Abstract
| Original language | English |
|---|---|
| Pages (from-to) | 5036-5047 |
| Number of pages | 11 |
| Journal | IEEE Transactions on Antennas and Propagation |
| Volume | 61 |
| Issue number | 10 |
| DOIs | |
| Publication status | Published - 2013 |
| MoE publication type | A1 Journal article-refereed |
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Keywords
- antenna arrays
- millimeter-wave measurements
- near-field imaging
- reflectarray
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Reflectarray Design for 120-GHz Radar Application : Measurement Results. / Tamminen, A.; Mäkelä, S.; Ala-Laurinaho, J.; Häkli, Janne; Koivisto, Päivi; Rantakari, Pekka; Säily, Jussi; Luukanen, Arttu; Räisänen, A.V.
In: IEEE Transactions on Antennas and Propagation, Vol. 61, No. 10, 2013, p. 5036-5047.Research output: Contribution to journal › Article › Scientific › peer-review
TY - JOUR
T1 - Reflectarray Design for 120-GHz Radar Application
T2 - Measurement Results
AU - Tamminen, A.
AU - Mäkelä, S.
AU - Ala-Laurinaho, J.
AU - Häkli, Janne
AU - Koivisto, Päivi
AU - Rantakari, Pekka
AU - Säily, Jussi
AU - Luukanen, Arttu
AU - Räisänen, A.V.
PY - 2013
Y1 - 2013
N2 - In this paper, we present design and experimental results on reflectarrays at 120 GHz. The offset-fed reflectarrays consist of conductor-backed coplanar patch antennas with phase-shifting stubs. Three 138-mm reflectarrays are lithographically fabricated and evaluated in a near-field measurement range. Their measured beam patterns are compared to the theoretical ones. The theoretical -3-dB beam width is 60-64 mm at 3-m distance from the reflectarray. Measured beam widths of the different reflectarrays deviate less than 10% from the theoretical values. The beam pointing is found to be close to theoretical, whereas the sidelobe level is up to 5 dB higher. The efficiency, alignment accuracy, and surface shape of the reflectarray are studied with near-field imaging of the reflectarray aperture field. The measured average efficiency is 0.11 whereas the predicted average efficiency is 0.54. The low efficiency is most likely due to over-etching of the structures of the reflectarray element, and could be improved in future fabrication processing rounds. Beam pattern measurement close to the main beam is well suited for evaluating the beam width and pointing accuracy, but it gives little information on the element performance. We propose near-field imaging of the reflectarray to evaluate both element efficiency and phase shift.
AB - In this paper, we present design and experimental results on reflectarrays at 120 GHz. The offset-fed reflectarrays consist of conductor-backed coplanar patch antennas with phase-shifting stubs. Three 138-mm reflectarrays are lithographically fabricated and evaluated in a near-field measurement range. Their measured beam patterns are compared to the theoretical ones. The theoretical -3-dB beam width is 60-64 mm at 3-m distance from the reflectarray. Measured beam widths of the different reflectarrays deviate less than 10% from the theoretical values. The beam pointing is found to be close to theoretical, whereas the sidelobe level is up to 5 dB higher. The efficiency, alignment accuracy, and surface shape of the reflectarray are studied with near-field imaging of the reflectarray aperture field. The measured average efficiency is 0.11 whereas the predicted average efficiency is 0.54. The low efficiency is most likely due to over-etching of the structures of the reflectarray element, and could be improved in future fabrication processing rounds. Beam pattern measurement close to the main beam is well suited for evaluating the beam width and pointing accuracy, but it gives little information on the element performance. We propose near-field imaging of the reflectarray to evaluate both element efficiency and phase shift.
KW - antenna arrays
KW - millimeter-wave measurements
KW - near-field imaging
KW - reflectarray
U2 - 10.1109/TAP.2013.2273256
DO - 10.1109/TAP.2013.2273256
M3 - Article
VL - 61
SP - 5036
EP - 5047
JO - IEEE Transactions on Antennas and Propagation
JF - IEEE Transactions on Antennas and Propagation
SN - 0018-926X
IS - 10
ER -