A compact wideband circularly polarized quadrifilar antenna with PIFA elements for UHF RFID readers

2020 ◽  
Vol 12 (10) ◽  
pp. 1020-1028
Author(s):  
Chawanat Lerkbangplad ◽  
Alongkorn Namahoot ◽  
Prayoot Akkaraekthalin ◽  
Suramate Chalermwisutkul

AbstractIn this paper, a compact circularly polarized quadrifilar antenna with planar inverted-F antenna (PIFA) elements is presented. The proposed antenna consists of four PIFA elements and a Wilkinson divider-based feed network fabricated on FR-4 substrate (ɛr = 4.4, loss tangent = 0.02, thickness = 1.6 mm). The total size of the antenna is 120 × 120 × 13.2 mm3. Impedance matching with a reflection coefficient <−15 dB and an axial ratio (AR) <3 dB are achieved over the global ultra-high frequency (UHF) radio frequency identification (RFID) frequency band and beyond. The realized gain ranges from 2.25 to 3.75 dBic within the frequency band of interest from 860 to 960 MHz with a directional radiation pattern. The proposed antenna is compact, low-cost and extremely wideband in terms of matching and AR compared to state-of-the-art UHF RFID reader antennas.

2021 ◽  
Vol 36 (6) ◽  
pp. 747-754
Author(s):  
Rui Ma ◽  
Quanyuan Feng

This paper presents a new coplanar waveguide (CPW)-fed circularly polarized square slot antenna (CPSSA). The proposed antenna uses an inverted Z-shaped feedline protruded from the signal line of the feeding CPW. Circularly polarized (CP) radiation can be achieved by adequately inserting the arc-shaped grounded strip into the upper right corner of the square slot. The widened vertical tuning stub on the L-shaped grounded strip can improve impedance matching and axial ratio (AR) performance. The measured results indicate that the 10 dB impedance bandwidth is 620 MHz (652-1272 MHz), and the 3 dB axial ratio bandwidth is 320 MHz (840-1160 MHz), which has a broadband characteristic. In the range of the universal UHF RFID band, the measured peak gain is about 4.4 dBi. The proposed CPSSA uses low-cost FR4 material as the dielectric substrate. The overall size of the antenna is 119 × 119 × 0.5 mm3. The proposed antenna has a simple structure, easy processing, good performance, wide operating bandwidth, and dual circular polarization characteristic. It can be applied to the universal UHF RFID handheld reader environment.


Electronics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 400 ◽  
Author(s):  
Wei Hu ◽  
Guangjun Wen ◽  
Daniele Inserra ◽  
Yongjun Huang ◽  
Jian Li ◽  
...  

A 2 × 2 circularly polarized (CP) sequential rotation microstrip patch antenna array with high gain for long-range ultra-high frequency (UHF) radio frequency identification (RFID) communication is proposed in this paper. In order to meet the operational frequency band requirement of 840–960 MHz and, at the same time, achieve enhanced broadside gain, a two-level sequential rotation structure is developed. Series power divider is used as the basic element of the feed network that is implemented with the substrate-integrated coaxial line technology for minimizing radiation losses. The manufactured prototype exhibits a peak gain of 12.5 dBic at 900 MHz and an axial ratio (AR) bandwidth (AR ≤ 3 dB) of 18.2% from 828 to 994 MHz. In comparison with the state-of-the-art, the proposed antenna shows an excellent gain/size trade-off.


2017 ◽  
Vol 2017 ◽  
pp. 1-5
Author(s):  
Hesheng Cheng ◽  
Jin Zhang ◽  
Hexia Cheng ◽  
Qunli Zhao

A novel compact circular polarization (CP) microstrip antenna is proposed for UHF ultrahigh frequency (UHF) radio frequency identification (RFID) reader applications. The proposed antenna is composed of a corner truncated square-ring radiating patch on a substrate and a vertical slotted ground surrounding four sides of the antenna. A new feeding scheme is designed from flexible impedance matching techniques. The impedance bandwidths for S11<-10 dB and 3 dB axial ratio (AR) bandwidth are 12.1% (794.5–896.5 MHz) and 2.5% (833.5–854.5 MHz), respectively.


2017 ◽  
Vol 9 (8) ◽  
pp. 1741-1748 ◽  
Author(s):  
Mahdi Jalali ◽  
Mohammad Naser-Moghadasi ◽  
Ramezan Ali Sadeghzadeh

Wide-band circularly polarized multi-input multi-output (MIMO) antenna array with a 2 × 4 feed network was proposed for C-band application. Different unique techniques were utilized in the proposed array to enhance the antenna characteristics, such as gain, 3 dB axial ratio bandwidth (ARBW), impedance tuning, and ruinous mutual coupling effects. A miniaturized dual-feed Tai chi-shaped antenna element with a pair of feeding points and a pair of eyebrow-shaped strips was presented for enhancing circular polarization (CP) purity and impedance matching. For a better improvement of CP features, a 2*4 MIMO sequentially rotated (MIMO-SR) feed network was used to achieve broader 3 dB ARBW. Besides, the MIMO feature of the feed network could control the left- and right-handed CP, respectively. Ultimately, specific forms of slot and slit structures were applied onto the top layer of MIMO feed network that provided a high isolation between the radiating elements and array network. Furthermore, the diversity gain (DG) was studied. The extracted measured results illustrated an impedance bandwidth of 3.5–8.2 GHz at port 1 and 3.5–8.3 GHz at port 2 for VWSR < 2 and 3 dB ARBW of 4.6–7.6 GHz at port 1 and 4.6–7.5 GHz at port 2. The peak gain of 9.9 dBi was at 6 GHz.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Waleed Abdelrahim Ahmed ◽  
Feng Quanyuan

This study presents a novel compact circularly polarized antenna for universal ultrahigh-frequency (UHF) radio-frequency identification (RFID) handheld reader applications. The antenna is composed of a coplanar waveguide (CPW) L-shaped feedline mounted at the right edge of the square slot at the bottom of the ground plane to realize a circular polarization; a horizontal stub protruded from the right side of the square slot towards the slot centre, and a vertical stub is mounted at the lower left of the square slot. The designed antenna printed on one ground plane layer of a low-cost FR4 substrate with an overall size of 120×120×1.6 mm3. The measurement results show indicate that the fabricated antenna achieves a wide axial ratio (AR) bandwidth of 460 MHz (818–1278 MHz), wide impedance bandwidth of 54.6% (630–1103 MHz), and a measured peak gain of 4.0 dBi. The proposed antenna is a good candidate for compact universal UHF RFID handheld reader applications (840–960 MHz).


2014 ◽  
Vol 697 ◽  
pp. 425-428
Author(s):  
Yan Zhong Yu ◽  
Yun Yan Wang ◽  
Yan Ru Chen

A miniaturized circularly polarized (CP) antenna for ultra-high frequency (UHF) radio-frequency identification (RFID) reader is designed in the present paper. For the aim of miniaturizing antenna, the square radiating patch is opened by four T-shape slots. This can extend the route of surface current, as a result the operating frequency drops and the size reduces. In additional two diagonal corners of the radiation patch are truncated by a square to achieve CP operation. The designed antenna is calculated and optimized by HFSS. The optimized antenna exhibits satisfied performances, and is therefore suitable for UHF RFID reader applications. The designed antenna shows the advantages of small size, simple structure, and low cost.


2018 ◽  
Vol 7 (5) ◽  
pp. 94-100 ◽  
Author(s):  
S. Pandey ◽  
G. P. Pandey ◽  
P. M. Sarum

A compact, square shaped microstrip fractal antenna with asymmetrical pairs of T-slits for circularly polarized (CP) radiation and radio frequency identification (RFID) reader applications is proposed and experimentally investigated. Design is based on narrow slit modified Minkowski island fractal geometry. Circular polarization along with size reduction is achieved by inserting four symmetrical pairs of T-slits at the square patch boundary of the single-probe-feed radiator. Proposed geometry is tuned at resonant frequency of 914 MHz by optimization of dimensions of the two T-slits. Compactness of the antenna is achieved by increasing the overall sizes of the slits. Antenna is fabricated on FR4 substrate with a size of 47.2×47.2×1.6 mm3 (0.143λ0 X 0.143λ0 X 0.005λ0) and tested to validate the simulated results. The 3-dB axial-ratio (AR) bandwidth and impedance bandwidth of the proposed antenna design are found to be 7 MHz (911-918 MHz) and 24 MHz (909-933 MHz) respectively. A design equation is develped based on the parametric study that can be used to design a compact antenna with CP for UHF RFID applications covering the frequency range from 887 to 1023 MHz.


2021 ◽  
Vol 36 (5) ◽  
pp. 589-595
Author(s):  
Canjie Chen ◽  
Quanyuan Feng

A novel compact printed broadband circularly polarized slot antenna is proposed in this paper. The antenna consists of an inverted L-shaped coplanar waveguide feed structure and a square ground plate loaded with three rectangular slots. The antenna achieves good impedance matching and circular polarization characteristics by adjusting the size of the L-shaped band and the rectangular slot. The simulation results show that the antenna has a 10-dB impedance bandwidth of 1360 MHz (690-2050 MHz) and a 3 dB axial ratio (AR) bandwidth of 490 MHz (770-1260 MHz). Additionally, the maximum gain reached 4.02 dBi. The antenna proposed in this paper can be applied to UHF RFID and GPS frequency bands.


2018 ◽  
Vol 10 (3) ◽  
pp. 328-335
Author(s):  
Saeed Mohammadi-Asl ◽  
Javad Nourinia ◽  
Changiz Ghobadi ◽  
Maryam Majidzadeh

Compact broadband circularly polarized elliptical slot antenna arrays (CPESAAs) are devised based on 2 × 2 and 4 × 4 circularly polarized (CP) elliptical slot antennas and a sequential phase feed network. To realize the circular polarization, eight rectangular stubs are embedded in the feed structure to excite two orthogonal E vectors in 2 × 2 CPESAA configuration. Moreover, by taking four rectangular slots out from each array element, return loss and axial-ratio bandwidths are noticeably increased. The investigated simple array element has a compact size of 20 × 20 × 1 mm3. As well, 2 × 2 CPESAA occupies a compact size of 55 × 60 × 1 mm3, which operates within the frequency band 4.18–9.35 GHz. Thus, 76.4% of S11< −10 dB and 51.4% of CP bandwidth (4.43–7.5 GHz) are covered. Moreover, proposed 4 × 4 CPESAA is printed on 110 × 110 × 1 mm3FR4 substrate and covers the frequency band of 1.15–12.98 GHz with CP at 2.95–8.82 GHz. Throughout the study, the design process of the proposed antenna arrays are presented and discussed in detail.


2015 ◽  
Vol 9 (1) ◽  
pp. 171-175 ◽  
Author(s):  
Puria Bairami ◽  
Mahdi Zavvari

In this paper, an array antenna with asymmetric antenna fed network is presented. Total size of the proposed array antenna (with 2 × 2 elements) is 90 × 90 mm2 and distance between elements (fed by fed) is λ0/2 (λ0 = wavelength in free space). The proposed antenna is fed by coaxial cable that isolated input impedance from impedance of the array antenna feed network. The measured impedance bandwidth of the coaxial fed circular polarization array (S11 < −10 dB) is 47.9% from 4.6 to 7.5 GHz (1.63:1), and the measured 3-dB axial-ratio bandwidth is 42% from 4.7 to 7.2 GHz. The peak gain of antenna is 9.1 dBic.


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