On the Performance of a Microstrip Antenna Based UC-PBG Structures for UHF RFID Readers

Abstract

Microstrip antennas suffer from low gain bandwidth product due to surface wave effects and aperture diffractions that limit their use for longrange communications. On top of that, the difficulty of achieving a pure circularly polarized radiation with high gain due to the feeding structure effects. This paper is subjected to design a gain enhanced circularly polarized patch antenna using Uniplanar Compact-Photonic Band Gap (UC-PBG) structu.res for UHF RFID applications. The patch is structured as truncated corners with cross slots at the centre mounted on an FR-4 epoxy substrate of 1.6mm thickness with an overall area of 188×188mm 2. The UC-PBG is constructed of two layers; each is made of 7×7 unit cells, separated by 20mm mounted from the top of the patch at 30mm height. The unit cell characterizations are evaluated in terms of their S-parameters and dispersion diagram CST-MWS environment. The antenna shows a boresight gain of about 8.2 dBi at 915MHz with a front to back ratio (F/B) of 13dB. The benchmark enhancement in boresight gain after adding the UC-PBG layers is found to be 3.4 dBi with a radiation efficiency of 87%. Finally, an excellent agreement is achieved between the obtained measurements and numerical results.

Novel reconfigurable monopole‐based matching circuitry design for 5G and modern wireless communication systems

“…Thus, four PIN diodes are connected between the L‐shaped reflector and the MLC inclusion to control the matching bandwidth and the radiation patterns within 16 scenarios. We found that the proposed antenna shows excellent and stable variation in the radiation patterns direction as well as the bandwidth, because there is no direct connection between the PIN diodes and the monopole structure that isolated the RF source from the DC source completely 8 . In Table 4, the proposed antenna is tested numerically, and the performance of the antenna in terms of frequency resonance, S 11 , gain, and bandwidth (B.W) is summarized.…”

“…We found that the proposed antenna shows excellent and stable variation in the radiation patterns direction as well as the bandwidth, because there is no direct connection between the PIN diodes and the monopole structure that isolated the RF source from the DC source completely. 8 In Table 4, the proposed antenna is tested numerically, and the performance of the antenna in terms of frequency resonance, S 11 , gain, and bandwidth (B.W) is summarized. It is found that the proposed antenna shows maximum gain, about 4.72 dB, at 0001 case, in which D 1 , D 2 , and D 3 are OFF and D 4 is ON.…”

“…Nevertheless, meta‐surfaces were introduced in various antenna structures as defected ground planes, 3 frequency selective surfaces, 4 and artificial magnetic conductors 5 . Most of these applications were applied to wearable textile WBAN applications, 6 size reduction, 7 antenna gain enhancement, 8 interference isolation, 9 and mutual coupling reduction 10 . Moreover, these artificial structures provided unique features such as distinctive stop bands, 11 surface wave suppressions, 12 and negative effective constitutive parameters 13 …”

Notched Circular EBG based Circularly Polarized Antenna for Performance Enhancement

“…Many researchers have worked in this field and have used these structures as high impedance structures [19], metasurfaces [20], polarization-dependent EBG surfaces [21], etc. When implemented on antenna's ground plane, EBG structures showed an improved performance [22][23][24]. The attractive features of EBG structures has made these structures be used in broad area of applications in the antenna field.…”