Bandwidth enhancement for thin substrate UHF RFID patch antenna
Article Category: research-article
Publié en ligne: 02 mai 2019
Pages: 1 - 8
Reçu: 22 déc. 2018
© 2019 Prabakar Parthiban published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Figure. 1
Antenna designs and fabrications (dimensions are in mm): (a) Matched patch antenna design (b) −64% Intentional input mismatch, (c) −32% Intentional input mismatch (d) +32% Intentional input mismatch.Figure. 2
Return loss |S11| (top) and path loss |S21| (bottom) measurements.Figure. 3
Radiation pattern of −32% mismatched patch antenna.Figure. 4
−32% mismatched patch with wood, glass and plastic assets.Figure. 5
Frequency sensitivity on matched vs −32% mismatched antenna.Measured return loss, path loss and gain.
|
|
Low Freq. |
Mid Freq. |
High Freq. |
Antenna type |
Measured loss |
Flow (MHz) |
Loss (dB) |
Fc (MHz) |
Loss (dB) |
Fhigh (MHz) |
Loss (dB) |
Matched antenna |
Return loss |
877.1 |
−5.04 |
915.0 |
−26.1 |
954.2 |
−5.08 |
|
Path loss |
857.32 |
−27.4 |
915.0 |
−23.7 |
951.93 |
−27.4 |
|
Gain (dBi) |
857.32 |
2.08 |
915.0 |
5.71 |
951.93 |
2.10 |
−64% Ω mismatch |
Return loss |
901.7 |
−4.95 |
928.7 |
−5.93 |
960.7 |
−5.03 |
|
Path loss |
901.73 |
−26.9 |
928.7 |
−26.8 |
960.71 |
−27.2 |
|
Gain (dBi) |
901.73 |
2.59 |
928.7 |
2.66 |
960.71 |
2.22 |
−32% Ω mismatch |
Return loss |
870.8 |
−5.06 |
915.0 |
−14.2 |
959.7 |
−5.05 |
|
Path loss |
849.58 |
−27.4 |
915.0 |
−24.4 |
955.92 |
−27.4 |
|
Gain (dBi) |
2.01 |
915.0 |
5.01 |
955.92 |
2.06 |
2.01 |
+32% Ω mismatch |
Return loss |
893.2 |
−5.07 |
918.0 |
−32.3 |
942.87 |
−5.04 |
|
Path loss |
893.27 |
−25.3 |
918.0 |
−24.3 |
942.8 |
−25.9 |
|
Gain (dBi) |
4.18 |
918.0 |
5.17 |
942.8 |
3.55 |
4.18 |
Measured Azimuth and Elevation radiation pattern.
|
Azimuth Beam-width |
Elevation beam-width |
Antenna type |
Flow
|
Fc
|
Fhigh
|
Flow
|
Fc
|
Fhigh
|
−32% mismatch |
83° |
87° |
89° |
85° |
90° |
87° |
Measured RSSI for various assets.
Reader output |
Frequency (MHz) |
902 |
915 |
928 |
902 |
915 |
928 |
902 |
915 |
928 |
902 |
915 |
928 |
10 dBm |
Material |
Free space |
Wood |
Plastic |
Glass |
|
RSSI (dB) |
−51 |
−52 |
−49 |
−67 |
−68 |
−69 |
−82 |
−84 |
−85 |
−86 |
−84 |
−84 |
−20 dBm |
Material |
Free space |
Wood |
Plastic |
Glass |
|
RSSI (dB) |
−54 |
−52 |
−49 |
−69 |
−68 |
−68 |
−79 |
−79 |
−80 |
−82 |
−83 |
−83 |
30 dBm |
Material |
Free space |
Wood |
Plastic |
Glass |
|
RSSI (dB) |
−50 |
−48 |
−47 |
−67 |
−68 |
−70 |
−83 |
−84 |
−82 |
−83 |
−82 |
−84 |