A Compact Grounded Asymmetric Coplanar Strip-Fed Flexible Multiband Reconfigurable Antenna for Wireless Applications

Abstract

A compact grounded asymmetric coplanar strip (GACS)-fed flexible multiband frequency reconfigurable antenna with two PIN diodes is proposed. The investigated antenna is backed by a flexible polyamide substrate with compact dimensions of 24 mm × 19 mm and a thickness of 1.53 mm. The investigated antenna structure contains a monopole patch that facilitates operation for wireless LAN applications, whereas inverted L-shaped and F-shaped monopoles facilitate operation for Bluetooth and 5G NR applications. The investigated antenna operates at 2.4, 3.8, and 5.6 GHz with measured impedance bandwidths of 5.8%, 6.3%, and 6.6%, respectively, over the three frequency bands, thus facilitating coverage for Bluetooth, 5G NR, and WLAN standards. The two PIN diodes are employed to tune the investigated antenna among four modes, including a single band mode (WLAN 5.5 GHz), two dual-band modes (5G NR 3.8/5.6 GHz, and Bluetooth 2.48/5.6 GHz), and one multiband mode with Bluetooth (2.4 GHz), 5G New Radio (NR) N77 band (3.8 GHz), and WLAN (5.6 GHz) modes. The investigated antenna radiates unidirectionally with a peak gain of 3.73 dBi at 5.6 GHz. Measurements are carried out on the human body to investigate the behaviour of the wearable antenna. The simulated SAR values are in a safe limit of 1.6 W/kg for 1 g of tissue, according to the FCC. Moreover, the investigated antenna shows extremely low vulnerability to degradation in performance as a result of bending effects concerning impedance matching with acceptable acquiescence between measurements and simulations.

Miniaturized Broadband-Multiband Planar Monopole Antenna in Autonomous Vehicles Communication System Device

“…The antenna's gain also has a comparable measurement result to the literature [26][27][28][29][30]. The antenna size of the proposed antenna is smaller than in the literature [26][27][28][29][30]. The system ground size is smaller than the literature [26,30].…”

“…This table uses the journal papers of the past two years for antenna design comparison. The proposed antenna design has a larger bandwidth than the literature [26][27][28][29][30]. The antenna's gain also has a comparable measurement result to the literature [26][27][28][29][30].…”

“…The proposed antenna design has a larger bandwidth than the literature [26][27][28][29][30]. The antenna's gain also has a comparable measurement result to the literature [26][27][28][29][30]. The antenna size of the proposed antenna is smaller than in the literature [26][27][28][29][30].…”

“…The validation tool employed an EM simulator for simulation results and a vector network analyzer as the equipment of Agilent E7071C for measurement results. The measured impedance bandwidths are defined by 3:1 VSWR, widely used for the internal WWAN antenna design specification [26][27][28][29][30]. The antenna bandwidth defined by VSWR is 3:1 to match the CTIA specification standard with the built-in WWAN antenna design integrated RF active circuit application.…”

An Autonomous Frequency Reconfigurable Antenna Using Slotline Open-Loop Resonators

“…Recently, the frequency reconfigurable antennas in various topologies of slotline with branch edge [5], composite right/left hand (CRLH) transmission line [6], [7], geometrical slots excited by feed line [8], [9], bow-tie microstrip [10], [11], Quasi-Yagi dipole [12], [13], wideband/dual-band microstrip patch [14]- [16], half annular ring slot [17], metamaterial inspired [18], and tunable slot [19], are proposed. In addition to this, frequency reconfigurable antennas with different radiating structures such as U-shaped slot [20], rectangular loops with partial patch [21], circular patch [22], monopole configuration [23], quadrifilar helix [24], loop antenna with independent tuning [25], grounded asymmetric CPW fed planar [26], U-shaped monopole radiator [27], and substrate integrated waveguide based reconfigurable antenna [28] are reported. In the antennas mentioned above, a PIN diode/varactor diode is inserted on the specified slots for the effective controlling of frequency bands because they possess low threshold voltage and flexible mounting configuration.…”