Flexible Receivers in CMOS for Wireless Communication
Författare
Summary, in English
Consumers are pushing for higher data rates to support more services that are introduced in mobile applications. As an example, a few years ago video-on-demand was only accessed through landlines, but today wireless devices are frequently used to stream video. To support this, more flexible network solutions have merged in 4G, introducing new technical problems to the mobile terminal. New techniques are thus needed, and this dissertation explores five different ideas for receiver front-ends, that are cost-efficient and flexible both
in performance and operating frequency. All ideas have been implemented in chips fabricated in 65 nm CMOS technology and verified by measurements.
Paper I explores a voltage-mode receiver front-end where sub-threshold positive feedback transistors are introduced to increase the linearity in combination with a bootstrapped passive mixer. Paper II builds on the idea of 8-phase harmonic rejection, but simplifies it to a 6-phase solution that can reject noise and interferers at the 3rd order harmonic of the local oscillator frequency. This provides a good trade-off between the traditional quadrature mixer and the 8-
phase harmonic rejection mixer. Furthermore, a very compact inductor-less low noise amplifier is introduced. Paper III investigates the use of global negative feedback in a receiver front-end, and also introduces an auxiliary path that can cancel noise from the main path. In paper IV, another global feedback based receiver front-end is designed, but with positive feedback instead of negative. By introducing global positive feedback, the resistance of the transistors in a passive mixer-first receiver front-end can be reduced to achieve a lower noise figure, while still maintaining input matching. Finally, paper V introduces a full receiver chain with a single-ended to differential LNA, current-mode downconversion
mixers, and a baseband circuity that merges the functionalities of
the transimpedance amplifier, channel-select filter, and analog-to-digital converter into one single power-efficient block.
in performance and operating frequency. All ideas have been implemented in chips fabricated in 65 nm CMOS technology and verified by measurements.
Paper I explores a voltage-mode receiver front-end where sub-threshold positive feedback transistors are introduced to increase the linearity in combination with a bootstrapped passive mixer. Paper II builds on the idea of 8-phase harmonic rejection, but simplifies it to a 6-phase solution that can reject noise and interferers at the 3rd order harmonic of the local oscillator frequency. This provides a good trade-off between the traditional quadrature mixer and the 8-
phase harmonic rejection mixer. Furthermore, a very compact inductor-less low noise amplifier is introduced. Paper III investigates the use of global negative feedback in a receiver front-end, and also introduces an auxiliary path that can cancel noise from the main path. In paper IV, another global feedback based receiver front-end is designed, but with positive feedback instead of negative. By introducing global positive feedback, the resistance of the transistors in a passive mixer-first receiver front-end can be reduced to achieve a lower noise figure, while still maintaining input matching. Finally, paper V introduces a full receiver chain with a single-ended to differential LNA, current-mode downconversion
mixers, and a baseband circuity that merges the functionalities of
the transimpedance amplifier, channel-select filter, and analog-to-digital converter into one single power-efficient block.
Avdelning/ar
Publiceringsår
2015
Språk
Engelska
Fulltext
Dokumenttyp
Doktorsavhandling
Ämne
- Other Electrical Engineering, Electronic Engineering, Information Engineering
Status
Published
Projekt
- EIT_DARE Digitally-Assisted Radio Evolution
Forskningsgrupp
- Analog RF
Handledare
Försvarsdatum
24 november 2015
Försvarstid
10:15
Försvarsplats
Lecture hall E:1406, building E, Ole Römers väg 3, Lund University, Faculty of Engineering LTH, Lund
Opponent
- Eric Klumperink