The ever-increasing demand for global mobility and multi-media services has
motivated the realizations of multi-mode, multi-band and multi-standard wireless
communication systems. Software-defined radio (SDR), in which some or all of the
physical layer functions are software defined, encompasses a wide range of design
techniques to realize fully reconfigurable transceiver systems. It is an attractive radio
platform that covers not only all the existing wireless standards (including cellular,
WLAN, WPAN, broadcast, positioning, etc,) but also the future standards. Such a
radio requires ultra-wideband (UWB) in-phase and quadrature-phase (IQ) local
oscillation (LO) signals with sufficiently high spectrum purity to support diverse
specifications. In this thesis, several novel circu...[
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The ever-increasing demand for global mobility and multi-media services has
motivated the realizations of multi-mode, multi-band and multi-standard wireless
communication systems. Software-defined radio (SDR), in which some or all of the
physical layer functions are software defined, encompasses a wide range of design
techniques to realize fully reconfigurable transceiver systems. It is an attractive radio
platform that covers not only all the existing wireless standards (including cellular,
WLAN, WPAN, broadcast, positioning, etc,) but also the future standards. Such a
radio requires ultra-wideband (UWB) in-phase and quadrature-phase (IQ) local
oscillation (LO) signals with sufficiently high spectrum purity to support diverse
specifications. In this thesis, several novel circuit topologies and design techniques
are proposed and integrated to realize for the very first time an ultra-wideband
frequency generation system (FGS) for SDRs in low-cost CMOS processes.
Firstly, complete analysis is derived and presented for both dual-band one-port
and two-port oscillators using transformer-based fourth-order LC tanks. Based on the
results, a dual-band quadrature voltage-controlled oscillator (Q-VCO) is
systematically designed and implemented in a 0.13-μm CMOS process for SDR
applications. The prototype achieves a dual-band operation with IQ output signals from 2.7GHz to 4.3GHz and from 8.4GHz to 12.4GHz.
Secondly, novel current-bleeding (CB) and current-reusing (CR) techniques are
proposed, to efficiently enlarge and maximize the locking ranges of injection-locked
frequency dividers (ILFDs) and Miller dividers (MD) without extra inductive
components and extra power consumption. Implemented in a 0.13μm CMOS, two
CR-ILFD prototypes, operating with 7GHz and 60GHz inputs, achieve around 3x and
2x locking range improvement, respectively. In addition, a 60GHz CB-MD prototype
improves the locking range by more than 5x.
Thirdly, new circuit topologies, including a reconfigurable injection locking
based frequency multiplier and a tunable 3GHz-to-10GHz transformer-based
narrow-band LC-tank for single sideband (SSB) mixers, are proposed to implement
the 14-band MB-OFDM UWB carrier generator into the FGS. Experimentally, the
generator achieves sideband rejections (SBRs) better than 31dB for all the 14-band
carriers from 3GHz to 10GHz.
Fourthly, a novel interpolative-phase-tuning technique is proposed to implement
varactor-less multi-phase LC oscillators with a wide tuning range and a low phase
noise at millimeter-wave (MMW) frequencies. Two phase-tuning oscillator
prototypes, one with 8-phase 50GHz outputs and another with 4-phase 60GHz outputs,
achieve state-of-the-art performance in terms of phase noise, figure-of-merit (FOM),
and figure-of-merit with tuning range (FOM
T).
Fifthly, an alternative method of using high frequency multipliers to synthesize
the MMW LO frequencies is also investigated. Two injection-locked frequency
multiplier (ILFM) chains are designed and demonstrated to provide LO signals for
both direct-conversion and dual-conversion transceivers operating at 60GHz band. A
proposed automatic peak calibration technique is also implemented for the ILFM chain to effectively improve the output swing and the spur rejection performance
with a small area and low power.
Finally, employing these circuit techniques and topologies, a wideband SDR
frequency generation system with a reconfigurable phase-locked loop, is proposed
and demonstrated. The prototype successfully provides IQ LO signals with
sufficiently good phase noise not only from 47MHz to 10GHz but also from 18GHz
to 22.5GHz and from 37GHz to 44GHz for all the wireless standards (including
GSM900/DCS/PCS, UMTS, WLAN, WiMAX, Bluetooth, DECT, ZigBee, DVB-T/H,
GPS, UHF-RFID, MB-OFDM UWB and UWB 802.15.3c).
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