Search

This paper describes a design of dual-polarized composite patch-monopole antenna with reconfigurable radiation pattern. The design consists of a double differential-feed patch loaded with four vertical monopoles symmetrically. The monopoles are connected to or disconnected from the ground plane (GND) by changing the ON/OFF states of p-i-n diodes. By adjusting the connections between the monopoles and GND, the pattern reconfigurability (i.e., one widebeam and three narrow-beam modes) can be achieved for each polarization. The proposed antenna can switch the beam in two dimensions separately $(xz-$ and $yz-$ plane). The proposed antenna is characterized computationally and validated experimentally. The measurements result in an overlapping 10-dB return-loss bandwidth of $2.40 - 2.51$ GHz and a port-to-port isolation ≥20 dB in all the modes. In the far field, the prototype can deploy switched beam flexibility. Its radiation characteristics are confirmed by the far-field measurements, which shows the reconfigurable patterns for both polarizations.

A wideband and dual-polarized dipole antenna design technique is presented. The proposed antenna employs two sets of dipole elements in orthogonal configuration and separated by a dielectric layer. The dipole elements are excited with two separate substrate-integrated-coaxial feeds to achieve high port-to-port isolation and the overall antenna stackup is enclosed in a substrate-integrated-waveguide (SIW) cavity. To validate the proposed substrate-integrated-coaxial fed dual-polarized antenna design method, a prototype antenna was fabricated using standard multi-layer printed circuit board (PCB) manufacturing technologies to operate in the Ku-band. Measured and simulated results exhibit that the designed antenna has a wide impedance bandwidth of less than -10dB reflection coefficients at 10.28-14.8GHz and the port-to-port isolation between the two orthogonally polarized dipole antenna ports is greater than 20dB at most frequencies, making it suitable for many applications such as satellite communications. The antenna has a relatively stable gain pattern with a gain value of 5.5-6.5dBi and a low cross-polarization level (lower than 16dB) over the operating frequency range.

A novel compact and highly efficient dual-polarized horn-like antenna is presented. It exploits a radiating aperture that is fed by four smaller waveguides via a quad-furcated junction. The antenna also comprises the full feed network for the feed waveguides including an integrated 4-way orthomode power divider. Design principles are described in detail and illustrated by means of an example involving an antenna with aperture size of 2.6 $\lambda _{0} \times 2.6\lambda _{0}$ ( $\lambda _{0}$ the wavelength at the central frequency of operation) intended primarily for Geostationary Orbit (GEO) satellites. The antenna feed was designed to comply with the Additive Manufacturing rules and exhibits aperture efficiency levels close to the theoretical maximum ones over the entire transmit Ku band (10.7 – 12.75 GHz), while at the same time its profile is highly compact (6.4 $\lambda _{0}$ ). The measured results of a prototype 3D-printed in Selective Laser Melting (SLM) verified experimentally the calculated high aperture efficiency (over 90%). The total antenna feed attains return loss > 19 dB and maximum cross-polarization isolation (XPI) > 24 dB over a bandwidth of 18%. In light of the favorable electrical performances and compact size, the proposed solution constitutes an appealing alternative to profiled (or spline) horns for satellite antenna systems used either as reflector feeds or direct radiating arrays.

This work introduces an extremely low profile ( $0.4\lambda _{high}$ ) planar ultra-wideband dual-polarized reflectarray. The unit-cell structure of the array is modular in nature, and without any electrical connection between adjacent unit-cells. The array uses tightly coupled dipoles arranged in an egg-crate fashion connected with true-time-delay lines. This array provides the required phase in the highest ever reported bandwidth of 5:1 (3 to 15 GHz) with VSWR< 2.5 for a planar reflectarray. The implementation of the delay-lines is done using a sandwich configuration between two conductive planes, which significantly improves the cross-polarization purity of our reflectarray. To validate our design concept, an $18\times 18$ element ( $135\times 135$ mm) reflectarray is designed, fabricated, and measured. The measurements exhibit excellent agreement with the simulations.

A new dual-polarized antenna and array are presented for In-Band Full-Duplex (IBFD) applications, offering high inter-port isolation. The single-element antenna system consists of four H-shape slots, stacked patches for wide bandwidth, and two external hybrid couplers. The multilayer antenna is well matched from about 2.1 to 2.4 GHz and provides high isolation in this frequency range in excess of 60 dB. Two different prototypes are simulated and measured to highlight the design process. In addition, a new and compact hybrid coupler with excellent phase and magnitude stability is also presented for improved antenna radiation and IBFD performances. When compared to other similar types of hybrid coupler and antenna systems, the proposed configurations are simple to manufacture, provide a higher isolation bandwidth (10%), and higher gain of 7.3 dBi with cross-polarization levels of 30 dB or lower. The single-element design was also extended to a $2\times 2$ array and studied for different beam steering and feeding scenarios. The operating bandwidths and isolation values offered by these S-band antenna and array systems can support new data link possibilities for beam steering and future low-cost IBFD wireless networks by simple antenna fabrication.

A Ka-band dual-polarized low profile magneto-electric (ME) dipole antenna with wide operational bandwidth is proposed in this paper. A thin substrate with two-stage meandered vias is utilized for realization of the proposed antenna. The meandered vias aid in compensation of phase difference caused due to utilization of thin substrate. The thickness of proposed antenna is reduced from 0.25 λg to 0.11 λg by using these two-stage meandered vias. The low profile antenna topology results in bandwidth reduction which is neutralized by introducing asymmetric slots in the ground plane. Shorting pins are inserted for elimination of higher order TM21 mode of Ka-band that results in a uniform broadside radiation pattern due to excitation of fundamental TM10 mode. The proposed antenna covers whole Ka-band with operating frequencies from 26 - 42 GHz. A 1 × 4 antenna array is also designed and fabricated with a reasonable gain of 12.06 dBi and stable radiation patterns. Simulated and measurement results are presented with detailed justification.

The design of a low-profile wideband shared-aperture dual-polarized antenna is proposed. The proposed antenna consists of a cavity-backed slot antenna to produce vertical polarization and a slot-backed monopole antenna for horizontal polarization. The slot operates as a radiator for vertical polarization and at the same time, it works as a reflector for horizontal polarization. Two antenna prototypes are designed and simulated. The initial design has a profile of 0.28λmax, where λmax is the free space wavelength at the lowest frequency. The vertical and horizontal polarized antennas exhibit 36.1% and 39.7% bandwidths, respectively. By adding a notch in the slot, the current path increases, which reduces the operating frequency band; hence, the low-profile design is accomplished. The new version features a profile of 0.17λmax with 28.2% and 36% bandwidths for vertical and horizontal polarizations, respectively. The low-profile prototype is fabricated and measured. The measured S-parameters are consistent with the simulated one. The measured realized gain varies from 1 to 4.2 dBi for vertical polarization, while it varies from 1 to 2.5 dBi for horizontal polarization. The total efficiency of the proposed antenna is above 85% within the operating band for both polarizations. The far-field radiation pattern is measured, and a good agreement is achieved with the simulated one.