Architecture of a low cost spread spectrum wireless transceiver

Author(s):  
H. LeBlanc ◽  
J. Belzile ◽  
G. Delisle ◽  
N. Batani
Author(s):  
J. Kuhne ◽  
A. Nahler ◽  
M. Hosemann ◽  
G.P. Fettweis ◽  
G. Kovacs ◽  
...  
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Author(s):  
Anis Nurashikin Nordin

Today’s high-tech consumer market demand complex, portable personal wireless consumer devices that are low-cost and have small sizes. Creative methods of combining mature integrated circuit (IC) fabrication techniques with innovative radio-frequency micro-electro-mechanical systems (RF-MEMS) devices has given birth to wireless transceiver components, which operate at higher frequencies but are manufactured at the low-cost of standard ICs. Oscillators, RF bandpass filters, and low noise amplifiers are the most critical and important modules of any wireless transceiver. Their individual characteristics determine the overall performance of a transceiver. This chapter illustrates RF-oscillators that utilize MEMS devices such as resonators, varactors, and inductors for frequency generation. Emphasis will be given on state of the art RF-MEMS components such as film bulk acoustic wave, surface acoustic wave, flexural mode resonators, lateral and vertical varactors, and solenoid and planar inductors. The advantages and disadvantages of each device structure are described, with reference to the most recent work published in the field.


Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1385 ◽  
Author(s):  
José Moreno ◽  
Fernando Álvarez ◽  
Teodoro Aguilera ◽  
José Paredes

Self-calibrated Acoustic Local Positioning Systems (ALPS) generally require a high consumption of hardware and software resources to obtain the user’s position at an acceptable update rate. To address this limitation, this work proposes a self-calibrated ALPS based on a software/hardware co-design approach. This working architecture allows for efficient communications, signal processing tasks, and the running of the positioning algorithm on low-cost devices. This fact also enables the real-time system operation. The proposed system is composed of a minimum of four RF-synchronized active acoustic beacons, which emit spread-spectrum modulated signals to position an unlimited number of receiver nodes. Each receiver node estimates the beacons’ position by means of an auto-calibration process and then computes its own position by means of a 3D multilateration algorithm. A set of experimental tests has been carried out where the feasibility of the proposed system is demonstrated. In these experiments, accuracies below 0.1 m are obtained in the determination of the receptor node position with respect to the set of previously-calibrated beacons.


2018 ◽  
Vol 51 (7-8) ◽  
pp. 213-222 ◽  
Author(s):  
Muhd Nazrul Hisham Zainal Alam ◽  
Jayanth Jaya Kumar ◽  
Daniel John Whyte ◽  
Egan H Doeven ◽  
Abbas Kouzani

This paper presents the development of a smartphone-controlled wireless device for cell optical density sensing in microfluidic chips. The footprint of the device is very compact relative to a classical laboratory spectrophotometer, making it a portable device. The cell optical density sensing device consists of an embedded microcontroller, optical sensing components, and a wireless transceiver performing cell optical density measurements in disposable microfluidic chips fabricated from poly(methylmethacrylate) polymers. The device is controlled by an Android application allowing for true portability and the possibility of remote or field operation of the device. The use of microfluidic chips as the sample carrier for optical density detection instead of a plastic cuvette allows users the flexibility to explore and/or conduct a variety of micro-scale chemical analysis using the device which would be difficult in a cuvette-based system. The function of the device is validated through a series of off-line and online optical density measurements using Saccharomyces cerevisae yeast cultures. The device is low cost, small enough to fit in most laboratory flow hood cabinets, and can be easily integrated into miniature bioreactor systems. Moreover, wireless communication enables the user to operate the device using smartphones or rapidly transfer the measured data to an online repository for analysis or storage.


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