Antenna is excited with equal amplitude, however, in order to obtain a right-handed circularly polarized wave, 0 °, -90 °, -180 °, and -270 is excited with a relative phase difference °, 4 single It provided with the element. Each element includes a vertical portion and a horizontal portion. RF trap filter, so as to provide a desirable gain to cover all frequency bands three modern GPS system, are arranged in a horizontal portion. Furthermore, the antenna comprises a high-frequency trap filter exhibiting high impedance for one of the three frequency bands.

Triple band gps trap Loaded Inverted l antenna array

In this communication, we have proposed a nonuniform series-fed angled dipole array antenna with a high gain, a wide bandwidth, a good sidelobe level (SLL), and a high front-to-back ratio characteristics. The proposed array antenna structure consisted of eight dipole elements, and each dipole was connected to a parallel stripline printed on the front and back sides of the substrate. From the first dipole element near the ground plane to the eighth dipole element at the end of the parallel stripline, the length of each dipole was reduced by $\Delta L_{d}$ . As with dipole length, the spacing between the dipole elements decreased by $\Delta S_{d}$ from each previous dipole spacing. Compared to uniform array antennas, the impedance and gain bandwidths were greatly increased, and the SLL and front-to-back (F/B) ratio characteristics were improved. The proposed array antenna had an $\vert S_{11}\vert dB, an impedance bandwidth of 23.3–51.0 GHz, and a 3 dB gain bandwidth of 22.0–44.0 GHz. At 28 GHz, the E- and H-plane SLLs of the proposed array antenna were −24.1 and −18.8 dB, respectively. The F/B ratio of the proposed antenna was less than −30 dB.

A High-Gain and Wideband Series-Fed Angled Printed Dipole Array Antenna

In this communication, a dual-mode compression method is proposed for wideband applications of thin dipole antennas. In this method, only two points along the thin dipole antenna are properly found and loaded by two capacitors, lumped or distributed. At these two loading points, there are current nulls of the third mode of the dipole. With two capacitive loadings, an obvious upshifting of the first mode’s resonant frequency is observed but with little effects on the third mode. By compressing the first and third modes, an enhancement of the antenna bandwidth is achieved. In addition, a parallel line is used as a transformer for impedance matching. A prototype of the design has been fabricated and tested. The measured results agree well with the simulated ones. In the thin structure of $1.01\times 0.09\,\,\lambda _{0}$ ( $\lambda _{0}$ is the free space wavelength at the center frequency), a wide bandwidth from 1.88 to 3.18 GHz (51.4%) is achieved, performing an omnidirectional radiation pattern with gain of 2.0–4.0 dBi in azimuthal plane.

Mode Compression Method for Wideband Dipole Antenna by Dual-Point Capacitive Loadings

A dual-mode compressed high-order-mode dipole loaded with bent stubs is presented for sidelobe suppression. When the high-order modes are introduced to achieve high gain, the sidelobes are generated due to the reverse currents along the dipole. To suppress the sidelobes, the bent stubs are used to impair the reverse currents. By bending the stubs, the sidelobe level (SLL) is decreased by 12 dB, on average. A prototype is fabricated and measured to validate the principles. The measurements show that the gains are higher than 4.4 dBi over the entire operating band of 3.26–4.075 GHz (22.2%). Within the desired n 78-band (3.3–3.8 GHz), the measured radiation patterns are consistent with simulations, and the suppressed SLL is less than −10 dB.

Sidelobe Suppression of Dual-Mode Compressed High-Order-Mode Dipole by Loading Bent Stubs

A 3D printed, low-profile, electrically small antenna with a quasi-isotropic radiation pattern is presented herein. It is composed of an electric meandered dipole antenna, and the extended arcs from the meander line mimicking the current flow of the loop antenna. A quasi-isotropic radiation pattern is achieved from the total current flow over the proposed structure. Modern stereolithographic 3D printing and nano-polycrystalline copper coating technologies are used to build a prototype. The measured antenna exhibits a good uniformity in terms of the radiation pattern with a maximum gain deviation of 4.5 dB at 959 MHz and a radiation efficiency of 81 %, close to the computed expectations. The electrical size of the antenna ka is 0.48, and its height is $\lambda _{0}$ /82.32.

Realization of Electrically Small, Low-Profile Quasi-Isotropic Antenna Using 3D Printing Technology

A broadband, low-profile, compact, and cost-effective antenna consisting of a printed dipole loaded with split-ring resonators (SRRs) is presented. The antenna consists of two identical printed SRRs, each enclosing an arm of a printed dipole element. Each SRR and the center-fed half-wavelength dipole element are printed on the top and bottom sides of a thin dielectric substrate. The dipole is excited by a coaxial feed, while the SRRs are electromagnetically coupled to the dipole. The dipole, in conjunction with the SRRs, generates three resonant modes with stable omnidirectional radiation patterns. These resonances interact to provide broadband characteristics, that is, a measured impedance bandwidth covering 1.32–2.46 GHz for a reflection coefficient of less than −10 dB. The functionalities, mechanisms, and modes of operation of the composite antenna structure are discussed in relation to both the dipole and the SRRs. A prototype is fabricated and measured in order to validate the antenna design. It is computationally and experimentally confirmed that the antenna demonstrates broadband characteristics as well as a stable gain with non-deteriorating omnidirectional radiation patterns. The compact antenna, which has the overall dimensions of 9.6 mm $\times$ 74.4 mm $\times$ 0.508 mm ( $0.06\lambda \times 0.469\lambda \times 0.0032\lambda$ at 1.895 GHz), has a measured fractional bandwidth of 60.31%, an omnidirectional radiation pattern with a gain greater than 1.8 dBi, and a radiation efficiency greater than 88% within a broad impedance bandwidth. The compact size, simple structure, and stable radiation properties of the antenna render it suitable for many wireless communication applications.

Compact Broadband Omnidirectional Radiation Pattern Printed Dipole Antenna Incorporated With Split-Ring Resonators

This article proposes two reduced-size crossed-dipole antennas that comprise two printed crossed-dipole arms and a pair of vacant-quarter printed rings to generate circularly polarized (CP) radiation The T-shaped crossed-dipole antenna is similar to a conventional crossed-dipole antenna but differs that half of the crossed dipole is rotated 90° This rotation reduces the dipole’s area coverage by nearly half, resulting in a compact antenna that generates CP radiation with performance similar to that of a conventional crossed-dipole antenna A compact folded E-shaped crossed dipole with good CP radiation characteristics is formed by folding the arms of the T-shaped antenna The performance of these compact reduced-size crossed-dipole antennas is discussed The T-shaped antenna with an overall radiator size of 303 $\text {mm} \times 514\,\,\text {mm} \times 0508$ mm (029 $\lambda _{o} \times 05\lambda _{o} \times 0005\lambda _{o}$ at 297 GHz) has an $\vert \text {S}_{11} \vert dB bandwidth of 258–342 GHz (28%) and a 3 dB AR bandwidth of 278–316 GHz (128%) The folded E-shaped crossed-dipole antenna with overall dimensions of 196 $\text {mm} \times 31\,\,\text {mm} \times 0508$ mm ( $021\lambda _{o} \times 033\lambda _{o} \times 00055\lambda _{o}$ at 325 GHz) has an $\vert \text{S}_{11} \vert dB bandwidth of 292–344 GHz (164%) and a 3 dB AR bandwidth of 306–344 GHz (117%)

Design of a Reduced-Size Crossed-Dipole Antenna

This paper presents a compact low-profile slot antenna integrated with a photovoltaic cell. The photovoltaic cell consists of a top metal grid, gallium arsenide substrate, and metallic bottom contact. The metallic bottom contact was used as a ground plane where the slot was etched for resonance. A second substrate was placed under the ground plane, and a 50 Ω microstrip line was printed on its bottom side to excite the slot. A chip inductor was used as a radio frequency (RF) choke in the alternating current blocking circuit to suppress RF current leakage towards the photovoltaic cell. Hence, the proposed antenna has a unique feature of functioning simultaneously as a photovoltaic cell and an antenna. The overall dimensions––25 mm × 31.75 mm × 0.893 mm (0.48λo × 0.61λo × 0.017λo at 5.77 GHz)––of the photovoltaic cell-integrated slot antenna structure can be used effectively with Internet of Things devices.

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Compact Slot Antenna Integrated with a Photovoltaic Cell

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Heesu Wang

Papers

A High-Gain and Wideband Series-Fed Angled Printed Dipole Array Antenna

Compact Broadband Omnidirectional Radiation Pattern Printed Dipole Antenna Incorporated With Split-Ring Resonators

Design of a Reduced-Size Crossed-Dipole Antenna

Compact Slot Antenna Integrated with a Photovoltaic Cell

Coplanar Waveguide-Fed Bidirectional Same-Sense Circularly Polarized Metasurface-Based Antenna