Comparison of two matching techniques for UHF RFID tags

Abstract

respectively. In the Figure 8A,B, the simulation results for S 11 and S 41 are 44.1 and 37.6 dB and the measurement results for S 11 and S 41 are 42.9 and 36.6 dB, respectively. Table 5 shows the is on for comparison for dimension size of the proposed HBC and other HBCs. In the table, the proposed HBC size is reduced the 83% then conventional HBC (see Figure 1). 1,10,11 | C ONCL US I ONIn general, the kg/4 transmission-line (TL) is used for HBC in the microwave system. The dimension size of the conventional kg/4 TL is increased at the low frequency band due to long wavelength. In this article, the new compact-size of the TL usingp-type parameter is suggested and it applied to the design of a HBC. In this characteristic, the HBC is very small size than conventional HBC and the size of the new and conventional HBCs are 9.86 3 11.1 mm 2 and 28.2 3 28.6 mm 2 , respectively. The new structure of the HBC is used by whole distributed elements. The advantage of the proposed HBC structure has very simple structure and low cost. Also, the proposed HBC consists of planar structure. Thus, the proposed structure can also be adequate in a monolithic microwave integrated circuit fabrication due to planar structure. The proposed HBC using p-type TL can be applied to mobile communication system. ORCID Ki-Cheol Yoon AbstractThis Letter reports a comparison between shunt-series inductance (SSI) and inductively coupled loop (ICL) matching circuits for ultra high frequency (UHF) Radio Frequency IDentification (RFID) tags. It is shown analytically that an optimized ICL circuit is fully equivalent to an optimized SSI circuit provided that some adjustments are made on the dipole antenna geometry. Numerical and GOURARI ET AL. | 1763

Bendable ultra‐high frequency radio‐frequency identification tag antenna for retail garments using nonuniform meandered lines

“…The reading range of the proposed tag is measured with 5° rotation along the axis. To corroborate the measured results, the read range of the tag is calculated theoretically with Friss equation 17 …”

“…Several design approaches have already been discussed for impedance matching and size reduction of RFID tags, which include T‐Matching, 13‐15 inductively coupled loop, 16 and meander line antennas. For instance, the inductive coupling technique improves impedance matching of a tag antenna with little effect on the radiation efficiency 17 . Similarly, the T‐matching technique 18 achieves a broadband matching, reduced size, and improved efficiency.…”

Compact meandered RFID tag antenna with high read range for UHF band applications

“…The calculated value of R rad is found to be 7.05 Ω. The capacitance of the radiating element, C rad and inductance of the radiating element, L rad , can be derived using and , where Q ant is the quality factor of antenna and can be approximated from the simulated reactance ( X in ) slope of the tag antenna in CST Microwave Studio as defined in Reference 28, 29 using where f 0 is the center frequency of the tag antenna, df = f 2 − f 1 , dX in = X in ( f 2 ) − X in ( f 1 ). The computed values of C rad and L rad are 1.85 pF and 16.308 nH respectively.…”

“…Equivalent circuit of proposed RFID tag shown in Figure . Can be further simplified using equivalent T model of transformer described in Reference 28, shown in Figure .Where = 28.54 nH and =13.99 nH respectively. To compute the input impedance, Z in , using various derived parameters (,, C rad , M ), equivalent T model is realized using ADS software.…”

All-in-One Uhf Rfid Tag Antenna for Retail Garments Using Nonuniform Meandered Lines

“…In the literature, various techniques have been reported to achieve the aforementioned specifications. For instance, the inductive coupling technique improves impedance matching of a tag antenna; however, it compromises radiation efficiency [8]. Similarly, the T-matching technique [2,9] achieves broadband matching, reduced size, and improved efficiency, but the designs [10,11] do not consider the effect of magnetic locks on the cloth tags.…”