I. F. da Costa

Optically controlled E-antenna for cognitive and adaptive radio over fiber systems

This work describes the development of an optically controlled reconfigurable E-antenna for cognitive and adaptive radio communications systems at 2.4 and 5.8 GHz ISM bands. Numerical simulations and experiments demonstrate the antenna frequency response can be efficiently adapted in the optical domain over two different frequency bands.

Photonic downconversion and optically controlled reconfigurable antennas in mm-waves wireless networks

We report on optically controlled antennas and photonic downconversion for mm-wave wireless communication applications. Experimental results demonstrate a transmission of 1.25 Gb/s using 28 and 38GHz frequency bands.

Dual-use system combining simultaneous active radar & communication, based on a single photonics-assisted transceiver

This paper report on the development and field trial of a dual-band and dual-use system based on a single photonics-based transceiver and a single radiating element, able to simultaneously carry out radar and communication functionalities. The coexistence of the two operations does not introduce any penalty on the system performance. The innovative sharing of both transceiver and antenna element allows for a reduction in terms of cost and Size Weight and Power consumption. The dual-use radar-communication system has been demonstrated in a outdoor field trial combining a radar experiment in S-band and C-band OFDM (Orthogonal Frequency Division Multiplexing) communication.

Frequency-agile E-shaped printed antenna for millimeter waves applications

This article describes the development of a low profile and frequency-agile printed antenna for millimeter waves applications. The antenna structure is based on an E-shaped slot fed by a printed probe. Proper managing the probe length in order to reconfigure the antenna impedance matching ensures the frequency-agile functionality. Experimental results demonstrate the proposed antenna provides four different configurations of frequency response from 27 to 40GHz. The measured antenna gain varies from 7.5 to 8.9dBi.

Dual-band slotted waveguide antenna array for communication, maritime navigation and surveillance radar

This paper describes the development of a dualband slotted waveguide antenna for communication, navigation and surveillance radar applications. Two different slot sizes on opposite faces are designed for enabling antenna operation over two different frequency bands. In this way, it becomes possible to perform diverse sorts of tracking using a unique structure. Numerical results, obtained using ANSYS HFSS, demonstrate the proposed antenna provides two bandwidths of approximately 15% and 6.5% for S-band and C-band, respectively. The antenna gain varies from 12.7dBi at 2.2 GHz to 16.37dBi at 4.6GHz.

A dual-band slotted waveguide antenna array for radars applications

This paper describes the design and fabrication of a novel dual-band slotted waveguide antenna array for radar applications. The radiation structure is composed by two groups of slots, milled into the rectangular waveguide in opposite faces, enabling the antenna operation over two different frequency bands. Using this innovative structure becomes possible to perform diverse sorts of tracking using a unique structure for different radar applications, such as maritime navigation, surveillance and communications. Numerical results were obtained by ANSYS HFSS and measurements demonstrate two operational bandwidths over the S- and C-frequency bands. The antenna gain varies from 14.41dBi to 17.64dBi at 2.25GHz and 4.91GHz, respectively.