This paper presents the design of a 10-bit second-order ΣΔ modulator with 1.2 V supply for applications with 250 kHz bandwidth to be used in the Brazilian System of Data Collection (SBCD). The modulator is implemented using an operational amplifier with a crossed-coupled input stage for gain boosting. Results presented are from simulations in TSMC 180 nm CMOS process technology on Cadence Virtuoso environment. The proposed design showed a 70.9 dB Signal-to Noise Ratio (SNR), 75.2 Spurious Free Dynamic Range (SFDR), and 11.5 Effective Number Of Bits (ENOB) with an oversampling frequency of 32 MHz.

From its emergence to the present day, traffic lights control the traffic of vehicles. However, with the increase in the number of public (bus) and private vehicles (car, motorcycle and truck), urban centers are becoming more and more populous. Such phenomenon increases environmental and noise pollution and cause congestion issues. To stem the rise of such problems, large cities are adopting the use of technological devices, approaching the concept of smart cities. Examining only the traffic management systems, several hardware and software solutions are being studied and implemented around the world. This paper aims to contribute to traffic signal systems improvement, developing a centralized traffic light controller system through the use of a wireless communication network. In order to prove the system efficacy, of most commom types of urban intersections was carried out. Direct control routines were implemented for network traffic lights, providing the whole system control for extraordinary events, such as closing roads due to accidents or public events. Finally, it has drawn up safety routines, to report to the central management the operating status of the traffic lights system lamps. With the aid of a logic analyzer connected to the outputs for each focal group,it was possible to set up a operating stages temporal diagram of each traffic light. Thus, the system validation was made based on between theoretical and practical temporal diagrams similarity.

This work presents an approach for household electricity consumption monitoring using state sensors devices (SSD) and electric load models. More specially, the state sensor circuit indicates the load states (On/Off) as well as the appliance (ID) identification number, which are stored in the cloud together with the real load power signatures acquired earlier. Based on the stored information, the proposed method estimates the average consumption per appliance and the total energy consumption. The method is based on ILM (Intrusive Load Monitoring) techniques and is suitable for on/off load types. The approach was tested for the following loads: fridge, air conditioner and microwave oven. The results show that the energy estimation from this method achieves an error lower than 10%, compared with power analyzer measurements. So, this is an interesting option to commercial smart plugs, since SSD is a cost-effective solution and can help users to save energy.

Systems involving solar energy harvesting typically need to be designed under the horizon of the energetic environmental limitations that are inserted. The objective of this work is to investigate and raise the capacity of solar energy scavening in four selected indoor environments, aiming at the applicability of energy harvesting circuits in mobile electronics or wireless sensor network, for example. For this purpose, a photovoltaic wafer cell was characterized in a controlled environment. A circuit for I-v curve extraction was developed and estimations of maximum power transfer by area were raised. The characterization results showed 14.04 % for the wafer conversion efficiency at maximum power operation point (MPP) and a respective voltage of 73 % in relation to V OC . Regarding the environments testing, location with indirect sunlight, a few hundred μWatts were captured, while in artificial illumination some tens of μW. So, using the device proposed in this paper, it was possible to quantify the energy harvesting capacity of different environments in real time.

When launching a satellite into orbit, every gram reduced from its total weight counts toward cheaper missions. With this in mind and inspired by the wide range of applications allowed by flexible electronics, this work presents the study and simulation of a leaf-like coplanar microstrip antenna on an one mil thick Kapton substrate centered in the 915MHz frequency to be used with a LoRa communication module in Low Earth Orbit (LEO) CubeSats. Ring resonators and coplanar transmission lines (CPW) were also simulated to be used in the substrate's material characterization to help understand the various challenges posed by the thin thickness. Comparing the simulations of the CPW and characteristic impedance equations found in the literature, it was possible to notice divergences between the simulated model impedance and the theoretical calculated value when dealing with the thin substrate, which indicates that the equation's models may not consider effects that appear with the reduced thickness, making it difficult to obtain a good impedance matching. The designed antenna is presented alongside a impedance matching semi flexible circuit, a coplanar waveguide, ring resonator and the study of the impedance matching hardships when using thin substrates for radio frequency applications.