author = "Panasiewicz Junior, Jognes and Morais, D. M. S. and Pacheco, G. 
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Tecnol{\'o}gico de Aeron{\'a}utica (ITA)} and {Instituto 
                         Tecnol{\'o}gico de Aeron{\'a}utica (ITA)}",
                title = "A photonic QPSK modulator aimed at space applications",
              journal = "Progress in Electromagnetics Research Symposium",
                 year = "2015",
               volume = "2015",
                pages = "99--103",
                month = "Jan.",
             abstract = "This paper addresses the subject of the satellite payload signal 
                         transmission and the digital-microwave link. Usually, the carrier 
                         modulation data transmitter (DT) employs in-phase (I) and 
                         quadrature-phase (Q) processing to achieve phase shift keying 
                         (M-PSK). Typically, this I/Q processing is obtained by multiplying 
                         a low-frequency reference signal. Such systems usually have many 
                         stages of multipliers, amplifiers and filters. As a result the 
                         microwave transmitter is complicated, bulky and costly. The 
                         results presented are based on a photonic circuit that achieves 
                         QPSK modulation directly at the microwave frequency carrier. The 
                         QPSK modulation was performed using a carrier frequency of 2GHz 
                         and 2Mbps I/Q signal from a pattern generator using a photonic 
                         circuit with a pair of Mach-Zehnder optical modulators arranged in 
                         a parallel configuration. The source of the photonic circuit is a 
                         DFB diode laser with a wavelength equal to 1550 nm. The modulated 
                         optical signal direct detection comes from an InGaAs photo 
                         detector. The optical modulator circuit output can be directly 
                         connected to the high power amplifier (HPA) and the transmission 
                         antenna. The resulting system enables one to achieve a microwave 
                         data transmitter with a reduced mass and volume, further lowering 
                         power consumption. These achievements are very important for 
                         spacecraft engineering teams during the conception of the 
                         satellite payloads when starting a new satellite project. Gamma 
                         radiation and thermal effects of the space environment are also 
                 issn = "1559-9450",
             language = "en",
        urlaccessdate = "04 dez. 2020"