A programmable-gain amplifier and an active inductor for in-vehicle power line communications

• Main Author: Zhang, Xiaolang
• Language: English
• Published: University of British Columbia 2011
• Online Access: http://hdl.handle.net/2429/37014

In-vehicle power-line communication (VPLC) is a communication technique that uses the power lines of the vehicle for data transmission. Based on the measurements of the power line communication channel, the channel response is characterized as frequency selective, time and location dependent with high signal attenuation. Also, the access impedance changes a lot in different frequency ranges. These properties impose design challenges at both system level and circuit levels of a VPLC system. This thesis presents the design of two critical building blocks of a VPLC system, namely, a variable gain amplifier (VGA) and an active inductor. VGAs are used to amplify the signal to a predefined level without introducing too much distortion. The presented VGA design targets a 0.13μm CMOS technology. The VGA design is discussed in detail. Gm-boosting technique is used to both increases the linearity and provide a programmable 0 dB to 60 dB gain over a broadband. Furthermore, the gain is stable over a wide range of temperatures. The circuit is fabricated and tested, and the measured results are in good agreement with the simulation results. Inductors are commonly used in impedance matching networks. In this work, an active inductor circuit is designed which provides a wide tuning range for VPLC LC matching networks. Active inductor is a good candidate to replace the passive inductor in the LC matching network since it has a smaller area, wider tuning range, and a higher quality-factor. The designed active inductor is a fully differential grounded Gyrator-C active inductor. Simulation results confirm that the inductor has wide tuning range with linear tuning ability; however, its bandwidth is limited. The circuit design for this VPLC system is challenging, the preliminary results of the proposed circuits show some promise; however, further work is still needed to improve the performance.