of unlicensed spectrum bandwidth). Multi-gigabits data rate possible. Wireless PANs intended range: 10m. Replace various cables used today in office/home environment (gigabit Ethernet, USB, or IEEE 1394, HDMI). Increased mobility within the home. Fig. 2. Typical scenario of in-building Radio-over- Fibre [3]. Frequency reuse / security (attenuation of oxygen, walls) [4]. Several international standards for HD video streaming and file transfer (WirelessHD, ECMA-387, 802.15.3c, 802.11ad, WiGig) [5].
60 GHz Photonic Transmitter based on SIW Technology Integration approach: Use of RF laminates as integration platform for RoF applications: Successfully demonstrated [6]: E-Band photonic transmitter with offthe-shelf horn antenna. Integration of photodiode (wire bonds). Use of SIW technology: PD Chip (InP) Fig. 3. Interface between the highfrequency PD and the RF laminate. Wire bonds are used to connect the PD output to a grounded coplanar waveguide (GCPW) on the RF laminate. No need for external (horn) antennas (eliminates mounting steps, tolerances, enables higher frequency operation). Requires transition from GCPW-to-SIW and suitable antennas. G Wire bonds S G ROGERS 5880
Substrate Integrated Waveguide Promising candidate for the implementation of millimetre-wave integrated circuits [7, 8]. Cost-effective technology suitable for mass production. d p H W Fig. 4. Substrate integrated waveguide transmission line, with highlighted via holes parameters.
Substrate Integrated Waveguide Proper dimensioning is necessary to guarantee single mode operation: H d p W RF laminate: ROGERS 5880 Low-loss high-frequency substrate: ε r =2.2, tgδ = 0.0009. Fig. 5. Field propagation (60 GHz) in SIW on ROGERS 5880 laminate. Geometrical parameters: W = 2.9 mm, H = 0.38 mm, d = 0.2 mm, p = 0.4 mm, Z 0 ~ 75 Ω. α TE20 Single mode operation Fig. 6. Electric field distribution for the TE 10 (top) and TE 20 (bottom) modes. TE10 TE20 α TE10 β TE10 β TE20 Fig. 7. Propagation constant of the SIW depicted in Fig. 4.
GCPW-to-SIW Transition Requirements: Must allow biasing of the photodiode! DC block and RF choke: Use of coupled lines [9]: Constrains due to line/gap etching resolution (~100 µm): Z 0e = 187 Ω, Z 0o = 76 Ω. Z in =46 Ω, Z out = 78 Ω. Fig. 8. Layout of the transition. Fig. 10. 3D view of the transition. Fig. 9. S-parameters of the transition.
GCPW-to-SIW Transition Requirements: Must allow biasing of the photodiode! DC block and RF choke: Quarter-wave capacitive stubs + quarter-wave transformer. RF IN RF OUT DC Fig. 11. 3D view of the RF choke. Fig. 12. S-parameters of the RF choke.
GCPW-to-SIW Transition Allows correct biasing of the photodiode! DC block and RF isolation. In the 57-64 GHz band guarantees: Low loss (IL < 0.8 db), excellent matching (RL > 19 db) and excellent isolation (IS > 28 db ). Opens the possibility to the development of 60 GHz photonic transmitters based on SIW technology! Fig. 13. 3D view of the transition. Fig. 15. Integration concept for SIW photonic transmitter. Fig. 14. S-Parameters of the transition.
60 GHz Photonic Transmitter for Indoor Applications Indoor HD video streaming: Uncompressed HDMI wireless streaming (carrier: 60 GHz). Requires sector antenna to increase energy efficiency. Focus of the radiated power in a predefined user area. Possible candidate: SIW H-plane horn antenna! Fig. 16. Indoor distribution of uncompressed HD video signal. Note: the size of the photonic transmitter is in the order of a few centimetres; for visualization purposes, the antenna and the room are not represented in scale.
S11 (db) Gain (db) Dielectric-filled H-Plane Horn Antenna H-plane horn antenna on thin laminate (H = 381 um): Poor return loss (RL ~ 2 db). Poor front-to-back ratio (FTBR < 3 db). 0-2 10-0 E-Plane -5-10 -20-10 -30-40 H-Plane -15 50 55 60 65 70 Frequency (GHz) Fig. 17. Antenna model (left) and its RL (right). -50-200 -150-100 -50 0 50 100 150 200 Angle (degree) Fig. 18. Radiation pattern: 3D view (top) and rectangular plot (bottom).
S11 (db) Gain (db) SIW H-Plane Horn Antenna with Grating Transition Equivalent SIW H-plane horn antenna: Use of grating transition [10] to achieve satisfying matching (RL > 9 db) and high front-to-back ratio (FTBR > 23 db)! 0-3 10-0 E-Plane -5-10 -8-9 -10-20 -30 H-Plane -13-40 -15 50 53 55 58 60 63 65 68 70 Frequency (GHz) Fig. 19. Antenna model (left) and its RL (right). -50-200 -100 0 100 200 Angle (degree) Fig. 20. Radiation pattern: 3D view (top) and rectangular plot (bottom).
60 GHz Photonic Transmitter based on SIW Technology Integration platform: Use of laminate-based SIW for photonic transmitters! GCPW-to-SIW transition with planar bias tee. SIW sector antenna with engineered radiation pattern. Fig. 21. Integration concept for SIW photonic transmitter. ~ 2.5 cm Fig. 22. GCPW-to-SIW transition and SIW H-plane horn antenna.
Conclusions 60 GHz Radio-over-Fiber. Integration approach for novel photonic transmitter: Substrate Integrated Waveguide (SIW) technology Novel GCPW-to-SIW transition: Integrated fully planar bias tee (DC-block, RF choke). 0.8 db, RL > 15 db, IS > 28 db. 60 GHz photonic transmitter for indoor applications: SIW H-plane horn antenna. Sector antenna (improved efficiency). RL > 9 db, FTBR > 23 db.
Acknowledgements The University Duisburg-Essen acknowledges financial support by the European Commission and cooperation within the Marie Curie initial training network MITEPHO (grant agreement 238393).
References [1] S.-K. Yong, P. Xia and A. Valdes-Garcia, Introduction to 60GHz, in 60 GHz Technology for Gbps WLAN and WPAN: From Theory to Practice. John Wiley & Sons, Ltd, 2010. [2] A. Stöhr, S. Babiel, P. Cannard; C. Charbonnier, F. Van Dijk, S. Fedderwitz, et. al., Millimeter-wave photonic components for broadband wireless systems, in Microwave Theory and Techniques, IEEE Transactions on, vol. 58, pp. 3071-3082, 2010. [3] J. M- B. Oliveira et al.: Performance Assessment of UWB-Over-Fiber and Applications, in Ultra Wideband - Current Status and Future Trends InTech 2012. [4] Langen, B.; Lober, G.; Herzig, W., "Reflection and transmission behaviour of building materials at 60 GHz," Personal, Indoor and Mobile Radio Communications, 1994. Wireless Networks - Catching the Mobile Future., 5th IEEE International Symposium on, vol., no., pp.505,509 vol.2, 18-23 Sep 1994. [5] Singh, H.; Su-Khiong Yong; Jisung Oh; Chiu Ngo, "Principles of IEEE 802.15.3c: Multi-Gigabit Millimeter-Wave Wireless PAN," Computer Communications and Networks, 2009. ICCCN 2009. Proceedings of 18th International Conference on, vol., no., pp.1,6, 3-6 Aug. 2009. [6] I. Flammia, C.C. Leonhardt, J. Honecker, A.G. Steffan, A. Stöhr, Novel E-Band (71 76 GHz) photodiode module featuring a hermetic grounded-coplanar-waveguide-to-rectangularwaveguide transition, Microwave Photonics, 2011 International Topical Meeting on & Microwave Photonics Conference, 2011 Asia-Pacific, MWP/APMP, vol., no., pp.405-408, 18-21 Oct. 2011.
References [7] Bozzi, M.; Feng Xu; Deslandes, D.; Ke Wu, "Modeling and Design Considerations for Substrate Integrated Waveguide Circuits and Components," Telecommunications in Modern Satellite, Cable and Broadcasting Services, 2007. TELSIKS 2007. 8th International Conference on, vol., no., pp.p-vii,p-xvi, 26-28 Sept. 2007. [8] Ke Wu; Deslandes, D.; Cassivi, Y., "The substrate integrated circuits - a new concept for high-frequency electronics and optoelectronics," Telecommunications in Modern Satellite, Cable and Broadcasting Service, 2003. TELSIKS 2003. 6th International Conference on, vol.1, no., pp.p,iii-p-x vol.1, 1-3 Oct. 2003. [9] I. Flammia, B. Khani, A. Stöhr, A Novel Transition from Grounded Coplanar Waveguide to Substrate Integrated Waveguide for 60 GHz Radio-over-Fiber Photonic Transmitters, Microwave and Radio Electronics Week, Pardubice, Czech Republic, April 16-18, pp. 1-4, 2013. [10] Esquius-Morote, M.; Fuchs, B.; Mosig, J.R., "A new type of printed Ku-band SIW horn antenna with enhanced performances," Antennas and Propagation (ISAP), 2012 International Symposium on, vol., no., pp.223,226, Oct. 29 2012-Nov. 2 2012.