Md. Aminul Islam

A Novel Compact Printable Dual-Polarized Chipless RFID System

A novel compact design of an ultralow-cost fully printable slot-loaded dual-polarized chipless radio frequency identication tag is presented with four near- and far-field reading techniques. The tag consists of four rectangular metallic patches loaded with multiple slot resonators. Slots with the same polarization for adjacent frequencies are placed alternately into two patches to reduce the mutual coupling between the slots. Then two similar sets are placed in horizontal and vertical polarizations to double the number of bits within the same frequency bandwidth. The tag can be detected using dual-polarized waveguide(s) or dual-polarized antennas. This single-sided compact chipless tag has higher data capacity and lower cost compared with the existing printable chipless tags and can be used in personal ID or credit cards and banknotes and can be directly printed on paper or plastic packets for item-level tagging.

Orientation independent compact chipless RFID tag

A design concept of a compact printable orientation independent chipless radio frequency identification tag is presented with near-field and far-field reading techniques. The tag consists of a circular patch loaded with multiple slot ring resonators and it has the advantage to be read from any orientation with the reader due to its symmetric structure. This tag does not have a ground plane and has higher data density and lower cost compared to the most other existing printable chipless tags. Proximity and slot reading techniques are described in details for different applications. This single-sided, compact and orientation independent tag has a great potential to be used in millions both for identification and authentication.

COMPACT PRINTABLE ORIENTATION INDEPENDENT CHIPLESS RFID TAG

A novel design concept of a compact printable orientation independent chipless RFID tag is presented. The tag consists of a circular patch loaded with multiple slot ring resonators. This symmetric frequency domain based tag has the advantage to be read from any orientation with the reader antennas. The tag can be read in close proximity by chipless RFID tag reader with waveguide(s) and also can be read in both near fleld and far-fleld of the RFID tag reader with antennas. This tag does not have a ground plane and has higher data density compared to the existing printable chipless tags. The usability of this single sided tag in close proximity is verifled by waveguide measurements for both proximity applications such as on ID access cards, item level tagging etc. and slot reading application such as on banknotes, credit cards etc.

A

A 4 × 4 dual polarized (DP) aperture-coupled microstrip patch antenna (ACMPA) array for a universal millimeter (mm)-wave chipless RFID tag reader is presented. The mm-wave DP ACMPA array is capable of reading all types of frequency domain-based chipless RFID tags (linearly polarized, orientation insensitive, cross-polarized (CP), and DP) within its operating frequency bandwidth. The developed antenna is operating over the 22-26.5-GHz frequency band with 16-dBi realized gain and over 35-dB isolation. A systematic approach is followed up for designing the mm-wave antenna array where, first, a single antenna element is designed. Then, a 1-32-way corporate feed network for the dual offset feeding of cross slots is designed using multistage power dividers. After that, the 4 × 4 mm-wave DP ACMPA array is designed, optimized, fabricated, assembled, and tested. Simulation and measurement results for different development stages of the array are described in detail. Finally, the assembled antenna is used for measuring 10 orientation insensitive (OI) thermal printed mm-wave chipless RFID tags on a paper substrate to validate its functional accuracy. The developed mm-wave DP ACMPA array with high port-to-port isolation can be used in a universal commercial mm-wave chipless RFID tag reader due to its low cost, high gain, and low-profile structure.

4 \times 4

Two novel compact printable chipless RFID systems are presented, which are: 1) a dual-polarized (DP) system and 2) an orientation insensitive (OI) system. Chipless tags for both the DP and OI systems consist of horizontally (H) and vertically (V) polarized “I” shaped slot resonators of different lengths, which create frequency signatures in the backscattered signal. Here, different V-H slots are used in the DP tag to double the encoding capacity within a fixed bandwidth and same V-H slots are used in the OI tag to achieve orientation insensitivity. Next, for reading these DP and OI tags, a low-profile low-cost wideband DP aperture coupled microstrip patch antenna (ACMPA) with high port-to-port isolation is developed as well. A reader with DP transmission and reception is capable of reading both the DP and OI tags. These single-sided compact tags are directly printable using conductive ink. Here, DP tags with double data capacity are suitable for fixed orientation applications demanding high data capacity, whereas OI tags are suitable for low data capacity applications requiring orientation insensitivity. Moreover, the developed commercially suitable DP ACMPA can also be used universally for reading all other frequency-domain-based tags.

Dual Polarized mm-Wave ACMPA Array for a Universal mm-Wave Chipless RFID Tag Reader

A 4×4 aperture coupled UWB microstrip patch antenna array for mm-wave chipless RFID tag reader is presented. The antenna is operating over the 21-27 GHz frequency band with 20 dBi gain. A systematic approach has been followed to design the antenna array, where, firstly a single antenna element is optimized, then a feed network using multistage power divider is designed and finally, the 4×4 antenna array is developed and optimized. Simulation and measurement results of the antenna are described in details with gain, radiation pattern and impedance behavior. Finally, the assembled antenna is used for measuring mm-wave chipless tag to validate its functional accuracy. The antenna can be used in commercial mm-wave chipless RFID tag reader due to its lower profile, cost and higher gain.

Compact Printable Chipless RFID Systems

The design architecture of a reader for detecting dual polarized chipless RFID tags is presented. The proposed reader is based on ultra-wideband chirp signal interrogation for multi-resonator based chipless RFID tags. Here, linear chirp signal is generated to read the tag data in amplitude signatures for both polarizations. The advantage of this very low cost design using single voltage-controlled oscillator (VCO) is that, it does not require any calibration tag to decode the tag data, and can read the dual polarized tags and other tags which required measurement in both polarizations. Moreover, the former linearly polarized version of the chipless tags can also be measured using this reader.

Aperture coupled UWB microstrip patch antenna array for mm-Wave chipless RFID tag reader

In spite of wide use of projection-based features in handwritten character recognition of several languages, its implementation was somewhat scanty in Bangla handwritten character recognition. This paper introduces the usage of projection profile features in recognizing handwritten Bangla basic characters. Alongside it also demonstrates a qualitative and quantitative analysis to visualize the effect of using projection based features on accuracy of recognition of Bangla handwritten characters through a number of approaches. In fact, this particular effort comprises of five different approaches where first one used longest-run, quad-tree and octant centroid features, second one adopted additional shadow features in association with the features of first approach, third one used longest run, quad-tree, shadow and chain code histogram features, next approach used longest-run, quadratic center of mass, shadow and left projection profile features and finally fifth approach with additional right projection profile features along with other features involved in the fourth approach. Throughout this analysis, neural network (trained via back-propagation algorithm) acted as classifier to observe the change in accuracy of recognition. It is seen that, with the increase in number of projection-based features, percentage of accuracy enhances at a greater rate than in case of inclusion of other features. This effective analysis can certainly assist a researcher to choose the optimal feature vector (consisting of several feature sets) for handwritten Bangla basic characters recognition.

A novel reader architecture for chipless RFID tags

A single element linearly polarized (LP) aperture coupled microstrip patch antenna (ACMPA) in microwave frequency band is presented in this paper. The paper starts with the requirement for developing a low profile, low cost, lightweight, wideband LP antenna suitable for commercial chipless RFID tag readers. Then, a thorough review is done on existing low profile wideband antenna designs to find out a suitable match with all required reader antenna specifications. From the literature analysis, ACMPA design technique is found as the best match for developing the reader antenna, which is followed next. First, antenna specifications are listed for developing a single element LP ACMPA. Then, a single element is designed and optimized to achieve the targeted values, which is fabricated and assembled next. After that, this ACMPA is measured in a vector network analyzer (VNA), which fulfills the set targets. Next, tag reading performance of the antenna in three different measurement setups is evaluated through measurement of ‘O’ slot loaded orientation insensitive (OI) tags. These tag measurement results have confirmed the usability of the developed antenna in commercial tag reader.

Projection-based features: A superior domain for handwritten Bangla basic characters recognition

A novel design concept of a compact printable chipless RFID tag is presented. The tag consists of a triangular patch loaded with multiple triangular ‘Δ’ shaped slot resonators. Six copies of the identical patches are placed together to achieve a very compact long range chipless RFID tag. This symmetric frequency domain based tag has the advantage to be read from any orientation with the reader antennas. The tag can be read by chipless RFID tag reader in both near field and far-field measurements. This tag does not have a ground plane and has higher data density compared to most of the existing printable chipless tags.