We present here the design and the optimization of a dual-band dual linearly-polarized transmitarray antenna with a 1-bit phase resolution (i.e. two phase states with 180° of relative phase-shift). The antenna operates in both downlink and uplink K/Ka-bands (17 -21 GHz for the lower frequency band, and 27 -31 GHz for the upper one) and could be used for satellite communication applications. In order to implement dual-band and dual-polarization, the unit-cell consists of four orthogonal superposed U-slotted patch antennas interconnected by a metallized via hole. A 2020 transmitarray based on the proposed unit-cell architecture has been optimized by using our in-house tool and validated through full-wave electromagnetic simulations. The 55 mm² unit-cell size allows beam scanning over large field of view (up to 80 deg.). A maximum gain of 23.4 and 21.4 dBi has been achieved at 29.1 GHz and 19.5 GHz, respectively. The gain 1-dB bandwidth is equal to 17.4% and 10.5% at the lower and the upper frequency bands, respectively.

We propose here a 4040-element sharedaperture dual-band dual linearly-polarized transmitarray with 1-bit phase resolution and fixed beam at Ka-band. The design is based on a stacked approach where the unit-cell size is compact and is equal to only 0.48×0 and 0.32×0 at 29 GHz and 19 GHz, respectively. The beam-scanning performances of this array are compared to those of an array with the same number of elements and same illumination but comprising unit-cells based on the interleaving approach (lattice size of 0.72×0 and 0.47×0, respectively). The shared-aperture unitcells include four printed U-slotted patch antennas and a connecting metallized via; the desired 180° phase shift is obtained by rotating one of the patches around its corresponding via. Our simulation results demonstrate that the transmitarray based on the stacked approach exhibits excellent beam scanning performance up to ± 70° on the two bands. A prototype pointing at broadside has been optimized and fabricated to validate the numerical simulations.

In this paper, we present a method to design a switchable polarizer using p-i-n diodes. An antenna-filterantenna architecture with four metal layers (receiving and transmitting radiating elements, ground plane, and bias lines) is implemented to convert an impinging linearly-polarized electromagnetic wave to a circularly-polarized one. Furthermore, by controlling opportunely the bias current flowing on the two pi-n diodes flip chipped on the transmitting radiating element, the transmission wave can be switched to either left-handed circular polarization (LHCP) or right-handed circular polarization (RHCP). Full-wave electromagnetic simulations of a single element show a transmission loss < 0.8 dB for both polarization (LHCP/RHCP) and 180° phase difference in the frequency band (27 -31 GHz).

This paper presents transmitarray-based antenna solutions for SATCOM transmit (Tx) user terminals at Ka-band. We propose a new electronically-reconfigurable unit-cell structure which combines a 2-bit phase control with circular polarization agility. Six p-i-n diodes are integrated into the proposed unit-cell implemented by stacking two halfwavelength periodic structures: a reconfigurable phase-shift module and a switchable linear-to-circular polarization converter. The two structures, developed on a standard PCB stack-up, are separated by an optimized air gap. A 576-element square transmitarray with 3456 integrated p-i-n diodes has been designed, optimized, and fabricated. To enhance the advantages of this innovative architecture, its performance is compared to the one of our previous transmitarray demonstration based on a random sequential combination of 576 vertically-and horizontally-polarized 2-bit reconfigurable unit-cells. To the best of our knowledge, this represents the first demonstration of transmitarray with two stacked reconfigurable functionalities.