P. Sanchez-Olivares

Novel Four Cross Slot Radiator With Tuning Vias for Circularly Polarized SIW Linear Array

A substrate integrated waveguide (SIW) linear array is presented with a new circularly polarized (CP) element. The single radiator consists of four cross tilted slots. In addition, a pair of tuning metallic vias is included to improve the reflection of longest slots. A 16-element antenna prototype with -26-dB Taylor distribution and 1.5% residual power was designed, manufactured and measured to verify the new slot performance in an array configuration. A 17-dB peak gain, 1.86-dB axial ratio and 80% radiation efficiency were experimentally achieved at 17 GHz. A 3% usable bandwidth was obtained owing to frequency main beam tilt dispersion.

Linear Patch Array Over Substrate Integrated Waveguide for Ku-Band

A linearly polarized patch array with direct probe feed over substrate integrated waveguide (SIW) network (LP-PASIW) for Ku-band is presented. A double-stacked microstrip patch structure has been used as radiating elements. Internal SIW coupling patches are placed inside the SIW to obtain the desired radiation pattern. The internal coupling and external radiating patches are connected by means of copper vias. A mutual coupling model is also proposed to adjust the radiation and reflection properties of the array. An antenna prototype has been manufactured and measured. At 17.7 GHz, 16 dBi and 80% peak gain and efficiency values are obtained. Although a 10% reflection bandwidth (17-18.6 GHz) is achieved, the usable bandwidth is reduced to 3% due to array beam tilt dispersion.

Omnidirectional conformal patch antenna at S-band with 3D printed technology

This work has been supported by the Spanish Government, Ref. TEC2013-47106-C3-2-R (Project TECOAMP) and Madrid Region Government, Ref. S2013/ICE-3000 (Project SPADERADAR).

Computer Automated Design of an Irregular Slotted Waveguide Array for Ku-Band

A computer automated design methodology to synthesize a progressive wave array antenna is presented. The proposed method is based on the generalized-scattering matrix and spherical wave expansion analysis of the array. Mutual coupling effects between radiating elements are inherently considered in the design process. A linearly polarized 24-element irregular slotted array antenna at Ku-band is presented to describe the proposed computer automated design methodology. A prototype has been manufactured to experimentally validate the antenna performance. At the design frequency (17 GHz), 15.9 dB realized gain and 97% efficiency (excluding aluminum losses) values are achieved. Although the array is designed at a single frequency, it shows an overall experimental 7% usable bandwidth.

Compact Omnidirectional Conformal Array Antenna in Waveguide Technology

A conformal array antenna has been designed in the waveguide technology in order to obtain an omnidirectional radiation pattern in the azimuth plane at the Ku-band. The antenna shape is a regular prism, where the single radiating elements, which consist of a rectangular waveguide ended on a cavity–slot, are placed on the planar faces of the prism. The physical dimensions as well as the number of faces of the regular prism have been optimized following the conformal array formulation in order to achieve a minimum ripple omnidirectional pattern. An eight-faced regular prism with an apothem of 20.6xa0mm has been selected as the radiating structure. The single elements are fed by an eight-way radial waveguide power divider symmetrically excited by a 50-Ω SMA input port. The use of waveguide technology to design the single elements and the feeding network makes the conformal array suitable for low losses and high-power applications. Several prototypes have been manufactured in order to experimentally validate the antenna performance. An omnidirectional pattern with a maximum ripple of 1.6xa0dB in the azimuth plane, 95.3% efficiency, and 11.7% input matching bandwidth has been measured.

Slotted waveguide antenna design by segmented simulation and multi-objective genetic algorithm

A progressive-wave antenna automated design technique is presented in this work. By means of a simulation method based on spherical wave expansion and generalized scattering matrix, full-wave analysis of a slotted waveguide array can be efficiently performed. Since coupling effects are considered in the simulation, a final antenna design can be obtained without any further modification required on it. In order to achieve such design, a multi-objective optimization based on Nondominated Sorting Genetic Algorithm Version III (NSGA-III) state-of-the-art genetic algorithm is carried out. At the working frequency of 17 GHz, final design provides a 16.6 dBi gain, Side-Lobe Levels lower than −18.3 dB and a 0.6% power waste at the output port. A −15-dB matching bandwidth of an 8.8% is obtained. The results have been validated with commercial-software simulations.

Mechanically Reconfigurable Conformal Array Antenna Fed by Radial Waveguide Divider With Tuning Screws

A conformal array antenna with a reconfigurable radiation pattern in the azimuth plane at Ku band is presented. An eight-faced prism has been set as 3-D antenna structure. The radiating element consists of a rectangular waveguide ended on a slotted cavity. A radial waveguide network (RWGN) fed by a symmetrically placed coaxial probe has been implemented to equally feed each radiating element obtaining an omnidirectional behavior in the azimuth plane. The insertion of several metallic tuning screws (TSs) provides a reconfiguration mechanism of the electric field distribution in the RWGN and modifies the conformal array antenna amplitude feeding. Eight different configurations generating directional radiation patterns can be tuned by means of the insertion of certain TSs. In addition, the symmetrical positioning of them allows performing a main beam scanning every 45° in the azimuth plane. Several prototypes have been manufactured and measured to experimentally validate the antenna performance. A total of 65 different radiation patterns have been experimentally obtained using the proposed TSs, which provides a simple, low-loss, and low-cost reconfigurability mechanism to the presented conformal array antenna.

SIW patch array with internal coupling patches

A Substrate Integrated Waveguide (SIW) has been used to feed a progressive wave linear array of 16 double stacked patches. The amplitude and phase performance has been achieved by means of coupling patches, which are placed inside the SIW. An antenna prototype has been manufactured with a multilayer PCB structure. 16 dBi and 80 % peak gain and efficiency values at 17.7 GHz have been measured. A 10% reflection bandwidth (17 - 18.6 GHz) is achieved, although the usable bandwidth is reduced to 3% due to the typical array beam tilt dispersion of this kind of designs.