Artificial material has the feature to realize a controllable effective permittivity, which leads to many potential applications in the RF and optical fields. In this study, an artificial material is proposed for a Resonant Cavity antenna (RCA) to enhance the gain of patch antenna. The artificial material is made of a lot of circular conducting patches in a uniform size hosted in an FR-4 substrate. The fabricated artificial material is in a square shape with a length and width of 52 mm × 52 mm and a thickness of 1.2 mm. The artificial material is set in front of a patch antenna to construct an RCA, and the gain property of the proposed RCA is evaluated with the simulation and measurement methods. The results by both the simulation and measurement methods prove that the gain is enhanced by the proposed artificial material. The maximum gains are 14.5 dBi in simulation and 12.8 dBi in measurement at 15 GHz for the RCA with on slab of the artificial material. The gain is improved compared to the gain of a patch antenna without the artificial material.
A low-profile half-mode substrate integrated waveguide (HMSIW) filtering antenna with high frequency selectivity is proposed in this letter. The proposed antenna with a height of 0.014λ0 (λ0 is the free-space wavelength) consists of a slot-loaded HMSIW cavity, two parasitic patches, and five shorting pins. An upper-edge radiation null is generated by the interaction between the HMSIW cavity and parasitic patches. A rectangular slot etched on the HMSIW cavity is adopted to generate another null to improve the filtering performances at the upper stopband. Besides, the radiation in the lower stopband is suppressed by two nulls which emerge due to placing shorting pins under two parasitic patches. Thus, four radiation nulls can be obtained to enhance the frequency selectivity. The measured results illustrate that the proposed antenna provides an impedance bandwidth of 4.3% ranging from 2.74 to 2.86 GHz and a peak gain of 6.76 dBi during the operating frequency band. Moreover, four radiation nulls appear at 2.34, 2.56, 3, and 3.24 GHz in the lower and upper stopbands.
In this work, a diversity antenna with a high level of isolation is presented in this paper. To make the antenna compact, the radiating parts are arranged on opposing sides of the substrate. The isolation between the ports is sufficient for the use of a MIMO system, which is achieved through the orthogonal positioning of radiating elements. Wideband and narrowband antennas are placed on opposite sides of the substrate. The suggested monopole antenna has an impedance bandwidth of 3.1 GHz to 14.9 GHz, whereas the rectangular narrowband antenna has an impedance bandwidth of 5.4 GHz to 5.62 GHz. More than 16 dB of isolation exists between the two ports. The proposed antenna has a maximum gain of 2.9 dB. The diversity nature of the proposed MIMO antenna is studied in terms of Envelope Correlation Coefficient (ECC), Diversity Gain (DG), and Total Active Reflection Coefficient (TARC).
In this paper, a design method of spaceborne multi-beam antenna array is proposed. Multi-beam is achieved by rotating subarrays. A high efficiency circularly polarized horn antenna array working in Ka band is designed and processed. The antenna array has 16 large axial ratio elliptical beams, which can achieve the beam coverage range of 53°×49.1°. The simulation results are basically consistent with the test results, verifying the effectiveness of the proposed method. The design method of multi-beam antenna proposed in this paper can meet the requirements of multi-beam seamless coverage.
This letter presents a low-cost dual-band circularly polarized microstrip antenna for GNSS applications. The dual-band operation is achieved by stacking two metallic patches on a conventional FR4 substrate. The designed antenna can cover GPS L1 band, BeiDou B1 band, Galileo E1, E5b bands, and GLONASS G1, G3 bands, through a bandwidth of 1.118 GHz-1.215 GHz in lower L band and a bandwidth of 1.55 GHz-1.61 GHz in the upper L band. In order to achieve a wide axial ratio bandwidth, a dual-feed mechanism utilizing a capacitively coupled probe feeding scheme is incorporated. The overall size of the proposed antenna is 100 mm by 100 mm. The measured results indicate an excellent correlation with simulations.
This paper introduces a novel planar super-wideband (SWB) antenna with reconfigurable band-notch characteristic. The antenna can work in band-notch mode or band-notch free mode. A good impedance matching is responsible for the SWB characteristic of the proposed antenna by adopting a gradient ground, a gradient feeder line, and a gradient radiating patch. Furthermore, to achieve a reconfigurable notched band function, a 0.3 mm deep slot which is 16 mm in length and 8 mm in width is dug near the antenna feeder for the placement of dielectric plates etched with different sizes of split ring resonator (SRR). The designed antenna has a size of 200 mm × 109 mm × 0.79 mm, and the measured frequency band of bandwidth covers 0.8-26 GHz with a reconfigurable band-rejection characteristic. The dielectric plates with different SRRs reject the part of WLAN band (5.44-5.55 GHz), X-band satellite downlink band (7.65 GHz-7.82 GHz), and 6.33 GHz-6.59 GHz. A good agreement is achieved within the super-wideband frequency range between simulated and measured results.