No abstract

No abstract

A novel single‐fed dual‐band circular‐polarization (CP) reconfigurable liquid dielectric resonator antenna (LDRA) using 3D printing technology is proposed in this article. With the quasi‐TE111 and ‐TE113 modes of the rectangular LDRA excited, a dual‐band design is achieved. To realize the CP reconfigurability, a combined container, holding the fluidic dielectric (Ethyl acetate, ε r = 6.6), is fabricated by 3D printing technology. Therefore, the CP can be switched between two different states: (1) left hand CP (LHCP), when the right oblique container is full of the liquid solution; (2) right hand CP (RHCP), when the liquid solution is transferred into the left oblique one. Measured results demonstrate that the proposed antenna can achieve the CP reconfigurability in dual band, with the wide bandwidths (|S11| < −10 dB and AR < 3 dB) of 10.4% (1.55‐1.72 GHz) and 9.7% (2.29‐2.52 GHz), which cover GPS and WLAN bands.

A wideband circularly polarized (CP) dielectric resonator antenna (DRA) loaded with the partially reflective surface for gain enhancement is presented in this article. First, the DRA is excited by a microstrip line through modified stepped ring cross‐slot to generate the circular polarization. Four modified parasitic metallic plates are sequentially placed around the DRA for greatly widening the axial‐ratio bandwidth. Then, a partially reflective surface is introduced for enhancing the gain performance and further improving the CP bandwidth as well. Finally, an optimized prototype is fabricated to verify the design concept. The measured results show that the proposed DRA achieves 54.3% impedance bandwidth (VSWR<2) and 54.9% 3‐dB AR bandwidth. Besides, its average and peak gains are 10.7 dBic and 14.2 dBic, respectively. Wide CP band and high gains make the proposed DRA especially attractive for some broadband wireless applications such as satellite communication and remote sensing.

In this paper, a single-layer wideband differential-fed microstrip patch antenna (DMPA) with complementary split-ring resonators (CSRRs) loaded is proposed. First, a quarter-wave microstrip-line resonator is introduced as a capacitive coupling feeding structure which can generate a non-radiative resonant mode. Second, a set of rectangular parasitic patches is loaded co-planarly along the non-radiative edges of the DMPA. Thus, a parasitic radiative mode at the high side of the operation band is added. Meanwhile, with this arrangement, the field distribution of the DMPA has also changed, and a radiation null at high band edge is formed. Then, a pair of CSRRs is etched on the ground beneath the feeding lines, which has compensated the mismatched impedance of the DMAP at the low side of the operation band. As a result, the low-frequency bandwidth is significantly increased. Finally, the proposed antenna is fabricated and measured, and the measured results are in good agreement with the simulation ones. The measured bandwidth of the proposed antenna is ranged from 5.35 GHz to 7 GHz (about 26.7%) while keeping a low profile of 0.051λ (λ is the free-space wavelength at the center frequency) without any air gaps. Besides, the broadside gain is from 7.7 dBi to 10.7 dBi. INDEX TERMSDifferential-fed patch antenna, wideband antenna, single-layer, parasitic patches, complementary split ring resonator. YI-XUAN ZHANG (S'18) received the B.Eng. degree in electronic information engineering from Xidian University (XDU), Xi'an, China, in 2017, where he is currently pursuing the Ph.D. degree with the Department of National Key Laboratory of Antennas and Microwave Technology. His current research interests include high performance electromagnetic optimization, phased array, and 5G communication technology.