Algorithm for the Fewest Arms Required by Multi-Band Linear Dipole Antenna

Small linear dipole antennas with a multi-band characteristic are necessary for many strip or bar shaped gateway devices of the Internet of Things (IoT), for the connectivity in various communication protocols. However, the conventional methodology of designing multi-band dipole antennas is generally empirically based. More frequency bands usually mean even more arms/slots, which results in an increasingly bulky antenna. In this paper, we will introduce an algorithm of using the fewest arms to design a multi-band linear dipole antenna. This algorithm is based on sharing arms after the effective ranges of mode excitation are determined by characteristic mode analysis (CMA). By this algorithm, an exemplified designed penta-band dipole antenna is effective in covering 433, 868, 1176, 1575, and 2450 MHz bands for LPWAN, GNSS, and ISM applications, with only 2.5 pairs of arms. 50% of arms are reduced in comparison to traditional methods. This algorithm is convenient in practical dipole antenna design, and greatly simplifies the antenna structure so that they could be mounted into small IoT devices.

Algorithm for the Fewest Arms Required by Multi-Band Linear Dipole Antenna

Small linear dipole antennas with a multi-band characteristic are necessary for many strip or bar shaped gateway devices of the Internet of Things (IoT), for the connectivity in various communication protocols. However, the conventional methodology of designing multi-band dipole antennas is generally empirically based. More frequency bands usually mean even more arms/slots, which results in an increasingly bulky antenna. In this paper, we will introduce an algorithm of using the fewest arms to design a multi-band linear dipole antenna. This algorithm is based on sharing arms after the effective ranges of mode excitation are determined by characteristic mode analysis (CMA). By this algorithm, an exemplified designed penta-band dipole antenna is effective in covering 433, 868, 1176, 1575, and 2450 MHz bands for LPWAN, GNSS, and ISM applications, with only 2.5 pairs of arms. 50% of arms are reduced in comparison to traditional methods. This algorithm is convenient in practical dipole antenna design, and greatly simplifies the antenna structure so that they could be mounted into small IoT devices.

A Phased Array Antenna with New Elements Designed Using Source Transformations

Transformation electromagnetics/optics (TE/TO) has been shown to be a useful technique in designing electromagnetic devices with very unique properties. Here, the concepts of transformation optics for single elements is extended to an array of “pinwheel” shaped elements for the first time. Through full-wave finite element analysis (FEA), it is shown that a transformed “pinwheel” linear array can be designed to operate identically to a uniformly spaced linear dipole array. Thus, the “pinwheel” antenna array will maintain all the advantages of array processing of a simple dipole antenna array. The proposed method has applications in structurally integrated and conformal phased arrays for wireless communications, radars, and sensing where structural and mechanical constrains do not align with antenna performance.

Structure optimization of an ultrahigh frequency radio frequency identification tag thread based on the normal mode helix dipole antenna

This paper describes the design of a novel ultrahigh frequency radio frequency identification (UHF RFID) tag thread that mainly consisted of the common yarn and the normal mode helix dipole antenna. The linear dipole antenna for the UHF RFID tag thread was too long to miniaturize the tag. In order to maximize the read performance and miniaturize the size of the tag, the basic antenna structure parameters, such as the helical pitch and single arm length, were optimized by analyzing the radiation parameter S11 of the normal mode helix dipole antenna based on simulation experiments. The simulation experiments started with optimizing the single arm length to obtain the minimum of the S11 parameter at resonant frequency, then the helical pitch was further optimized to limit the resonant frequency to the UHF range. The simulation results showed the resonant frequency rises with an increase of helical pitch and declines with an increase of single arm length. Furthermore, a series of UHF RFID tag threads with good performance from the simulation cases were prepared, and the performance of the optimized tag was validated. Generally, the UHF RFID tag thread with optimized helix dipole antenna could reduce the axial length of the tag by 57% and improve the reading range by 500%, and its performance was greatly superior to that of the UHF RFID tag thread with the classical linear dipole antenna.