**Electromagnetic simulations and design of 77 GHz antenna in LTCC technology. **

*Fig.1. Cross section of a LTCC structure with isolation ring (lay 14), metallisations (in yellow on lay 6), small cavity on lay 3. *

*Fig.2. Cross section of a LTCC structure*

**Antena microstrip patch (MPA)**

*Fig.3. Cross section of a antenna structure in LTCC technology*

*Fig.4. 77 GHz Optimised antenna layout *

*Fig.5. Simulations result for77 GHz antenna gain*

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*Fig 6. Lay-out of the 2x2 antennas array*

*Fig.7.Simulations results for Reflexive losses of 2x2 antennas array*

*Fig.8 Simulations results for the gain of 2x2 antennas array*

*Fig.9. 3-D image of 2 vertical connections through SL-stripline*

*Fig.10. Simulations results of S parametres for vertical connections through SL-stripline*

*Fig.11. 3D image of two CPW-SIW transitions connected by SIW*

*Fig.12.S parameters- Simulations results for two CPW-SIW transitions*

*Fig.13. E-field distribution for two CPW-SIW transitions*

*Fig. 14. Measurements and simulations resuts for S parameters of CPW_SL_CPW*

**Design and optimisation for a 77 GHz receiver in LTCC technology**

The receiver module is based on flip-cip Schottky diode on GaAs DMK 2790 Skyworks Solutions Inc., with the characteristics: RS = 4 W, CT=0.05 pF (capacitance Cp = 0.02 pF), ideality factor n = 1.05, saturation current IS = 0.5 pA.

*Fig.15. 3D image of receiver structure (antenna area) *

*Fig.15. 3D image of receiver structure (Schottky diode area)*

*Fig 17. 3D simulation for pattern radiation of 77 GHz antenna*

*Fig.18. Photo image of receiver structure (antenna contacts area) in LTCC technology*

*Fig.19. Measurements of detected voltage at diode contacts versus frequency (DC current is 45 **μA) *

*Fig.20. Simulations results for detected voltage at diode contacts versus frequency* *(DC current is 45 μA)*

*Fig.21. Radiation pattern in 2D measured at 77 GHz (triangles –plane H)*

*Fig.22. Optimised antenna element for 77 GHz*

*Fig. 23. S11 parameter (reflexion losses) for the 77 GHz Optimised antenna element*

*Fig.24. Radiation pattern for the optimised antenna element*

*Fig.25. 2x1 antennas array for 77 GHz*

*Fig.26.* *reflexion losses for 77GHz 2x1 antennas array *

*Fig.27*. * Radiation pattern for2x1 antennas array at 77 GHz*

*Fig.28. Wide band directivity of main radiation direction of 2x1 antennas array*

*Fig.29. Image of structures in LTCC technology*

*Fig.30. Experimental set-up of “on wafer” measurements for 77GHz antennas structures*

**2x1 antennas array module optimised at 77GHz – experimental results**

“on wafer” measurements for 77GHz antennas structures are presented in fig 31 . One can observes a good agreement with the simulations results as well as better performances for the band width, extended to 74-88 GHz

*Fig.31. Experimental results in comparaison with simulations results*

*Fig.32. S21 measurements for the 2x1 antenna array and the antenna element*