Reflectarray Design for 120-GHz Radar Application: Measurement Results

A. Tamminen, S. Mäkelä, J. Ala-Laurinaho, Janne Häkli, Päivi Koivisto, Pekka Rantakari, Jussi Säily, Arttu Luukanen, A.V. Räisänen

    Research output: Contribution to journalArticleScientificpeer-review

    9 Citations (Scopus)

    Abstract

    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.
    Original languageEnglish
    Pages (from-to)5036-5047
    Number of pages11
    JournalIEEE Transactions on Antennas and Propagation
    Volume61
    Issue number10
    DOIs
    Publication statusPublished - 2013
    MoE publication typeA1 Journal article-refereed

    Fingerprint

    Radar measurement
    Imaging techniques
    Antenna feeders
    Microstrip antennas
    Phase shift
    Etching
    Fabrication
    Processing

    Keywords

    • antenna arrays
    • millimeter-wave measurements
    • near-field imaging
    • reflectarray

    Cite this

    Tamminen, A., Mäkelä, S., Ala-Laurinaho, J., Häkli, J., Koivisto, P., Rantakari, P., ... Räisänen, A. V. (2013). Reflectarray Design for 120-GHz Radar Application: Measurement Results. IEEE Transactions on Antennas and Propagation, 61(10), 5036-5047. https://doi.org/10.1109/TAP.2013.2273256
    Tamminen, A. ; Mäkelä, S. ; Ala-Laurinaho, J. ; Häkli, Janne ; Koivisto, Päivi ; Rantakari, Pekka ; Säily, Jussi ; Luukanen, Arttu ; Räisänen, A.V. / Reflectarray Design for 120-GHz Radar Application : Measurement Results. In: IEEE Transactions on Antennas and Propagation. 2013 ; Vol. 61, No. 10. pp. 5036-5047.
    @article{56751295526a4636b0ed562947e15471,
    title = "Reflectarray Design for 120-GHz Radar Application: Measurement Results",
    abstract = "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.",
    keywords = "antenna arrays, millimeter-wave measurements, near-field imaging, reflectarray",
    author = "A. Tamminen and S. M{\"a}kel{\"a} and J. Ala-Laurinaho and Janne H{\"a}kli and P{\"a}ivi Koivisto and Pekka Rantakari and Jussi S{\"a}ily and Arttu Luukanen and A.V. R{\"a}is{\"a}nen",
    year = "2013",
    doi = "10.1109/TAP.2013.2273256",
    language = "English",
    volume = "61",
    pages = "5036--5047",
    journal = "IEEE Transactions on Antennas and Propagation",
    issn = "0018-926X",
    publisher = "IEEE Institute of Electrical and Electronic Engineers",
    number = "10",

    }

    Tamminen, A, Mäkelä, S, Ala-Laurinaho, J, Häkli, J, Koivisto, P, Rantakari, P, Säily, J, Luukanen, A & Räisänen, AV 2013, 'Reflectarray Design for 120-GHz Radar Application: Measurement Results', IEEE Transactions on Antennas and Propagation, vol. 61, no. 10, pp. 5036-5047. https://doi.org/10.1109/TAP.2013.2273256

    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 journalArticleScientificpeer-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 -