1. WEEKLY SEMINAR
Sunryul Kim

2. 12th European Conference on Antennas and Propagation (EuCAP 2018)
Paper Review I
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 5G Applications
12th European Conference on Antennas and Propagation (EuCAP 2018)
SUMMARY
GEOMETRY
FREQUENCY
28 GHz
STUCTURE
SIW fed slot Antenna
FEATURE
Compact
Low cost (FR308HR substrate)
High isolation (below -25 dB)
Wideband (3.685GHz, 13.1%)
Fig.1 Antenna geometry

3. SINGLE ANTENNA ELEMENT
Paper Review I
Paper Review II
SINGLE ANTENNA ELEMENT
ANTENNA ARRAY
DESIGN
CONSIDERATIONS
There are two design rules related to the pitch, via diameter and cut-off frequency.
(1)
(3)
(2)
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
“P” and “D” control the radiation loss and return loss.
“Ar” determine the cut-off frequency and propagation constant of the fundamental mode.
(4)
(5)
“a” is the broadside dimension of the air filled rectangular waveguide.

4. SINGLE ANTENNA ELEMENT
Paper Review I
Paper Review II
SINGLE ANTENNA ELEMENT
ANTENNA ARRAY
CONSIDERATIONS
FINAL DESIGN
The dimensions of the slot are in multiples of λ/4 and optimized for maximum matching.
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

5. SINGLE ANTENNA ELEMENT
Paper Review I
Paper Review II
SINGLE ANTENNA ELEMENT
ANTENNA ARRAY
S-PARAMETER
RADIATION PATTERN
4.7 dBi ?
26 GHz
29.56 GHz
Fig.3 Simulated and Measured S11 (dB) vs Frequency
Fig.4 Radiation pattern showing gain of the antenna
The proposed antenna is matched in a frequency range of 26 GHz to GHz.
The single element gain is 4.7 dBi.

6. SINGLE ANTENNA ELEMENT
Paper Review I
Paper Review II
SINGLE ANTENNA ELEMENT
ANTENNA ARRAY
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
An SIW fed slot antenna array of 5 elements is placed at 0.5λ inter-element spacing is shown in figure 5.
Maximum gain is 10 dBi and the half power beam width is 30˚.

7. SINGLE ANTENNA ELEMENT
Paper Review I
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.
The isolation in patch array is -16 dB for same inter-element spacing.
Without employing any decoupling techniques one can achieve sufficient isolation in an array using SIW.
The isolation between the array elements at 0.5λ inter-element spacing is below -25 dB both in simulations and measurements.

8. SINGLE ANTENNA ELEMENT
Paper Review I
Paper Review II
SINGLE ANTENNA ELEMENT
ANTENNA ARRAY
SCANNING
SCANNING PATTERN
In the case of patch antenna, the higher the beem steering angle, the lower the gain.
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
It can be observed that the main beam is exactly scanned to the required scan angle.
This is because of the high isolation of the antenna array.

9. Paper Review I Paper Review II
28/38-GHz Dual-Band Millimeter Wave SIW Array Antenna with EBG Structures for 5G Applications
2015 International Conference on Information and Communication Technology Research (ICTRC2015)
SUMMARY
GEOMETRY
FREQUENCY
28/38 GHz
STUCTURE
Slotted-SIW Antenna
SINGLE ANTENNA BANDWIDTH
0.45 GHz (1.6 %) at 28 GHz
2.20 GHz (5.8 %) at 38 GHz
SINGLE ANTENNA GAIN
5.2 dBi at 28 GHz
5.9 dBi at 38 GHz
ARRAY BANDWIDTH
0.32 GHz (1.14 %) at 28 GHz
1.9 GHz (5 %) at 38 GHz
ARRAY GAIN
11.9 dBi at 28 GHz
11.2 dBi at 38 GHz
Fig.10 Antenna geometry

10. SINGLE ANTENNA ELEMENT
Paper Review I
Paper Review II
SINGLE ANTENNA ELEMENT
ANTENNA ARRAY
DESIGN
S-PARAMETER
Fig.11 Slotted-SIW single antenna element front view
RT/duroid 5880 (εr = 2.2 , tanδ = 0.003)
Thickness : mm
Diameter of via holes : 0.50 mm
Via-to-via distance : 1 mm
Fig.12 Dual-band SIW single antenna element
reflection coefficient (S11).
The impedance bandwidth (S11 < -10dB) is 0.45 GHz (27.72 – GHz) and 2.20 GHz (36.70 – GHz) around 28 GHz and 38 GHz respectively.

11. SINGLE ANTENNA ELEMENT
Paper Review I
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)
The cross-pol levels are less than -25 dB in both planes.
The antenna exhibits good radiation characteristics in terms of back radiation and side lobe levels.
The maximum value of gain is found to be 5.2 dBi and 5.9 dBi at 28 GHz and 38 GHz, respectively.

12. SINGLE ANTENNA ELEMENT
Paper Review I
Paper Review II
SINGLE ANTENNA ELEMENT
ANTENNA ARRAY
ARRAY
S-PARAMETER
Fig.15 Dual-band 1 × 4 slotted SIW antenna array.
Distance between the adjacent radiating elements is around λg (guided wavelength at 28 GHz).
The array is fed by 1 × 4 Wilkinson power divider surrounded by electromagnetic bandgap (EBG) structures.
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 (S11).
The impedance bandwidth (S11 < -10 dB) of 0.32 GHz (27.95 GHz – GHz) and 1.90 GHz (37.29 GHz – GHz) is achieved around 28 GHz and 38 GHz respectively.

13. SINGLE ANTENNA ELEMENT
Paper Review I
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.
At 28 GHz, the array of slot 1 is radiating at its maximum level.
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.

14. SINGLE ANTENNA ELEMENT
Paper Review I
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)
The gain values at the respective frequency bands are 11.9 dBi and 11.2 dBi, respectively.

15. IDEA 28GHz 5G 단말용 배열안테나 목표 Magneto-electric dipole Self-Complementary
인체 둔감성
격리도 향상
빔 조향 성능 향상
빔 폭 확장
Magneto-electric dipole
광대역 특성
인체에 의한 공진주파수 이동에 내성을 가짐
후방방사 상쇄
인체영향을 줄일 수 있을 것으로 예상
Substrate Integrated Waveguide
높은 격리도
빔 조향 성능 향상
Fractal
Self-Complementary
광대역 특성
인체에 의한 공진주파수 이동에 내성을 가짐
Magnetic half
Wire 안테나에 비해 efficiency, gain, human-body power loss 특성이 좋음
Slot
Magnetic
Efficiency, gain, human-body power loss 특성이 좋음
Circular polarization
목표에 부합하는 장점은 찾지 못하였음

16. IDEA SIW fed slot antenna SIW fed magneto-electric dipole
Upper side : Magnetic dipole
Lower side : Magnetic loop

17. THANK YOU