Fabien Ferrero

Dual-band circularly polarized microstrip antenna for satellite applications

This letter presents a dual-band circularly polarized patch antenna dedicated to satellite communications. The dual-band behavior is obtained by inserting a small X-band microstrip patch antenna into a large L-band one. Both patches are printed on the same substrate and fed by electromagnetic coupling through two perpendicular slots etched in their ground planes. These slots are fed by two different 90/spl deg/ microstrip branch-line couplers printed on a stacked lower substrate. A prototype of the antenna was realized with a 1.5-mm-thick upper layer substrate and a 0.758-mm-thick feed layer substrate, both of the same dielectric material with a relative permittivity of /spl epsiv//sub r/=2.22. Simulation and measurement results are presented, showing this compact dual-band antenna achieves the required Meteosat specifications in terms of frequency bandwidth, circular polarization bandwidth, and isolation between the two communication bands.

A Novel Quad-Polarization Agile Patch Antenna

In this communication we present a novel polarization-agile microstrip antenna design. To dynamically change the polarization state, the radiating patch is fed by a tunable quasi-lumped coupler. The whole structure can be dynamically altered to radiate electromagnetic waves with vertical linear, horizontal linear, right-handed circular or left-handed circular polarization simply by changing the operating mode of the quasi-lumped coupler. Due to its topology the coupler is simply reconfigured by switching the bias of two varactor diodes via a very simple DC bias circuitry: no additional capacitors or inductors are required. A prototype is fabricated with a 0.762-mm-thick upper layer substrate for the radiating element and a 0.130-mm-thick layer substrate for the coupler circuit, both with the same dielectric material relative permittivity of 2.22. The simulated and measured scattering parameters, the axial ratio in circular radiation-mode and the cross-polarization level in linear mode, the gain and the radiation patterns are presented. The agile polarization capabilities of this new antenna, as demonstrated in this communication, underscore its suitability for modern wireless communications in a multi-path propagation environment.

A digitally modulated mm-Wave cartesian beamforming transmitter with quadrature spatial combining

With fast-growing demand for high-speed mobile communications and highly saturated spectral usage below 10GHz, mm-Wave frequency bands are emerging as the key playground for future high-data-rate wireless standards. Recent years have witnessed vast technology development on V-band (60GHz) Wireless Personal Area Networks (WPAN) and E-band (80GHz) point-to-point cellular backhauls. However, existing integrated CMOS mm-Wave solutions have relatively poor energy efficiency, especially for the transmitter (TX). This is mainly due to the use of traditional Class-A Power Amplifiers (PAs) that provide good linearity but suffer from low efficiency. In addition, the efficiency of Class-A PAs drop dramatically at power back-offs, making these transmitters even less efficient when conveying non-constant envelope signals. State-of-the-art mm-Wave Class-A PAs show less than 5% efficiency at 6dB back-off [1,2].

3D printed plastic 60 GHz lens: Enabling innovative millimeter wave antenna solution and system

During the past years, various research teams developed 60 GHz chipset solutions, using both advanced CMOS [1] and BiCMOS [2] technologies. But for the 60 GHz market to flourish not only low cost RFICs are required, low cost antennas and packages are also key elements. Recently, low cost High Density Interconnect (HDI) organic technology has been evaluated [3, 4] to develop 60 GHz module using antenna-in-package approach. Measured gain is in the order of 4 dBi but there is still a need to achieve higher gain in order to increase the transmit/receive range of the system. The use of a lens is an appealing solution since it enables to customize the system performances while using existing chipset solution. In this paper, we investigate the performances achievable by a plastic (ABS-M30) lens manufactured using low cost and rapid manufacturing 3D printing technology. Material properties at 60 GHz are reviewed, a preliminary 60 GHz lens design is detailed and the full system is validated using a WiGig wireless link (demonstrating a 10 dB improvement in the link budget in comparison with the system without lens).

Neutralized Coupling Elements for MIMO Operation in 4G Mobile Terminals

A novel multiple-input-multiple-output (MIMO) dual-antenna system covering the low LTE700 and GSM850/900 communication standards is proposed for mobile terminals. The two-port antenna system is composed of two 3-D coupling elements, placed on the vertices of the short corner of a rectangular FR4 substrate. This rectangular shape emulates the printed circuit board of a modern mobile terminal. To achieve high port-to-port isolation, the neutralization technique is applied. Simulated reflection coefficients, total efficiencies, and envelope coefficient correlation are compared to measured data showing good agreement and competitive performance.

HDI organic technology integrating built-in antennas dedicated to 60 GHz SiP solution

During past years, various research teams have been implied in the development of 60 GHz chipset solutions, using both BiCMOS and advanced CMOS technologies. But for the 60 GHz market to flourish not only low cost RFICs are required, low cost antennas and packages are also key points. So far, HTCC technology has been seen as the chosen one when targeting millimeter wave (MMW) applications. But since 60 GHz applications are targeting large volume consumer applications, the pressure on the cost of the packaging will become higher and it is highly desirable to explore alternative lower cost solutions than HTCC. In this paper, we present 60GHz integrated antennas in an innovative low cost High Density Interconnect (HDI) organic technology demonstrating promising high-gain antenna solution (>; 7 dBi).

Suitability of Ni-Zn Ferrites Ceramics With Controlled Porosity as Granular Substrates for Mobile Handset Miniaturized Antennas

Low-loss Ni-Zn porous ferrite ceramics have been obtained (porosity close to 40%) after appropriate heat treatment and shaping of nanosized powders. The key point in this process is a moderate reaction sintering that promotes desired value of porosity. Measured complex permeabilities and permittivities in the [107 Hz -1010 Hz] frequency range are presented. The developed materials show almost constant refractive index value n close to 5 up to 900 MHz. The sum of the magnetic and dielectric losses shows moderate values up to a frequency value f, unusual for spinel ferrites: tanδμ+tanδε <; 0.083 at f=600 MHz. Their efficiency for miniaturization and performances improvement of several new antennas for Digital Video Broadcasting Handheld (DVB-H) devices (frequency ranging: 470-862 MHz) are presented. High miniaturizations (about 40% to 60% when compared to not loaded antenna) are obtained. Low loss, wide bandwidth and good radiation efficiency are measured. Antennas performances are enhanced. A new antenna is also presented. Its dimensions are very small and it covers the entire DVB-H band. Suitability of Ni-Zn porous ferrites ceramics for antenna miniaturization for DVB-H applications is demonstrated.

A novel fully-automatic 3D radiation pattern measurement setup for 60 GHz probe-fed antennas

In this paper, we present a fully automatic radiation pattern measurement setup for 60 GHz probe-fed antennas. First, a detailed description of the mechanical and the RF parts of the set-up is provided with a special focus of a dedicated calibration procedure. Then, the 3D radiation pattern measurements of several antennas are presented to validate the calibration procedure and demonstrate the accuracy of the setup. The first measurement of a low-directivity monopole antenna etched on a glass substrate illustrates the usefulness of measuring probe-fed antennas instead of connector-fed antennas at 60 GHz. The second measurement of several moderate and high directivity Low Temperature Co-fired Ceramic (LTCC) patch-type antennas demonstrates the possibility to accurately measure the radiation of flip-chip mounted structures. The last example describes the radiation pattern measurement of a folded-loop antenna etched on a High-Resistivity (HR) Silicon-On-Insulator (SOI) substrate. These last technologies represent major solutions for the market of millimeter-wave antennas for W-HDMI-type communications thats why guidelines and advices are given to handle such difficult measurement with acceptable accuracy.

A New Magneto-Dielectric Material Loaded, Tunable UHF Antenna for Handheld Devices

In this letter, the impact of a magneto-dielectric resonator on a DVB-H antenna is investigated. A frequency reconfigurable antenna using a folded monopole antenna structure and varactor diodes is proposed. Two different designs are realized with and without the resonator. A measured instantaneous -6-dB bandwidth wider than 8 MHz is obtained continuously between 470 and 862 MHz for both prototypes. Design methodology is described. Measured return loss, gain, directivity, and radiation pattern are presented for different frequencies.

Feasibility Study of 4G Cellular Antennas for Eyewear Communicating Devices

A feasibility study of 4G cellular antennas operating in the LTE, GSM, DCS, PCS, and WLAN2400 standards for wirelessly connected eyewear is presented. The target bands are 700-960 MHz and 1.7-2.7 GHz. The antenna designs are capacitive coupling element types, with simple layout printed on one side of the printed circuit board (PCB) substrate. Three different antennas are examined in terms of obtainable bandwidth potential, reflection coefficient, and specific absorption rate (SAR) values considering two human-head models (SAM and Visible Human). The best antenna is -6 dB matched and has radiation efficiencies around 14% and 36% in respectively low and high frequency bands. Based on simulation data, SAR values could be above the 1-g standards.