Daniel Segovia-Vargas

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Unique properties exhibited by metamaterial transmission lines have been previously used to design a large number of dual-band microwave passive devices, but not active ones. In this paper, a novel dual-band active filter scheme based on composite right/left-handed transmission lines is proposed. The inclusion of these types of lines as feedback sections in(More)
In this paper, differential low-noise amplifiers are presented as a very powerful solution for radio astronomy applications. A fully differential amplifier topology has been analyzed and implemented in microstrip technology with discrete surface mount components. The amplifier design is made for an active receiving dense antenna array. Thus, the(More)
In this study, the use of dual-composite right-left-handed (D-CRLH) transmission lines is proposed for the design of diplexers. The D-CRLH diplexers present advantages over conventional diplexers such as smaller size (especially in the ultra high frequency band). The design procedure and the design equations are presented in this paper. The non-linear phase(More)
The active integrated antenna (AIA) concept has been applied to design a broadband receiver front-end. A design procedure for active broadband patch antennas based on resistive equalization is presented. The use of the AIA has allowed the design of efficient RF front-ends by increasing its effective gain, noise figure, and merit . In addition to improving(More)
Differential amplifiers can be an appropriate solution in the implementation of radio astronomy receivers, due to their efficient interference and harmonic isolation. In this paper, two different topologies are presented. The first one consists of two single ended amplifiers in a balanced topology. The second one is formed by cascading two simple(More)
This manuscript proposes the combination of several photomixing THz sources for overcoming the power limitations of this technology. Each element is placed in the gap of a balanced antenna. All the elements conform a 2D rectangular array. For avoiding issues related to having out-of-focus sources when using one electrically large silicon lens, two different(More)
This paper presents a full duplex active RF identification system with arbitrary values for any of the two frequencies in the different radio links. First, the antennas proposed in this paper are based on linearly polarized self-diplexed patch antennas working in a full-duplex way at 2.45 GHz for the reader-transponder (or tag) link and at a lower variable(More)
This paper analyzes the noise and gain measurement of microwave differential amplifiers using two passive baluns. A general model of the baluns is considered, including potential losses and phase/amplitude unbalances. This analysis allows de-embedding the actual gain and noise performance of the isolated amplifier by using single-ended measurements of the(More)
In this paper, a proof-of-concept sub-THz detector for its use in radio telescopes is presented. The detector is intended to work at room-temperature and to be suitable for cosmic microwave background B-mode polarization measurements, so a high sensitivity photon-countig receiver is required. The proposed detector is a practical arrangement of several(More)