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The highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) poses a significant threat to the global swine industry. Vaccination is a preventive measure against viral infections. However, the use of vaccines in livestock healthcare programs faces the challenge of safety and delayed immune responses. Earlier studies have shown the potential of modified Bazhen powder as an immunomodulator with significant biological properties, but its effect on vaccines against HP-PRRSV is yet to be studied. This study elucidated how modified Bazhen powder could improve the safety and efficacy of the conventional PRRSV vaccine by evaluating T-cell responses, antibody levels, clinical symptoms, levels of viremia, organ health, and cytokine production. The results revealed that the oral application of modified Bazhen powder in combination with PRRS vaccination improved both cellular and humoral immunity, accelerated viremia clearance, improved lung injury scores, and reduced viral load in the tonsils. The modified Bazhen powder also effectively reduced inflammatory responses following a PRRSV challenge. These findings further highlight the pharmacological properties of modified Bazhen powder as a potential oral immunomodulatory agent that could enhance vaccine efficacy and ensure broad-spectrum protection against HP-PRRSV in pigs. [ABSTRACT FROM AUTHOR]

A multiresonance metasurface antenna for C-band application is proposed in this paper. A broadband metasurface with consistent radiation performance is designed using characteristic mode analysis (CMA). The metasurface is formed by 4 × 4 square patches, and circular slots of different radius are etched on the center and edge patches. To achieve consistent radiation, the size of circular slots on the corner patches is increased. The metasurface is excited by slot antenna, and multiple adjacent resonant frequencies are generated by combining two modes of the metasurface and resonant mode of slot antenna. The measured results show that the −10 dB impedance bandwidth of the antenna is 4.22–8.38 GHz (66%), and the peak gain is 8.2 dBi. [ABSTRACT FROM AUTHOR]

A broadband checkerboard artificial magnetic conductor (AMC) metasurface with a 61% bandwidth is proposed. Two different AMC unit cells with 180° (±37°) effective reflection phase difference over a wide frequency range from 7.3–14 GHz are designed. A checkerboard metasurface is structured with two AMC unit cells and is applied in a microstip antenna for radar cross section (RCS) reduction. The simulated results show that the antenna can achieve more than 10 dB RCS reduction from 7.2–13.1 GHz. The maximum RCS reduction is 36 dB. Meanwhile, the radiation performance of the antenna has been well kept. Finally, the low RCS antenna is manufactured and measured. The measured results are in agreement with the simulations. [ABSTRACT FROM AUTHOR]

The correction notice in the journal "Frontiers in Veterinary Science" addresses an error in the author list of an article on the efficacy and safety of a modified Bazhen powder and PRRSV modified-live virus vaccine against HP-PRRSV in piglets. Professors Chunliu Dong and Zhiyun Zhang were mistakenly excluded as corresponding authors, and the corrected author list has been provided. The authors have acknowledged the error and clarified that it does not impact the scientific conclusions of the article. [Extracted from the article]

In this paper, a compact four-element quasi-self-complementary (QSC) ultra-wideband (UWB) multiple-input multiple-output antenna with triple band-notched characteristics is proposed. Coplanar waveguides fed QSC structure is designed as radiation element to achieve wideband and small size. Besides, regular hexagonal split-ring resonators with single negative properties are designed and added on the back of the substrate to obtain high isolation in the whole operating band. Moreover, a double-fork-shaped slit is etched in each radiating element to generate three notched bands covering 3.63–4.24, 5.15–5.98, and 7.17–8 GHz. The experiment results indicate that the isolation of the proposed antenna is higher than 22 dB and the peak gain varies from 2.5 to 6.7 dB in the entire band of 3–18 GHz, which demonstrates that it is suitable for UWB applications. [ABSTRACT FROM AUTHOR]

A wideband omnidirectional dipole antenna with parasitic loop based on multi-resonant modes is proposed for WLAN, 5 G Sub-6 GHz, and RFID applications. The antenna is composed of a regular dipole with co-planar strips and a parasitic loop with four U-shaped branches. A regular dipole with co-planar strips is used to generate two resonant modes, and the parasitic loop around it generates another two resonant modes. By combining these four resonant modes, a wideband characteristic is achieved. In order to reduce the cross-polarization, four U-shaped branches are introduced, and then the cross-polarization levels are decreased from −2 dB to −13 dB. A prototype with a compact size of 0.6λ0 ×0.56λ0 ×0.012λ0 (λ0 is the wavelength in free space at center frequency) is fabricated and tested. Measurement shows that effective bandwidth is 1.8–5.6 GHz (102.7%), the measured gain variation is only 1.3 dBi, and omnidirectional radiation patterns are achieved over the operating band. [ABSTRACT FROM AUTHOR]

A compact broadband circularly polarized slot antenna for Sub‐6G applications is proposed in this article. It is composed of a broadband slot antenna exited by a Γ‐shaped microstrip feedline and an artificial magnetic conductor (AMC) reflector with a wide in‐phase reflection phase bandwidth. A unidirectional circularly polarized radiation is achieved by using the AMC reflector consisting of 6 × 6 modified Jerusalem cross unit cells. A prototype of the proposed antenna is fabricated. The impedance bandwidth and axial ratio bandwidth of the antenna is 40.78% (3.26–4.93 GHz) and 39.02% (3.3–4.9 GHz), respectively. [ABSTRACT FROM AUTHOR]

This paper demonstrates a broadband dual‐polarized metasurface antenna with high isolation and low cross‐polarization using characteristic mode analysis. A wideband metasurface with stable radiation pattern is presented by splitting the edge patches into 2 × 2 sub‐array and introducing Minkowski fractal structure in the corner patches. To achieve the dual‐polarized operation, a pair of degenerate modes of the metasurface are selected, and thus high isolation and low cross‐polarization are obtained. The metasurface is excited by two slot antennas placed orthogonally. A prototype with an overall size of 1.46 λ0 × 1.46 λ0 × 0.07 λ0 (λ0 is the free‐space wavelength at center frequency) is fabricated. The proposed antenna could achieve dual‐polarization operation. The experiment results show that the −10 dB impedance bandwidths for each port are 28.9% (4.74–6.34 GHz) and 31.4% (4.62–6.34 GHz), respectively. The isolation between the two ports is higher than 31.8 dB, and cross‐polarization level is better than −28 dB. Moreover, broadside radiation performances for two ports are obtained. [ABSTRACT FROM AUTHOR]

This paper demonstrates a broadband metasurface antenna with stable gain. A 4 × 4 square patches metasurface loaded with nonuniform hexagonal slots is proposed. To achieve stable radiation performance in broadband range, two characteristic modes with the same current direction are selected as operating modes of the metasurface. A slot antenna is employed to excite the metasurface. By combining the resonant modes of metasurface and slot antenna, the broadband is obtained. The measured results show that, the −10 dB impedance bandwidth of the proposed antenna is 4.36–8.21 GHz (61.2%), the 2 dB gain bandwidth is 4.36–7.2 GHz (49.1%), and the peak gain value reaches 10.6 dBi. [ABSTRACT FROM AUTHOR]

A low‐profile dual‐band metasurface antenna is demonstrated for 4G LTE and 5G Sub‐6GHz applications. Based on the characteristic mode analysis, a wideband metasurface with stable radiation pattern is proposed by introducing Minkowski fractal structure in the edge patches and scaling the corner patches. The metasurface is operating in Sub‐6GHz band and excited by a Vivaldi bowtie slot antenna, which also serves as the radiator in LTE band. To validate the concept, a prototype with an overall size of 1.05λ0 × 1.05λ0 × 0.045λ0 (λ0 is the free‐space wavelength at 2.3 GHz) is fabricated. The experiment results show that the −10 dB impedance bandwidths in two bands are 1.7–2.78 (48.2%) and 3.2–5.01 GHz (44.1%), respectively. Moreover, broadside radiation performances in two bands are obtained. [ABSTRACT FROM AUTHOR]

In this paper, a broadband and high-efficiency polarization conversion metasurface (PCM) is proposed. It is composed of the patch layer, two layers of dielectric substrates and the ground plane. The patch layer is formed by hexagonal patches etched with open-loop gaps. Also, the hexagonal patches are printed on the diagonal of the unit of PCM that the polarization direction of the incident wave is rotated 90°. In order to improve the efficiency of polarization conversion, two different dielectric substrates are used to achieve impedance matching between the PCM and the free space. In addition, through introducing the open-loop gap in the center of the hexagonal patch, multiple resonant frequencies are generated. Therefore, the conversion bandwidth is further expanded. Simulated and measured results show that the polarization conversion ratio (PCR) of the proposed metasurface is higher than 90% from 7.4 to 17.0 GHz. Especially, the PCR can reach 100% at the resonant frequencies. [ABSTRACT FROM AUTHOR]

A novel multibeam slot antenna using metasurface is presented in this communication. This antenna is fed by a coupling aperture and its radiating element consists of dual-layer metasurfaces formed by different units. By employing the rectangular loop slot as the coupling aperture, a wide impedance bandwidth is obtained. Meantime, a dual-layer cross-placed checkerboard metasurface is utilized to generate four beams and expand the operation bandwidth. The experimental results demonstrate that the antenna has a bandwidth of 1.37 GHz (2.18–3.55 GHz). Moreover, the four beams point at (φ, θ) = (180°, 23°), (270°, 23°), (0°, 23°), and (90°, 23°) and the maximum gain reaches 7.63 dBi. [ABSTRACT FROM AUTHOR]

In this letter, a multibeam antenna based on metasurface (MS) is proposed. By employing the partially reflecting defected MS as the radiator, taking port 1 as an example, the beam with multiple sidelobes is focused in the direction of (3°, 33°) and the peak gain increases from 6.3 to 10.57 dBi. Also, a narrow beam with half-power beamwidth of 31° is obtained in a dimension of 1.5λ0 × 1.5λ0. When the antenna is fed from different ports separately, the beams are steered in different directions. Also, through inserting the vias between two-layer patches of the MS unit, the sidelobe is suppressed and the gain is improved. The results indicate that the antenna can operate at 7.5 GHz. When four ports are separately excited, the antenna can radiate four beams pointing at (ϕ, θ) = (3°, 33°), (93°, 33°), (183°, 33°), and (273°, 33°). [ABSTRACT FROM AUTHOR]

This paper presents a compact reconfigurable ultra‐wideband antenna with multiple band‐notch characteristic. The truncated corners in the rectangular patch are employed to realize the desired ultra‐wideband (UWB) operation. The band‐notch property in the 3.5 GHz WiMAX and 5.2 GHz WLAN bands are obtained by the conventional C‐shaped slots in the radiating patch, and the band‐notch performance in the 7.5 GHz X‐band is especially realized by introducing a parasitic meandering strip beneath the ground. The reconfigurable band‐notch function is achieved by controlling the states of the PIN diodes inserted in the band‐notch structures. The overall dimension of the antenna is 19.5 mm × 14 mm. The simulation and experiment results confirm that the antenna can switch between a UWB state, three single band‐notch states, three dual band‐notch states and a triple band‐notch state. Moreover, stable radiation patterns are exhibited. [ABSTRACT FROM AUTHOR]

A 2D multibeam array antenna without beamforming network is proposed in this paper. The antenna can radiate nine beams pointing to different directions in 2D space. By etching nine U-shaped slots on the ground plane, −10-dB impedance bandwidth is improved and beam inclination angles are enlarged. The measured results show that the antenna has a −10-dB impedance bandwidth of 7.5% (from 8.16 to 8.8 GHz). The inclination angles of the scanning beams are about ±36° (in the planes of φ = 0°, 45°, and −45°) and ±30° (in the plane of φ = 90°). [ABSTRACT FROM AUTHOR]

A beam-sweeping antenna utilizing a novel active frequency-selective surface (FSS) is developed in this letter. It is comprised of a simple dipole and a cylindrical FSS formed by six columns of unit cells. The dipole used as a radiating source is situated at the center of the cylindrical FSS. The radiation pattern of the antenna could be reconfigured by controlling the states of the PIN diodes in the FSS. The dimension of the whole antenna is 0.75 λg × 0.75 λg × 1.57 λg (λg is the guided wavelength at its resonant frequency). Experimental results demonstrate that the presented beam-steering antenna can operate at 2.45 GHz and the main beam can be swept across the whole azimuth plane with a peak gain of 8.15 dBi. [ABSTRACT FROM AUTHOR]

In this paper, a compact broadband dual-polarized stacked patch antenna with the aperture coupled microstrip feed is proposed. By adding a parasitic disc patch, the bandwidth is effectively broadened. Meanwhile, to improve the isolation at the low frequency band, a rectangular slot is etched along the diagonal line of the ground plane. The measured results show that the proposed antenna can operate from 9.6 to 22.4 GHz and the relative bandwidth is 80%. Also, the isolation within the operating frequency band is better than 15 dB and the maximum gain reaches 4.08 dBi. [ABSTRACT FROM PUBLISHER]

This article presents a differential dual-band antenna-in-package (AiP) for wireless local area network applications. Dual-band operation is realized by a square ring and a pair of fork-shaped strips. For AiP, there will be an interaction between the antenna and packaged component, which usually takes place in the near field. By using two non-uniform via fences, the bandwidth at two bands is significantly improved, and the electric field in the package cavity is also effectively suppressed. The distribution of the electric field in the package cavity is analyzed, and then a method that arranges the via fences connecting the antenna ground and package ground is demonstrated. Simulation and experiment results show that the proposed AiP can operate at 2.4 and 5.2 GHz, and the relative impedance bandwidth is broadened to be 8.7 and 15.2%, respectively. Moreover, good radiation performances are achieved at two bands. [ABSTRACT FROM PUBLISHER]

In this article, a novel broadband dual-polarized antenna is proposed. It is fed by the microstrip and co-planar waveguide to realize the horizontal and vertical polarization. Its radiating element is a rectangular monopole. To broaden the bandwidth, the rectangular monopole is changed into a gradient one. Meanwhile, two symmetrical rectangular slots are etched in the ground plane. The measured results show that the bandwidths of the two ports are from 2.2 to 3.9 GHz and from 1.9 to 4.4 GHz, respectively. The corresponding impedance bandwidths are 79.4% and 55.7%, respectively. The isolation between the two input ports is better than 20 dB. The simulated result agrees well with the measured one. [ABSTRACT FROM PUBLISHER]

In this paper, the finite difference time domain model for the antenna in package is presented. The distribution of the electric field in the package cavity is analyzed, and a method that reduces the near field is proposed. By arranging via position reasonably, at most the area of the cavity electric field is uniform and decreased less than 10 dBV/m. The measured and simulated results show that the new shielding structure can decrease the electric field in the package cavity by about 10 dBV/m. [ABSTRACT FROM PUBLISHER]

A co-design method for the dual-band low-noise amplifier (LNA) and band-pass filter (BPF) is presented in this study. The dual-band BPF and LNA are designed separately by the traditional method first. In order to reduce the circuit, the dual-band matching networks (MNs) of the LNA and BPF are combined into the dual-band matching-filter. The validity is verified by a sample of 1.57/2.4 GHz LNA-filter after the co-design. The measured S21, NF and BW3 dB are 18.6 dB, 1.98 dB and 0.22 GHz at 1.57 GHz, and 15.2 dB, 1.95 dB and 0.3 GHz at 2.31 GHz, respectively. The results indicate that the co-design and cascade versions have same performance, but the co-design version cuts down the number of the passive components by nearly half. [ABSTRACT FROM AUTHOR]

A novel differential dual-band bandpass filter based on a stepped-impedance double-sided parallel-strip line is proposed in this article. In order to suppress the common-mode signal, an H-shaped ground plane is inserted. The simulated and measured results show that the proposed filter operated at 2.4 GHz and 5.8 GHz with the insertion losses of 3.2 dB and 3.5 dB, respectively. Also, the common-mode signal is suppressed to below -30 dB from 1 GHz to 7.5 GHz. [ABSTRACT FROM AUTHOR]

A miniaturized ultra‐wideband (UWB) monopole antenna with reconfigurable multiple‐band notched performance is demonstrated. By modifying the shape of the patch and the ground plane, the UWB operation is achieved. The first and second band‐notches are respectively generated by etching a rectangular slot with open ends and a U‐shaped slot in the patch, and the third band‐notch is produced by loading a C‐shaped parasitic element beneath the patch. To realize the reconfigurable band‐notched functions, four PIN diodes are inserted in three band‐rejected structures. The antenna has a compact dimension of 30 mm × 26 mm. It can switch between a UWB state and several band‐notch states by alternating the states of the diodes. Also, good radiation patterns are obtained. [ABSTRACT FROM AUTHOR]