Table 2.
Spectral Radio Frequency Identification (RFID) Tag Comparison.
| Tag Design | Year | Major Dimensions | Bits Encoded | Spectral Use | Starting Frequency | Read Range | Reader | Polarization | Advantages | Disadvantages | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| SIR TL | 2011 [79] | Length > 100 mm * | 2 | 80 MHz | 970 MHz | 27 | 17 | n/a | n/a | Linear | Printable, single-plane design | Sub-mm tolerances. Approximately 50 mm per bit encoded |
| 2016 [84] | 5 × 2.5 cm * | 1024 (Theory) | 5.8 GHz | 180 MHz | 30 | 10 | 2 mm | n/a | n/a | Printable, single-plane design | Requires UWB interrogation | |
| Spiral TL | 2009 [88] | 88 × 65 mm | 35 | 4 GHz | 3 GHz | 12 | 3 | 5–40 cm | VNA (PNAE8361A) | Cross-Polar | Spirals are compact resonators | Designed for 0.4 m read range. Sub-mm tolerances on spirals |
| 2010 [5] | n/a | 6 | 1.6 GHz | 2 GHz | 20 | 5 | 10 cm | n/a | Linear | Single Antenna Design. Spectrally efficient | Tight fabrication tolerances on spirals | |
| Spiral TL Group | 2018 [126] | 14 cm2 | 20 | 1.2 GHz | 2 GHz | 15 | 5 | 25 cm | VNA (R and S ZVA 40) | Largely omni-directional | Compact, single layer design | 66% variation in spectral dips |
| Stub Loaded TL | 2019 [89] | 23.8 × 17 mm * | 10 | 1.84 GHz | 2 GHz | 20 | 3 | n/a | VNA | n/a | Simplistic, compact design | Significant variations in stub insertion loss |
| 2018 [90] | 53 × 34 mm | 12 | 3.25 GHz | 3 GHz | 35 | 22 | n/a | n/a | Cross-Polarized | Compact and smaller variations in stub insertion loss | Uses a significant amount of the spectrum. Only designed for 0.4 m ranges | |
| 2015 [92] | 28 × 20 mm * | 18 | 3 GHz | 3.1 GHz | 15 | 12 | 20 cm | VNA | Cross-Polarized | Very stable stub responses | Uses a significant amount of the spectrum | |
| 2012 [91] | 30 × 25 mm | 8 | 2.2 GHz | 1.9 | 25 | 8 | 40 cm | VNA (PNA E8362B) | Cross-Polarized | Simplistic Design | Only tested at 0.4 m but response was relatively robust | |
| Resonator Based | ||||||||||||
| SIR | 2014 [82] | 42 × 20 mm | 8 | 5.6 GHz including harmonics | 3.4 GHz | 18 | 5 | 20 cm (tests) 40 cm | VNA (PNA E8362B) | Linear | Printable, single-plane design | Uses large amount of spectrum. Only 0.5 m read range recorded |
| 2016 [83] | 55 × 35 mm | 46 | 7.5 GHz | 3.1 GHz | 8 | 3 | 25 cm (tests) 50 cm | VNA (PNA E8362B) | Linear | |||
| Dipole Based | 2014 [99] | 59 × 17 mm | 3 | 3 GHz | 2 GHz | 18 | 7 | 45 cm (tests) 1 m | VNA (PNA E8362B) | Linear | 1 m read range was achieved with 3 dBm Tx power | Relatively large |
| 2018 [100] | 40 × 40 mm | 6 | 4 GHz | 3 GHz | 7 | 3 | 50 cm | VNA | Linear | Simple design with relatively loose tolerances | Not very compact | |
| 2005 [102] | Approximately 50 × 20 mm | 5–11 | 1.1 GHz | 5 GHz | 5 | 2 | n/a | VNA | Linear | Simple design | Not very compact | |
| 2019 [101] | 20 × 20 mm | 8 | 3 GHz | 3 GHz | 20 | 10 | 45 cm | VNA | Omni-directional | Compact. Orientation-independent | Still not as compact as stub loaded TL tags | |
| 2018 [103] | 15 × 15 mm | 6 | 3.5 GHz | 4 GHz | 35 *** | 30 *** | n/a | n/a | ||||
| 2011 [93] | 15 × 15 mm | 16 | 6 GHz | 6 GHz | 10 *** 4 | 2 *** 2 | n/a | VNA (PNA E8361A) | Dual Polarized | Very compact | Poor spectral response | |
| 2016 [127] | 6.8 × 5.5 mm | 3 | 2 GHz | 8.5 GHz | 10 *** | 5 *** | <50 cm | VNA | ||||
| 2017 [105] | 4.5 × 4.5 mm | 4 | 1.4 GHz | 3 GHz | 4 | 2 | 10–20 cm | USRP | Cross-Polar | Very compact | Poor resonant response | |
| Hairpin/C-shaped | 2011 [97] | 40 × 20 mm | 10 | 4 GHz | 2.5 GHz | 18 | 2 | 45 cm | VNA (HP 8720D) | Linear | Encodes in phase and frequency | Not very compact |
| 2016 [96] | 26 × 70 mm | 20 | 2 GHz | 2 GHz | 15 | 4 | 30 cm | VNA (ZVA 40) | Linear | Large bit-density | ||
| 2017 [95] | 40 × 20 mm | 10 | 3 GHz | 2.4 GHz | 25 | 4 | n/a | n/a | Linear | More spectrally efficient than earlier tag | ||
| 2018 [94] | 121 × 10.5 mm | 1 | n/a | 950 MHz | n/a | n/a | n/a | VNA (PNA-X) | Linear | Operates in ISM band | ||
| Slotted Resonator | 2015 [98] | 30 × 30 mm | 12 | 7 GHz | 3 GHz | 4 | 1 | 15 cm | VNA (AV 3629D) | Linear | Relatively compact | Poor spectral use/response |
| 2017 [104] | 24.5 × 25.5 mm | 36 | 13 GHz | 5 GHz | 6 | 2 | n/a | VNA (ZVL13) | Linear | Far more compact | Poor spectral use/response | |
| Ring Resonator | 2012 [106] | 15 × 15 mm | 8 | 6.5 GHz | 6 GHz | 10 | 5 | 20 cm | VNA (PNA E8361A) | Omni-directional | Very compact | Appears to be parasitic coupling between rings |
| 2012 [108] | 30 × 30 mm | 19 | 7.5 GHz | 3.1 GHz | 4 | 2 | 40 cm | VNA (8722D) | Omni-directional | Very compact | Poor spectral response | |
| 2015 [111] | n/a | 8 | 2 GHz | 2.5 GHz | 15 | 5 | 35 cm | USRP2 | Omni-directional | Compact | Apparent low bit-density | |
| 2016 [112] | 20 × 20 mm | 10 | 7 GHz | 4 GHz | 25 *** | 15 *** | n/a | n/a | Omni-directional | Compact | ||
| 2018 [109] | <98 × 98 mm | 13 | 5.5 GHz | 3 GHz | 35 *** | 7.5 *** | n/a | n/a | Omni-directional | Robust RCS response | Significant redundancy in design | |
| Grouped Loop Resonators | 2016 [115] | 20 × 40 mm | 28.5 | 7 GHz | 3 GHz | 15 | 5 | 38 cm | VNA (PNA-LN5232A) | n/a (Bi-directional) | Relatively compact | Only tested up to 30 cm away |
| Grouped LC Resonators | 2011 [120] | 150 × 210 mm | 10 | 110 MHz | 10 MHz | 24 | 22 | 21 cm | VNA | n/a | Address can be modified. Low frequency operation | Not very compact |
| Grouped Rhombic Resonators | 2013 [128] | 70 × 40 mm | 6 | 3 GHz | 3 GHz | 11 | n/a (ASK) | 20 cm | VNA (PNA E8358A) | Linear | Implements ASK—More efficient than OOK | Not very compact |
| Grouped SRRs | 2010 [118] | >18.5 × 8 mm | 4 | 4 GHz | 8 GHz | 35 *** | 25 *** | n/a | n/a | Linear | Simulation and Testbed response appear good | Sub-mm fabrication tolerances (0.0 × mm). Some coupling still exists |
| Space Filling Curves | 2006 [129] 2010 [123] |
Approximately 150 × 30 mm | 5 | 1.5 GHz | 3 GHz | 5 | 2 | 1.22 m | VNA (E-5071B) | n/a—supports bi-directional | Good use of spectrum space | Poor measured resonant response |
| SIW Resonator | 2019 [130] | Approximately 25 × 20 mm | n/a | 13 GHz | 22 GHz | 35 | 15 | 10 cm | n/a | n/a orthogonal | Less regulations at these frequencies | Microstrip elements have high losses at these frequencies. More expensive reader required |
* Without antennas attached, *** In simulation only. The values in a real implementation can be significantly lower.