Several solutions are presented to reduce the mutual coupling between two planar inverted-F antennas (PIFAs) working in close radiocommunication standards and positioned on a finite-sized ground ...plane modeling the printed circuit board (PCB) of a typical mobile phone. First, the two PIFAs are designed on separate PCBs to, respectively, operate in the DCS1800 and UMTS bands. In a second step, they are associated on the top edge of the same PCB. Realistic arrangements are then theoretically and experimentally studied. Finally, several solutions are investigated to maximize the isolation. They consist in inserting a suspended line between the PIFAs' feedings and/or shorting points. All along this paper, several prototypes are fabricated and their performances measured to validate the obtained IE3D moment method-based simulation results
In this letter, the design and measurement results of a millimeter-wave beam switching antenna are presented. Several antenna prototypes have been fabricated and measured in planar and conformal ...installations. The developed prototype consists of three antenna arrays of 16 patch elements in each array and it is operating at 61 GHz with linear polarization. A single-pole three-throw semiconductor switch is attached to the manufactured prototype using copper pillar attachment. The main beam direction of the convex antenna can be changed by switching between the antenna arrays in the prototype. Half sphere 3-D radiation pattern measurements have been performed. For the convex prototype, bent on the cylinder with radius 25 mm, beam switching with -32 ° / + 34 ° degrees is achieved.
In this Letter, the authors report the achievement of terahertz transmissions using advanced quadrature amplitude modulation (QAM)16 signals using 300 GHz silicon photonics devices, developed in ...industrial foundry process PIC25G. Up to 56 Gbps is obtained using QAM16 single channel modulation and up to 50 Gbps in a dual-channel configuration.
The design of several universal mobile telecommunications system multi-antenna systems with radiators having a high isolation, a high total efficiency and a low envelope correlation is presented. ...First, two planar inverted-F antennas, closely positioned at the top edge of a small ground plane whose size is representative of the printed circuit board of a mobile phone, are described. A technical solution is then proposed to increase the isolation between the antennas and enhance their total efficiency when still keeping them closely spaced. The technical solution is based on an optimal neutralisation technique, applied between the antennas of the structure. Several optimal systems, based on different parameters, are fabricated and measured. The envelope correlation coefficients are also computed using two different equations. In conclusion, this technique can be easily implemented at the terminal side of a wireless link and may enhance its diversity gain and multiple input multiple output performance.
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.
With the surge in mega-data communications, wireless networks are entering a revolution which has now taken off with 5G. From a user perspective, the main challenge is providing fast and agile ...connections in all usage scenarios. Considering the data-rates expected to be delivered to users (some urban areas with 1000 users per cell) the overall data collected by future base-stations will rapidly reach the Terabit/s range, translating to peak data-rates per user of around 1 Gbit/s. In this context point-to-point ultra-fast links with ultra-low latency must be enabled.
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.
This letter presents the design of a compact Planar Inverted-F Antenna (PIFA) suitable for cellular telephone applications. The quarter-wavelength antenna combines the use of a slot, shorted ...parasitic patches and capacitive loads to achieve multiband operation. The commercial electromagnetic software IE3D is used to design and optimize the structure. The resulting antenna can operate from 880 to 960 MHz and 1710 to 2170 MHz covering GSM, DCS, PCS, and UMTS standards with a VSWR better than 2.5. Good agreement is found between simulated and measured results.
A novel internal planar inverted-F antenna (PIFA) suitable for handset terminals is presented. The structure combines shorted parasitic patches, capacitive loads and slots to achieve multiband ...operation. This compact antenna operates in the GSM, DCS, PCS, UMTS, HIPERLAN/2 and IEEE 802.11a bands within 2.5:1 voltage standing wave ratio (VSWR) and with good efficiency.
In this letter, a novel port-to-port isolation technique suitable for a two-antenna system positioned at the top corner of a mobile phone is presented. The chosen planar inverted-F antennas (PIFAs) ...are intended to operate in the UMTS band 1.92-2.17 GHz and more precisely in the UMTS Rx band for diversity purpose. First, the distance between the PIFAs is severely reduced to 4 mm (0.027 lambda 0 ) in order to obtain a very compact system. This proximal placement causes an increase of the insertion loss between the feeding ports of the PIFAs and therefore degrades the overall diversity performance of the two-antenna system. To compensate for this effect, the neutralization technique previously proposed by the same authors is implemented. Then, a novel way to implement this technique is studied to further improve the PIFAs' port-to-port isolation. It consists in achieving the neutralization of the antennas trough folded lines connected to the printed circuit board (PCB). A new prototype is fabricated and measured. The S-parameters and the total efficiency are presented. Additionally, the most important diversity metrics are computed to evaluate the potential of this novel two-antenna system for diversity applications in the UMTS Rx mode.
