Tobias Chaloun

Design and Analysis of a Reflectarray Using Slot Antenna Elements for Ka-band SatCom

This paper presents a folded reflectarray designed for Ka-band satellite communication applications. The array element is a dual-polarized slot antenna with multilayered PCB structure and is designed to operate at 29.5-30.8 GHz band for both transmitting and receiving with single linear polarization. Vias are employed to suppress the surface wave propagation and reduce the mutual coupling between adjacent array elements, for achieving a reflectarray with a wide scan angle range. An equivalent circuit model for the array element is developed and it agrees well with the EM simulation results. Several passive demonstrators consisting of 116 elements spaced by 0.5λ30GHz were fabricated and measured. The experimental results show that the presented reflectarray is capable of steering the beam up to ±60° in both Eand H-planes with low cross-polarization level.

Antenna array elements for Ka-band satellite communication on the move

Two dual-polarised reflectarray unit cells for the folded reflectarray and one linearly polarized array element for direct radiating array for Ka-band SatCom on the move are presented in this paper. All of these antenna unit cells have multi-layered structure and are designed for the smart array antenna with beams that can be steered to large scanning angles. The unit cells for reflectarray are designed to operate at 29.5-30.8GHz band for both transmitting and receiving while the antenna element for the direct radiating array is designed to have a dual band operation: 29.5-30.8GHz for transmitting and 19.7-21.0GHz for receiving. These three antenna elements have a low profile and the simulation results show that they exhibit good radiation performance over the required frequency bands.

Active transmitarray submodule for K/Ka Band Satcom applications

A novel concept for an active transmitarray architecture for K/Ka Band Satcom applications is presented. The highly-integrated antenna system is based on planar multilayer arrangement covering both Satcom frequency bands for uplink at 30 GHz and downlink at 20 GHz. To verify the proposed manifold approach, the individual components and a first active dual-band transmitarray submodule enhanced by a multi-functional SiGe BiCMOS MMIC have been realized and measured successfully.

Design of a Dual-Polarized Stacked Patch Antenna for Wide-Angle Scanning Reflectarrays

A novel dual-polarized stacked patch antenna element for wide-angle scanning satcom on the move applications at Ka-band is presented. The proposed highly integrated multilayer unit cell element operates from 27.8 to 30.8 GHz with excellent scan performance up to ±60° in both E- and H-planes. High port-to-port isolation in the entire scan volume evidences the antennas distinguished suitability for integration into an active folded reflectarray transceiver architecture. Parasitic effects in planar array antennas degrading the intended scan volume are investigated using the infinite array analysis, and measures are introduced to suppress them efficiently. To validate the proposed antenna design, several configurations were fabricated and measured successfully. The experimental results show close agreement with the simulations and indicate its excellent scanning capabilities.

A planar, scalable active transceiver array for mobile Satcom applications

A novel concept of scalable planar transceiver arrays for Satcom on the move applications is presented with emphasis on the highly integrated combination of antennas and an innovative SiGe BiCMOS technology enhanced by the monolithic integration of RF-MEMS switches.

0.25µm BiCMOS system-on-chip with four transceivers for Ka-band active reflectarrays

A highly complex mm-wave system-on-chip (SOC) for Ka-band active antenna arrays is presented, containing digital and mixed-signal circuits, RF-MEMS switches and four transceivers. In RX mode, 13.7dB of maximum gain with -21dBm IP1dB were obtained, in TX mode, 11dB of maximum gain with -2dBm OP1dB. A total of 65536 amplitude and phase states can be set. The IC has a total power consumption of 222mW in RX and 337mW in TX mode and occupies 4×3.85mm2.

Enhancing angle estimation for off-boresight targets using biomimetic antenna arrays

Biomimetic Antenna Arrays (BMAAs) are able to enhance the angle estimation of miniaturized radar sensors by mimicking the hearing system of a fly. This technique has significant advantages over conventional approaches when only limited space is available. While recent works show the enhancement for targets in the vicinity of the boresight direction only, this work presents a more generalized design methodology to enhance the angle estimation for off-boresight targets. Radar measurements of a realized BMAA have been conducted and show a significant increase in angle estimation capability compared to a conventional antenna array at a target angle of 20 degrees,

Enhanced angle estimation accuracy of ultra compact radars inspired by a biomimetic approach

The theoretical and experimental evaluation of using biomimetic antenna arrays (BMAAs) in an angle sensing radar system is presented. This ultra compact antenna system can enhance the angle estimation accuracy for radar systems which allow only small antenna separations due to the limited available space. A quality criterion will be given to indicate which BMAA parameters are necessary to achieve precise angle estimation accuracy. Radar measurements show a reduction in the RMS angle estimation error by a factor of 2 compared to conventional antenna systems of the same size.

3D transition between thin and thick waveguides to interconnect chip and antenna-in-package

It is very challenging to efficiently radiate millimeter-wave signals from silicon chips, especially from standard CMOS chips which use low-resistivity lossy silicon substrates. To address this issue, this paper describes a novel 3D transition which efficiently couples an on-chip signal and then directly feeds an in-package antenna. To verify this idea with low cost, a transition between thin and thick waveguides is studied using printed circuit boards. This transition features an insertion loss of 1.4 dB at 77 GHz and a 15-dB return-loss bandwidth of 6 GHz. Furthermore, this transition is inherently integrated to feed a hollow horn, and the whole antenna achieves more than 10 dBi gain from 74.9 to 79.3 GHz.