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Product Development
Published in Saad Z. Asif, 5G Mobile Communications Concepts and Technologies, 2018
A base station accommodates multiple RF modules to support different radio technologies. An RF module is a multi-carrier, multi-standard radio transceiver unit for processing radio frequency signals. It could have three or more independent branches to transmit and receive signals (i.e., sectorization). RF and system modules can be housed in the same rack / cabinet. When RF module is placed on the tower mast it is called as RRU (Remote Radio Unit). The RRU is the radio frequency part of a distributed base station and is installed near antennas (on tower masts). The RRU modulates, demodulates, combines, and divides baseband and RF signals similar to an RF unit.
Internet of Things-Based Speed and Direction Control of Four-Quadrant DC Motor
Published in Lavanya Sharma, Pradeep K Garg, From Visual Surveillance to Internet of Things, 2019
Bhupesh Kumar Singh, Vijay Kumar Tayal
A switch control is used to give inputs to the MCU for speed control. The MCU works on a specified coding and gives the output that is fed to the encoder. The encoder converts the input to desired output, and the output of the encoder is sent to the RF module. The RF module sends a signal of radio frequency to the receiver section.
Highly Integrated Ultra-Low Power RF Transceivers for Wireless Sensor Networks
Published in Christian Piguet, Low-Power Processors and Systems on Chips, 2018
Brian P. Otis, Yuen Hui Chee, Richard Lu, Nathan M. Pletcher, Jan M. Rabaey, Gambini Simone
If we assume a power budget of 100 μW and the RF module is allotted 20% of this power budget, at a 1% radio duty cycle, this provides the on-state power consumption goal of 2 mW for the entire RF transceiver.
Localization strategies for robotic endoscopic capsules: a review
Published in Expert Review of Medical Devices, 2019
Federico Bianchi, Antonino Masaracchia, Erfan Shojaei Barjuei, Arianna Menciassi, Alberto Arezzo, Anastasios Koulaouzidis, Danail Stoyanov, Paolo Dario, Gastone Ciuti
An alternative way to generate a variable magnetic field consists in applying an angular rotation to an EPM (rotating permanent magnet – RPM) with the aim of propelling a spiral-shape capsule through its rotation, as shown in Figure 1(f). Intensive studies on how exploiting this approach for endoscopic capsule actuation and pose estimation were conducted by J.J. Abbott and colleagues between 2013 and 2018 [43–47]. Authors designed a WCE with a helical-shape structure and internally embedding: (i) an IPM for locomotion; (ii) six Hall-effect sensors for localization; and (iii) an RF module for data communication. The teleoperated control of the capsule was guaranteed through a six DoFs robotic arm (Yaskawa, Motoman MH5, Japan) with an appropriately designed end-effector (seven DoFs) equipped with a Maxon 24V DC-motor and a NdFeB grade-N42 cylindrical diametrically magnetized EPM (25.4 mm in diameter and 25.4 mm in length). Authors imposed an angular rotation of the EPM to generate a variable rotating magnetic field, exploited for the propulsion of the WCE. First, the authors derived in [43,44] a mathematical model, based on the magnetic dipole assumption, to describe how the rotating magnetic field is distributed over the operative workspace and how this magnetic distribution can be properly exploited to obtain the endoscopic capsule propulsion. As reported by the authors, it is fundamental to know the capsule pose in order to obtain desired and safe capsule propulsion. To solve this issue, authors then proposed and validated in [45,47] a novel approach to estimate position and orientation of a capsule actuated through an RPM. For this scope, the previous developed mathematical model was improved in order to derive the magnetic field magnitude perceived by the capsule as function of the relative angle θ. between the RPM and the capsule rotation axis. Once this dependence was derived, authors elaborated an algorithm to estimate both capsule position and orientation. Inputs for the algorithm were the magnetic flux densities measured by the three pairs of tri-axial Hall-effect sensors. Experimental results showed an average error of 4.9 ± 2.7 mm and 3.3 ± 1.7° for position and orientation, respectively. However, the main disadvantage of this approach was the fact that propulsion and localization could not be carried out at the same time. In 2017, an improvement of their previous studies was presented in [46], proposing a real-time propulsion and localization strategy in order to localize the capsule without stopping the propulsive locomotion procedure with an average speed of 2.2 mm/s. The improvement was provided through the introduction of an extended Kalman filter and by the assumption that the capsule movement is restricted to translation and rotation along its principle longitudinal axis. Average position and orientation errors were 8.5 mm and 7.1°, respectively.