WEEKLY SEMINAR Sunryul Kim 2019 01 30 117

WEEKLY SEMINAR Sunryul Kim 2019. 01. 30 1/17 Antennas & RF Devices Lab.

Paper Review II A Compact Low Cost High Isolation Substrate Integrated Waveguide Fed Slot Antenna Array at 28 GHz employing Beamforming and Beam Scanning for 5 G Applications 12 th European Conference on Antennas and Propagation (Eu. CAP 2018) SUMMARY GEOMETRY ü FREQUENCY Ø 28 GHz ü STUCTURE Ø SIW fed slot Antenna ü FEATURE Ø Compact Ø Low cost (FR 308 HR substrate) Ø High isolation (below -25 d. B) Ø Wideband (3. 685 GHz, 13. 1%) Fig. 1 Antenna geometry 2/17 Antennas & RF Devices Lab.

Paper Review II SINGLE ANTENNA ELEMENT ANTENNA ARRAY DESIGN CONSIDERATIONS ü There are two design rules related to the pitch, via diameter and cut-off frequency. (1) (3) (2) ü The equivalent SIW width “Ae” is the width of rectangular waveguide whose modes exhibit the same propagation characteristics of the SIW modes. Fig. 2 SIW Slot Antenna ü “P” and “D” control the radiation loss and return loss. (4) ü “Ar” determine the cut-off frequency and propagation constant of the fundamental mode. (5) ü “a” is the broadside dimension of the air filled rectangular waveguide. 3/17 Antennas & RF Devices Lab.

Paper Review II SINGLE ANTENNA ELEMENT ANTENNA ARRAY CONSIDERATIONS FINAL DESIGN ü The dimensions of the slot are in multiples of λ/4 and optimized for maximum matching. ü The position of the slot is kept at electrical maxima (3λ/4) in the SIW for maximum coupling. Fig. 2 SIW Slot Antenna Fig. 2 Realized prototype of proposed antenna 4/17 Antennas & RF Devices Lab.

Paper Review II SINGLE ANTENNA ELEMENT ANTENNA ARRAY S-PARAMETER RADIATION PATTERN 4. 7 d. Bi ? 26 GHz 29. 56 GHz Fig. 3 Simulated and Measured S 11 (d. B) vs Frequency Fig. 4 Radiation pattern showing gain of the antenna ü The proposed antenna is matched in a frequency range of 26 GHz to 29. 56 GHz. ü The single element gain is 4. 7 d. Bi. 5/17 Antennas & RF Devices Lab.

Paper Review II SINGLE ANTENNA ELEMENT ANTENNA ARRAY DESIGN RADIATION PATTERN Fig. 5 5 SIW fed Slot Antenna Array elements placed at 0. 5 λ excited simultaneously Fig. 6 Combined Radiation Pattern (Beam forming) at 0. 5 λ inter element spacing ü An SIW fed slot antenna array of 5 elements is placed at 0. 5λ inter-element spacing is shown in figure 5. ü Maximum gain is 10 d. Bi and the half power beam width is 30˚. 6/17 Antennas & RF Devices Lab.

Paper Review II SINGLE ANTENNA ELEMENT ANTENNA ARRAY ISOLATION COMPARISON Fig. 8 Isolation in a 5 -element patch array for 0. 5λ inter-element spacing Fig. 7 High isolation between radiating elements at 0. 5λ inter-element spacing. ü The isolation in patch array is -16 d. B for same inter-element spacing. ü The isolation between the array elements at 0. 5λ inter-element spacing is below -25 d. B both in simulations and measurements. ü Without employing any decoupling techniques one can achieve sufficient isolation in an array using SIW. 7/17 Antennas & RF Devices Lab.

Paper Review II SINGLE ANTENNA ELEMENT ANTENNA ARRAY SCANNING PATTERN ü In the case of patch antenna, the higher the beem steering angle, the lower the gain. ü It also produces an error while scanning to a specific angle, that is, if scan angle is 60˚ it might only scan to 45˚ or 50˚ depending upon the isolation. Fig. 9 60˚ Beam Scanning ü It can be observed that the main beam is exactly scanned to the required scan angle. ü This is because of the high isolation of the antenna array. 8/17 Antennas & RF Devices Lab.

Paper Review II 28/38 -GHz Dual-Band Millimeter Wave SIW Array Antenna with EBG Structures for 5 G Applications 2015 International Conference on Information and Communication Technology Research (ICTRC 2015) SUMMARY GEOMETRY ü FREQUENCY Ø 28/38 GHz ü STUCTURE Ø Slotted-SIW Antenna ü SINGLE ANTENNA BANDWIDTH Ø 0. 45 GHz (1. 6 %) at 28 GHz Ø 2. 20 GHz (5. 8 %) at 38 GHz ü SINGLE ANTENNA GAIN Ø 5. 2 d. Bi at 28 GHz Ø 5. 9 d. Bi at 38 GHz ü ARRAY BANDWIDTH Ø 0. 32 GHz (1. 14 %) at 28 GHz Ø 1. 9 GHz (5 %) at 38 GHz ü ARRAY GAIN Ø 11. 9 d. Bi at 28 GHz Ø 11. 2 d. Bi at 38 GHz Fig. 10 Antenna geometry 9/17 Antennas & RF Devices Lab.

Paper Review II SINGLE ANTENNA ELEMENT ANTENNA ARRAY DESIGN S-PARAMETER Fig. 11 Slotted-SIW single antenna element front view ü ü RT/duroid 5880 (εr = 2. 2 , tanδ = 0. 003) Thickness : 0. 254 mm Diameter of via holes : 0. 50 mm Via-to-via distance : 1 mm Fig. 12 Dual-band SIW single antenna element reflection coefficient (S 11). ü The impedance bandwidth (S 11 < -10 d. B) is 0. 45 GHz (27. 72 – 28. 17 GHz) and 2. 20 GHz (36. 70 – 38. 90 GHz) around 28 GHz and 38 GHz respectively. 10/17 Antennas & RF Devices Lab.

Paper Review II SINGLE ANTENNA ELEMENT ANTENNA ARRAY RADIATION PATTERN Fig. 13 E-plane radiation pattern at 28 GHz, 38 GHz (single element) Fig. 14 H-plane radiation pattern at 28 GHz, 38 GHz (single element) ü The cross-pol levels are less than -25 d. B in both planes. ü The antenna exhibits good radiation characteristics in terms of back radiation and side lobe levels. ü The maximum value of gain is found to be 5. 2 d. Bi and 5. 9 d. Bi at 28 GHz and 38 GHz, respectively. 11/17 Antennas & RF Devices Lab.

Paper Review II SINGLE ANTENNA ELEMENT ANTENNA ARRAY S-PARAMETER Fig. 15 Dual-band 1 × 4 slotted SIW antenna array. ü Distance between the adjacent radiating elements is around λg (guided wavelength at 28 GHz). ü The array is fed by 1 × 4 Wilkinson power divider surrounded by electromagnetic bandgap (EBG) structures. ü To improve the array radiation characteristics, a ground structure based on a compact uniplanar EBG unit cell has been used. Fig. 16 Dual-band 1 × 4 slotted SIW antenna array reflection coefficient (S 11). ü The impedance bandwidth (S 11 < -10 d. B) of 0. 32 GHz (27. 95 GHz – 28. 27 GHz) and 1. 90 GHz (37. 29 GHz – 39. 19 GHz) is achieved around 28 GHz and 38 GHz respectively. 12/17 Antennas & RF Devices Lab.

Paper Review II SINGLE ANTENNA ELEMENT ANTENNA ARRAY E-FIELD DISTRIBUTION (a) (b Fig. 17 Simulated electric field distribution at (a) 28 GHz. (b)) 38 GHz. ü At 28 GHz, the array of slot 1 is radiating at its maximum level. ü Similarly, the wave propagation inside the SIW cavity structure at 38 GHz is not disturbed by the array of slot 1 and eventually it is radiated through the array of slot 2. 13/17 Antennas & RF Devices Lab.

Paper Review II SINGLE ANTENNA ELEMENT ANTENNA ARRAY RADIATION PATTERN Fig. 18 E-Plane radiation pattern at 28 GHz, 38 GHz (1× 4 Array) Fig. 19 H-Plane radiation pattern at 28 GHz, 38 GHz (1× 4 Array) ü The gain values at the respective frequency bands are 11. 9 d. Bi and 11. 2 d. Bi, respectively. 14/17 Antennas & RF Devices Lab.

IDEA ü SIW fed slot antenna ü SIW fed magneto-electric dipole Upper side : Magnetic dipole Lower side : Magnetic loop 16/17 Antennas & RF Devices Lab.

THANK YOU 17/17 Antennas & RF Devices Lab.