Article

Polyphase multipath radio circuits for dynamic spectrum access

Twente Univ., Enschede
IEEE Communications Magazine (Impact Factor: 4.01). 06/2007; 45(5):104 - 112. DOI: 10.1109/MCOM.2007.358856
Source: IEEE Xplore

ABSTRACT

Dynamic access of unused spectrum via a cognitive radio asks for flexible radio circuits that can work at an arbitrary radio frequency. This article reviews techniques to realize radios without resorting to frequency selective dedicated filters. In particular, a recently proposed polyphase multipath technique canceling harmonics and sidebands is discussed. Using this technique, a wideband and flexible power upconverter with a clean output spectrum has been realized on a CMOS chip, aiming at flexible radio transmitter application. Prototype chips can transmit at an arbitrary frequency between DC and 2.4 GHz. Unwanted harmonics and sidebands are more than 40 dB lower than the desired signal up to the 17th harmonic of the transmit frequency

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    • "MAGINE the potential offered if electronic devices, such as computers, cell phones, digital cameras, MP3 players, flat panels, and external hard disks wirelessly connect to each other at speeds similar to the processing capabilities of modern computers. Although it is clear that advances in the semiconductor industry provide some of the tools for these ideas to become reality [millimeter-wave radio (mmWR) [1], [2], software-defined radio [3], [4], cognitive radio (CR) [5], [6], [54] and multistandard radio [4], [7]], there remain challenging issues that prevent wireless multichannel systems from coming to fruition. For instance, in applications such as power-spectral-density estimation for CRs [6], [8] and future mmWR standards , several gigahertz of bandwidth with high dynamic-range Manuscript received February 05, 2010; revised May 19, 2010; accepted July 07, 2010. "
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    • "MAGINE the potential offered if electronic devices, such as computers, cell phones, digital cameras, MP3 players, flat panels, and external hard disks wirelessly connect to each other at speeds similar to the processing capabilities of modern computers. Although it is clear that advances in the semiconductor industry provide some of the tools for these ideas to become reality [millimeter-wave radio (mmWR) [1], [2], software-defined radio [3], [4], cognitive radio (CR) [5], [6], [54] and multistandard radio [4], [7]], there remain challenging issues that prevent wireless multichannel systems from coming to fruition. For instance, in applications such as power-spectral-density estimation for CRs [6], [8] and future mmWR standards , several gigahertz of bandwidth with high dynamic-range Manuscript received February 05, 2010; revised May 19, 2010; accepted July 07, 2010. "

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