Cookies Policy
The website need some cookies and similar means to function. If you permit us, we will use those means to collect data on your visits for aggregated statistics to improve our service. Find out More
Accept Reject
  • Menu
About
Download Photo HD

About

I am a senior researcher at the Centre of Telecommunications and Multimedia of INESC TEC, where I am also the coordinator of the area of Optical and Electronic Technologies. I received the “Licenciatura” degree in 2006 and PhD degree in 2011, both in Electrical and Computer Engineering from the Faculty of Engineering of the University of Porto. Currently I am responsible for the conception and management of R&D projects, coordination of research students and fostering the valorization of research results through new contracts with industry. I was previously involved in teaching of RF/microwave engineering and optical communications as an invited assistant professor at the University of Porto. I am author/co-author of more than 50 publications in international conferences and journals with peer-review, and 1 european patent. I have coordinated several research projects and participated in several EU research projects. My main research interests include coherent optical systems, radio-over-fibre, RF/microwave devices and antennas, and underwater wireless power/communications.

Interest
Topics
Details

Details

021
Publications

2022

Proof of Concept of a Low-Cost Beam-Steering Hybrid Reflectarray that Mixes Microstrip and Lens Elements Using Passive Demonstrators

Authors
Luo, Q; Gao, S; Hu, W; Liu, W; Pessoa, LM; Sobhy, M; Sun, YC;

Publication
IEEE COMMUNICATIONS MAGAZINE

Abstract
In this article, a proof-of-concept study on the use of a hybrid design technique to reduce the number of phase shifters of a beam-scanning reflectarray (RA) is presented. An extended hemispherical lens antenna with feeds inspired by the retrodirective array is developed as a reflecting element, and the hybrid design technique mixes the lenses with the microstrip patch elements to realize a reflecting surface. Compared to the conventional designs that only use microstrip antennas to realize a reflecting surface, given a fixed aperture size the presented design uses 25 percent fewer array elements while shows comparable beam-steering performance. As a result of using fewer elements, the number of required phase shifters or other equivalent components such as RF switches and tunable materials is reduced by 25 percent, which leads to the reduction of the overall antenna system's complexity, cost, and power consumption. To verify the design concept, two passive prototypes with a center frequency at 12.5 GHz were designed and fabricated. The reflecting surface was fabricated by using standard PCB manufacturing and the lenses were fabricated using 3D printing. Good agreement between the simulation and measurement results is obtained. The presented design concept can be extended to the design of RAs operating at different frequency bands including millimetre-wave frequencies with similar radiation performances. The presented design method is not limited to the microstrip patch reflecting elements and can also be applied to the design of the hybrid RAs with different types of reflecting elements.

2022

Optimizing Packet Reception Rates for Low Duty-Cycle BLE Relay Nodes

Authors
Paulino, N; Pessoa, LM; Branquinho, A; Almeida, R; Ferreira, I;

Publication
IEEE SENSORS JOURNAL

Abstract
In order to achieve the full potential of the Internet-of-Things, connectivity between devices should be ubiquitous and efficient. Wireless mesh networks are a critical component to achieve this ubiquitous connectivity for a wide range of services, and are composed of terminal devices (i.e., nodes), such as sensors of various types, and wall powered gateway devices, which provide further internet connectivity (e.g., via Wi-Fi). When considering large indoor areas, such as hospitals or industrial scenarios, the mesh must cover a large area, which introduces concerns regarding range and the number of gateways needed and respective wall cabling infrastructure, including data and power. Solutions for mesh networks implemented over different wireless protocols exist, like the recent Bluetooth Low Energy (BLE) 5.1. While BLE provides lower power consumption, some wall-power infrastructure may still be required. Alternatively, if some nodes are battery powered, concerns such as lifetime and packet delivery are introduced. We evaluate a scenario where the intermediate nodes of the mesh are battery powered, using a BLE relay of our own design, which acts as a range extender by forwarding packets from end-nodes to gateways. We present the relay's design and experimentally determine the packet forwarding efficiency for several scenarios and configurations. In the best case, up to 35% of the packets transmitted by 11 end-nodes can be forwarded to a gateway by a single relay under continuous operation. A battery lifetime of 1 year can be achieved with a relay duty cycle of 20%.

2021

Wide Scanning Angle Millimetre Wave 1 x 4 Planar Antenna Array on InP at 300 GHz

Authors
Hussain, B; Salgado, HM; Pessoa, LM;

Publication
APPLIED SCIENCES-BASEL

Abstract
Featured Application Short-range millimetre wave communications. The design of a uniformly spaced 1 x 4 linear antenna array using epitaxial layers of benzocyclobutene over an InP substrate is demonstrated. The array elements are conjugately matched with a uni-travelling carrier photodiode at the input. The phased array is optimised to counteract mutual coupling effects by introducing metal strips with isolated ground planes for each radiating element. The proposed antenna array can provide a gain of 10 dBi with a gain variation of +/- 3 dB. The array operates over a bandwidth of 10 GHz (295-305 GHz) with a wide scanning angle of 100 degrees in the broadside.

2021

Design and Fabrication of sub-THz Steerable Photonic Transmitter 1x4 Array for Short-Distance Wireless Links

Authors
Guerrero, LG; Graham, C; George, J; Renaud, C; George, G; Hussain, B; Salgado, HM; Pessoa, LM; Hinojosa, A; Fernandez, J; Porcel, MAG;

Publication
2021 JOINT EUROPEAN CONFERENCE ON NETWORKS AND COMMUNICATIONS & 6G SUMMIT (EUCNC/6G SUMMIT)

Abstract
In this paper we present the latest results on the design, fabrication and test of stand-alone photonic devices devoted to ultra-high bandwidth wireless access networks operating near the Terahertz (THz) band. We review the sub-THz photonics-based technology devices developed as part of the TERAPOD project, comprising the monolithically integrated Silicon Nitride photonic integrated circuit for phase distribution, the 1x4 array of integrated Uni-Travelling Carrier Photo-Diodes (UTC-PDs) and the radiative design of the high-frequency four element linear patch antenna array based on Benzocyclobutene (BCB) layers. We also report the suitability to assemble all those components in a robust small-form factor hybrid package.

2021

Evaluating a Novel Bluetooth 5.1 AoA Approach for Low-Cost Indoor Vehicle Tracking via Simulation

Authors
Paulino, N; Pessoa, LM; Branquinho, A; Goncalves, E;

Publication
2021 JOINT EUROPEAN CONFERENCE ON NETWORKS AND COMMUNICATIONS & 6G SUMMIT (EUCNC/6G SUMMIT)

Abstract
The recent Bluetooth 5.1 specification introduced the use of Angle-of-Arrival (AoA) information which enables the design of novel low-cost indoor positioning systems. Existing approaches rely on multiple fixed gateways equipped with antenna arrays, in order to determine the location of an arbitrary number of simple mobile omni-directional emitters. In this paper, we instead present an approach where mobile receivers are equipped with antenna arrays, and the fixed infrastructure is composed of battery-powered beacons. We implement a simulator to evaluate the solution using a real-world data set of AoA measurements. We evaluated the solution as a function of the number of beacons, their transmission period, and algorithmic parameters of the position estimation. Sub-meter accuracy is achievable using 1 beacon per 15 m(2) and a beacon transmission period of 500 ms.

Supervised
thesis

2021

Next Generation Long-Haul Optical Fibre Communications and Optical-Wireless Interfaces

Author
Joana dos Santos Tavares

Institution
UP-FEUP

2021

Vehicle Tracking in Warehouses via Bluetooth Beacon Angle-of-Arrival

Author
Telmo Francisco da Costa Soares

Institution
UP-FEUP

2021

Residential Consumer Behavioural Analysis on the Participation in Demand Response Strategies

Author
Kamalanathan Ganesan

Institution
UP-FEUP

2021

Constellation shaping in high-speed optical fiber communications

Author
Tiago Gonçalves Marques da Cunha

Institution
UP-FEUP

2021

Single Sideband PAM-4 Optical Transmission: design and implementation

Author
Sérgio Miguel Carvalho Gonçalves

Institution
UP-FEUP