Author Contributions
Conceptualization, J.Y., E.A. and H.R.; methodology, J.Y., H.R., M.E.N. and A.A. (Ahmed Amir); software, J.Y., E.A., M.E.N., A.A. (Ahmed Amir), A.A. (Amir Altaf) and M.E.; validation, J.Y., E.A. and S.S.A.; formal analysis, J.Y., E.A., M.E.N., A.A. (Ahmed Amir), A.A. (Amir Altaf), M.E. and S.S.A.; investigation, J.Y., E.A., M.E.N. and A.A. (Ahmed Amir); resources, J.Y. and H.R.; data curation, J.Y., E.A., M.E.N., A.A. (Ahmed Amir), A.A. (Amir Altaf) and M.E.; writing—original draft preparation, J.Y., M.E.N., A.A. (Ahmed Amir) and A.A. (Amir Altaf); writing—review and editing, J.Y., E.A., A.A. (Amir Altaf), M.E., S.S.A. and H.R.; visualization, J.Y., E.A., A.A. (Ahmed Amir), A.A. (Amir Altaf) and M.E.; supervision, J.Y. and H.R.; funding acquisition, J.Y. and H.R. All authors have read and agreed to the published version of the manuscript.
Figure 1.
Design of Arabic letter ب (baa) tag: (a) Tag dimensions; (b) Structure of the tag.
Figure 1.
Design of Arabic letter ب (baa) tag: (a) Tag dimensions; (b) Structure of the tag.
Figure 2.
Operation principle of designed chipless Arabic alphabet tags.
Figure 2.
Operation principle of designed chipless Arabic alphabet tags.
Figure 3.
Realized tags and simulation setup: (a) All designed Arabic letter tags with Arial font size of 28 mm; (b) Tag simulation analysis setup in CST MWS using FDTD method.
Figure 3.
Realized tags and simulation setup: (a) All designed Arabic letter tags with Arial font size of 28 mm; (b) Tag simulation analysis setup in CST MWS using FDTD method.
Figure 4.
Current distribution of selective designed Arabic tags at their resonance frequencies: (a) letter ب; (b) letter د; (c) letter ر; (d) letter و; (e) letter ه.
Figure 4.
Current distribution of selective designed Arabic tags at their resonance frequencies: (a) letter ب; (b) letter د; (c) letter ر; (d) letter و; (e) letter ه.
Figure 5.
RCS results of Arabic letter tags (أ, ب, ت, ث, ج, ح, خ, د, ذ, ر, ز, س, ش, ص, ض) with Arial font type and font size of 28.
Figure 5.
RCS results of Arabic letter tags (أ, ب, ت, ث, ج, ح, خ, د, ذ, ر, ز, س, ش, ص, ض) with Arial font type and font size of 28.
Figure 6.
RCS results of Arabic letter tags (ط, ظ, ع, غ, ف, ق, ك, ل, م, ن, ه, و, ي) with Arial font type and font size of 28.
Figure 6.
RCS results of Arabic letter tags (ط, ظ, ع, غ, ف, ق, ك, ل, م, ن, ه, و, ي) with Arial font type and font size of 28.
Figure 7.
Numerical model of realized letter haa (ه) model using MoM technique (a) without mesh; (b) with mesh.
Figure 7.
Numerical model of realized letter haa (ه) model using MoM technique (a) without mesh; (b) with mesh.
Figure 8.
Comparison of RCS characteristics of letters ب and ه using FDTD and MoM techniques.
Figure 8.
Comparison of RCS characteristics of letters ب and ه using FDTD and MoM techniques.
Figure 9.
Designed letter د tag with various fonts with the same size of 28: (a) Arial; (b) Calibri; (c) Times New Roman (TNR).
Figure 9.
Designed letter د tag with various fonts with the same size of 28: (a) Arial; (b) Calibri; (c) Times New Roman (TNR).
Figure 10.
Comparison of RCS results of alphabet د tag with various font types (Arial, Calibri, and Times New Roman) with font size of 28: (a) Vertical polarization; (b) Horizontal polarization.
Figure 10.
Comparison of RCS results of alphabet د tag with various font types (Arial, Calibri, and Times New Roman) with font size of 28: (a) Vertical polarization; (b) Horizontal polarization.
Figure 11.
Designed letter ر tag with various fonts with the same size of 28: (a) Arial; (b) Calibri; (c) Times New Roman (TNR).
Figure 11.
Designed letter ر tag with various fonts with the same size of 28: (a) Arial; (b) Calibri; (c) Times New Roman (TNR).
Figure 12.
Comparison of RCS results of alphabet ر tag with various font types (Arial, Calibri, and Times New Roman) with the font size of 28: (a) Vertical polarization; (b) Horizontal polarization.
Figure 12.
Comparison of RCS results of alphabet ر tag with various font types (Arial, Calibri, and Times New Roman) with the font size of 28: (a) Vertical polarization; (b) Horizontal polarization.
Figure 13.
Designed letter ه tag with various fonts with the same size of 28: (a) Arial; (b) Calibri; (c) Times New Roman (TNR).
Figure 13.
Designed letter ه tag with various fonts with the same size of 28: (a) Arial; (b) Calibri; (c) Times New Roman (TNR).
Figure 14.
Comparison of RCS results of alphabet ه tag with various font types (Arial, Calibri, and Times New Roman) with the font size of 28: (a) Vertical polarization; (b) Horizontal polarization.
Figure 14.
Comparison of RCS results of alphabet ه tag with various font types (Arial, Calibri, and Times New Roman) with the font size of 28: (a) Vertical polarization; (b) Horizontal polarization.
Figure 15.
Designed letter و tag with various fonts with the same size of 28: (a) Arial; (b) Calibri; (c) Times New Roman (TNR).
Figure 15.
Designed letter و tag with various fonts with the same size of 28: (a) Arial; (b) Calibri; (c) Times New Roman (TNR).
Figure 16.
Comparison of RCS results of alphabet و tag with various font types (Arial, Calibri, and Times New Roman) with the font size of 28: (a) Vertical polarization; (b) Horizontal polarization.
Figure 16.
Comparison of RCS results of alphabet و tag with various font types (Arial, Calibri, and Times New Roman) with the font size of 28: (a) Vertical polarization; (b) Horizontal polarization.
Figure 17.
Designed letters and comparison of RCS results of alphabet د tag for vertical polarization with various font types and sizes: (a) Designed letter د tag with various fonts and sizes; (b) RCS results of Arial font with 28, 20, and 16 sizes; (c) RCS results of Calibri font with 28, 20, and 16 sizes; and (d) RCS results of Times New Roman (TNR) font with 28, 20, and 16 sizes.
Figure 17.
Designed letters and comparison of RCS results of alphabet د tag for vertical polarization with various font types and sizes: (a) Designed letter د tag with various fonts and sizes; (b) RCS results of Arial font with 28, 20, and 16 sizes; (c) RCS results of Calibri font with 28, 20, and 16 sizes; and (d) RCS results of Times New Roman (TNR) font with 28, 20, and 16 sizes.
Figure 18.
Designed letters and comparison of RCS results of alphabet ر tag for vertical polarization with various font types and sizes: (a) Designed letter ر tag with various fonts and sizes; (b) RCS results of Arial font with 28, 20, and 16 sizes; (c) RCS results of Calibri font with 28, 20, and 16 sizes; and (d) RCS results of Times New Roman (TNR) font with 28, 20, and 16 sizes.
Figure 18.
Designed letters and comparison of RCS results of alphabet ر tag for vertical polarization with various font types and sizes: (a) Designed letter ر tag with various fonts and sizes; (b) RCS results of Arial font with 28, 20, and 16 sizes; (c) RCS results of Calibri font with 28, 20, and 16 sizes; and (d) RCS results of Times New Roman (TNR) font with 28, 20, and 16 sizes.
Figure 19.
Designed letter and comparison of RCS results of alphabet ه tag for vertical polarization with various font types and sizes: (a) Designed letter ه tag with various fonts and sizes; (b) Arial font with 28, 20, and 16 sizes; (c) Calibri font with 28, 20, and 16 sizes; and (d) Times New Roman (TNR) font with 28, 20, and 16 sizes.
Figure 19.
Designed letter and comparison of RCS results of alphabet ه tag for vertical polarization with various font types and sizes: (a) Designed letter ه tag with various fonts and sizes; (b) Arial font with 28, 20, and 16 sizes; (c) Calibri font with 28, 20, and 16 sizes; and (d) Times New Roman (TNR) font with 28, 20, and 16 sizes.
Figure 20.
Designed letters and comparison of RCS results of alphabet و tag for vertical polarization with various font types and sizes: (d) Design letter و tag with different fonts and sizes; (b) Arial font with 28, 20, and 16 sizes; (c) Calibri font with 28, 20, and 16 sizes; and (d) Times New Roman (TNR) font with 28, 20, and 16 sizes.
Figure 20.
Designed letters and comparison of RCS results of alphabet و tag for vertical polarization with various font types and sizes: (d) Design letter و tag with different fonts and sizes; (b) Arial font with 28, 20, and 16 sizes; (c) Calibri font with 28, 20, and 16 sizes; and (d) Times New Roman (TNR) font with 28, 20, and 16 sizes.
Table 1.
Co- and cross-polar resonate frequencies of designed Arabic tag IDs with Arial font type of size 28 (waveforms in
Figure 5 and
Figure 6).
Table 1.
Co- and cross-polar resonate frequencies of designed Arabic tag IDs with Arial font type of size 28 (waveforms in
Figure 5 and
Figure 6).
Tag | Vertical Polarization | Horizontal Polarization |
---|
Letter أ | 4.816–9.37 | ――- |
Letter ب | 2.738–4.982–6.918–9.085–11.527 | 2.705–11.538 |
Letter ت | 2.694–5.015–6.962–9.096–11.571 | 2.705–11.56 |
Letter ث | 2.694–5.004–6.962–9.14–11.637 | 2.705–11.615 |
Letter ج | 4.839–6.291–7.281–9.701–11.395 | 4.85–6.28–7.27 |
Letter ح | 4.861–6.313–7.303–9.745–11.439 | 4.872–6.302–7.292 |
Letter خ | 1.748–4.883–6.313–7.292–9.745–11.439 | 4.784–4.883–6.313–7.2841 |
Letter د | 3.629–7.93–11.604 | 7.919 |
Letter ذ | 3.662–7.941–11.692 | 7.919 |
Letter ر | 3.442–6.61 | 3.442–6.61 |
Letter ز | 3.453–6.654 | 3.453–6.654 |
Letter س | 4.157–4.905–6.984–7.435–9.855–10.867 | 4.905–7.435–9.844 |
Letter ش | 2.023–4.168–4.905–6.984–7.424–9.866–10.801 | 4.905–7.413–9.855 |
Letter ص | 1.671–3.519–4.795–6.159– 6.423–7.303–9.514–10.779 | 3.508–6.434–7.314 |
Letter ض | 1.682–3.508–4.795–6.17–6.412–7.303–9.514–10.812–11.296 | 3.497–6.412–7.314 |
Letter ط | 2.364–4.08–6.093–6.445–7.193–8.513–11.208–11.835 | 3.981–4.08 |
Letter ظ | 2.375–4.08–6.093–7.193–8.502–11.219–11.835 | 3.981–4.091 |
Letter ع | 1.88–3.585–5.169–6.885–8.612–10.449–11.813 | 5.169–6.874–8.601 |
Letter غ | 1.88–3.64–5.158–6.896–8.623–10.482–11.868 | 5.158–6.896–8.601 |
Letter ف | 2.331–4.828–6.918–8.535–11.824 | 10.592–11.813 |
Letter ق | 2.1–4.256–6.566–8.953–10.207–11.197 | 4.256–6.566–11.197 |
Letter ك | 2.166–4.102–5.246–6.511– 8.172–8.81–10.317 | 4.102 |
Letter ل | 2.012–4.014–5.763–7.534–9.69–11.538 | 4.014–7.523 |
Letter م | 3.53–6.478–8.81 | 8.799 |
Letter ن | 2.76–4.795–7.039–9.701 | 2.76–7.028 |
Letter ه | 7.754–10.108 | 10.119 |
Letter و | 3.475–7.6–10.482 | 7.589 |
Letter ي | 1.99–3.739–5.312–7.193–9.382–11.01 | 3.75–7.182–9.338–10.999 |
Table 2.
Signature resonance frequencies for letter د tag with various font types (Arial, Calibri, and Times New Roman) with the font size of 28.
Table 2.
Signature resonance frequencies for letter د tag with various font types (Arial, Calibri, and Times New Roman) with the font size of 28.
Tag د | Vertical Polarization | Horizontal Polarization |
---|
Arial | 3.629–7.93–11.604 | 3.629–7.93 |
Calibri | 3.046–6.566–9.613 | 3.046–6.566 |
TNR | 3.376–7.523 | 3.376–7.523 |
Table 3.
Signature resonance frequencies for letter ر tag with various font types (Arial, Calibri, and Times New Roman) with the font size of 28.
Table 3.
Signature resonance frequencies for letter ر tag with various font types (Arial, Calibri, and Times New Roman) with the font size of 28.
Tag ر | Vertical Polarization
| Horizontal Polarization |
---|
Arial | 3.442–6.61 | 3.442–6.61 |
Calibri | 3.134–6.489 | 3.134–6.489 |
TNR | 3.244–6.247 | 3.244–6.247 |
Table 4.
Signature resonance frequencies for tag letter ه with various font types (Arial, Calibri and Times New Roman) with the font size of 28.
Table 4.
Signature resonance frequencies for tag letter ه with various font types (Arial, Calibri and Times New Roman) with the font size of 28.
Tag ه | Vertical Polarization
| Horizontal Polarization |
---|
Arial | 7.754–10.108 | 10.108 |
Calibri | 3.629–5.136–6.852–9.041 | 3.629–5.136–6.852–9.041–11.252 |
TNR | 7.171–9.679 | 9.679 |
Table 5.
Signature resonance frequencies for letter و tag with various font types (Arial, Calibri, and Times New Roman) with the font size of 28.
Table 5.
Signature resonance frequencies for letter و tag with various font types (Arial, Calibri, and Times New Roman) with the font size of 28.
Tag و | Vertical Polarization | Horizontal Polarization
|
---|
Arial | 3.475–7.6–10.482 | 3.475–7.6 |
Calibri | 2.507–6.126–7.534–8.568–10.834 | 6.126–7.534–8.568–10.834 |
TNR | 3.255–7.193–9.789–11.846 | 3.255–7.193–11.846 |
Table 6.
Change in resonance frequency (Δf) in % in vertical polarization for analyzed tags for changing font types with reference to Arial font type.
Table 6.
Change in resonance frequency (Δf) in % in vertical polarization for analyzed tags for changing font types with reference to Arial font type.
Font Type | Δf (%) |
---|
| Tag د | Tag ر | Tag ه | Tag و |
Calibri | −16.1 | −8.9 | −53.2 | −27.9 |
TNR | −7.0 | −6.3 | −7.5 | −6.3 |
Table 7.
Signature resonance frequencies for letter tag د with various font types and sizes (* represents resonant frequency out of analyzed frequency range).
Table 7.
Signature resonance frequencies for letter tag د with various font types and sizes (* represents resonant frequency out of analyzed frequency range).
| Vertical Polarization | Horizontal Polarization |
---|
Arial-28 | 3.629–7.93 | 7.93 |
Arial-20 | 5.059–10.79 | 10.79 |
Arial-16 | 6.28–* | — |
Calibri-28 | 3.046–6.566–9.613 | 6.566 |
Calibri-20 | 4.278–9.096–* | 9.096 |
Calibri-16 | 5.422–11.23–* | 11.23 |
TNR-28 | 3.376–7.523 | 7.523 |
TNR-20 | 4.85–10.295 | 10.295 |
TNR-16 | 5.994–* | — |
Table 8.
Signature resonance frequencies for letter tag ر with various font types and sizes.
Table 8.
Signature resonance frequencies for letter tag ر with various font types and sizes.
| Vertical Polarization | Horizontal Polarization |
---|
Arial-28 | 3.442–6.61 | 3.442–6.61 |
Arial-20 | 4.762–9.162 | 4.762–9.162 |
Arial-16 | 5.917–11.406 | 5.917–11.406 |
Calibri-28 | 3.134–6.489 | 3.134–6.489 |
Calibri-20 | 4.339–9.063 | 4.339–9.063 |
Calibri-16 | 5.466–11.175 | 5.466–11.175 |
TNR-28 | 3.244–6.247 | 3.244–6.247 |
TNR-20 | 4.498–6.247 | 4.498–6.247 |
TNR-16 | 5.587–10.768 | 5.587–10.768 |
Table 9.
Signature resonance frequencies for letter tag ه with various font types and sizes (* represents resonant frequency out of analyzed frequency range).
Table 9.
Signature resonance frequencies for letter tag ه with various font types and sizes (* represents resonant frequency out of analyzed frequency range).
| Vertical Polarization | Horizontal Polarization |
---|
Arial-28 | 7.754–10.108 | 10.108 |
Arial-20 | 10.933–* | – |
Arial-16 | *–* | – |
Calibri-28 | 3.629–5.136–6.852–9.041 | 3.629–5.136–6.85–9.041–11.252 |
Calibri-20 | 5.081–7.171–9.041–* | 5.081–7.171–9.712 |
Calibri-16 | 6.258–9.679–*–* | 6.258–8.92 |
TNR-28 | 7.171–9.679 | 9.679 |
TNR-20 | 10.35–* | – |
TNR-16 | –*–* | – |
Table 10.
Signature resonance frequencies for letter tag و with various font types and sizes (* represents resonant frequency out of analyzed frequency range).
Table 10.
Signature resonance frequencies for letter tag و with various font types and sizes (* represents resonant frequency out of analyzed frequency range).
| Vertical Polarization | Horizontal Polarization |
---|
Arial-28 | 3.475–7.6–10.482 | 3.475–7.6 |
Arial-20 | 4.839–10.526–* | 4.839–10.526 |
Arial-16 | 6.104–*–* | 6.104 |
Calibri-28 | 2.507–6.126–7.534–8.568–10.834 | 6.126–7.534–8.568–10.834 |
Calibri-20 | 3.53–8.557–10.603–* | 8.557–10.603 |
Calibri-16 | 4.498–10.614–*–* | 10.614 |
TNR-28 | 3.255–7.193–9.789–11.846 | 3.255–7.193–11.846 |
TNR-20 | 4.619–10.042–*–* | 4.619–10.042 |
TNR-16 | 5.73–*–*–* | 5.73 |
Table 11.
Change in resonance frequency (Δf) in % in vertical polarization for analyzed tags for the changing font size with reference to Arial-28, Calibri-28, and Times New Roman (TNR)-28 tags.
Table 11.
Change in resonance frequency (Δf) in % in vertical polarization for analyzed tags for the changing font size with reference to Arial-28, Calibri-28, and Times New Roman (TNR)-28 tags.
Font Size | Δf (%) |
---|
| Tag د | Tag ر | Tag ه | Tag و |
Arial-20 | 39.4 | 1.0 | 41.0 | 39.3 |
Arial-16 | 73.1 | 71.9 | - | 75.7 |
Calibri-20 | 40.4 | 38.4 | 40.0 | 40.8 |
Calibri-16 | 78.0 | 74.4 | 72.4 | 79.4 |
TNR-20 | 43.7 | 38.7 | 44.3 | 41.9 |
TNR-16 | 77.5 | 72.2 | - | 76.0 |
Table 12.
Comparison of the proposed design of printable chipless RFID Arabic letter tags design with legacy designs.
Table 12.
Comparison of the proposed design of printable chipless RFID Arabic letter tags design with legacy designs.
Ref. | Design Type | Substrate | Metallic Material | Tag Ground Plane | Font Type (Height in mm) | Freq. (GHz) | No. of Resonators per Tag | Size (cm2) | RCS Analysis | Analysis of Structural Modifications |
---|
[6] | Single letter Latin alphabet | Kapton | Copper | No | Arial (24) | 1–10 | 1 | 3.7 × 3.7 | Yes | No |
[24] | Single letter Latin alphabet | Kapton | PEC | No | Arial (48) | 1–10 | 1 | 4.8 × 4.5 | No | No |
[1,2] | Peyote symbols of five letters | FR4 and Mylar
Polyester Film | Al | No | Blocks building | 57–64 | 5 | 5 × 1 | No | No |
[25] | Latin alphabets letters and words with slots | – | – | No | Calibri (53) | 1–10 | 3 | 5.3 × 9 | Yes | No |
[9] | Latin alphabet letters and three letters words | TLX-8 | Copper | Yes | Arial, Corbel, Times New Roman (15–16.4) | 6–13 | 3 | 4 × 2 | Yes | Yes |
[12] | Single letter Arabic Alphabets | Kapton | PEC | No | Arial (24) | 1-10 | 1 | 3.7 × 3.7 | No | No |
[4] | Single letter Arabic alphabets | Kapton | Copper | No | Arial with dots (24) | 2–8 | 1 | 3.7 × 3.7 | Yes | No |
This work | Arabic alphabet letters | Paper | Copper | Yes | Arial, Calibri, Times New Roman (16, 20, 28) | 1–12 | 1 | 4 × 5 | Yes | Yes |