80 research outputs found
Modeling and characterization of on-chip interconnects, inductors and transformers
Ph.DNUS-SUPELEC JOINT PH.D. PROGRAMM
A dual-mode Q-enhanced RF front-end filter for 5 GHz WLAN and UWB with NB interference rejection
The 5 GHz Wireless LAN (802.11a) is a popular standard for wireless indoor communications providing moderate range and speed. Combined with the emerging ultra Wideband standard (UWB) for short range and high speed communications, the two standards promise to fulfil all areas of wireless application needs. However, due to the overlapping of the two spectrums, the stronger 802.11a signals tend to interfere causing degradation to the UWB receiver. This presents one of the main technical challenges preventing the wide acceptance of UWB.
The research work presented in this thesis is to propose a low cost RF receiver front-end filter topology that would resolve the narrowband (NB) interference to UWB receiver while being operable in both 802.11a mode and UWB mode. The goal of the dual mode filter design is to reduce cost and complexity by developing a fully integrated front-end filter. The filter design utilizes high Q passive devices and Q-enhancement technique to provide front-end channel-selection in NB mode and NB interference rejection in UWB mode.
In the 802.11a NB mode, the filter has a tunable gain of 4 dB to 25 dB, NF of 8 dB and an IIP3 between -47 dBm and -18 dBm. The input impedance is matched at -16 dB. The frequency of operation can be tuned from 5.15 GHz to 5.35 GHz. In the UWB mode, the filter has a gain of 0 dB to 8 dB across 3.1 GHz to 9 GHz. The filter can reject the NB interference between 5.15 GHz to 5.35 GHz at up to 60 dB. The Q of the filter is tunable up to a 250 while consuming a maximum of 23.4 mW of power. The fully integrated dual mode filter occupies a die area of 1.1 mm2
Planar microwave filters with electronically tunability and other novel configurations
In order to meet the increasing demands of advance wireless communications and
radar systems, several novel types of bandpass filters and bandstop filters have been
developed in this thesis.
A new type of varactor-tuned dual-mode bandpass filters have been presented to
achieve a nearly constant absolute bandwidth over a wide tuning range by using a single
DC bias circuit. Since the two operating modes (i.e., the odd and even modes) in a dualmode
microstrip open-loop resonator do not couple to each other, tuning the passband
frequency is accomplished by merely changing the two modal frequencies
proportionally. Design equations and procedures are derived, and two two-pole tunable
bandpass filters and a four-pole tunable bandpass filter of this type are demonstrated
experimentally.
Miniature microstrip doublet dual-mode filters that exhibit quasi-elliptic function
response without using any cross coupling have been developed. It shows that a single
two-pole filter or the doublet can produce two transmission zeros resulting from a
double behaviour of the dual-mode resonator of this type. Electromagnetic (EM)
simulation and experiment results of the proposed filters are described.
Parallel feed configuration of a microstrip quasi-elliptic function bandpass filter
has been built with a pair of open-loop dual-mode resonators. By employing this new
coupling scheme, a novel filter topology with three-pole quasi-elliptic function
frequency response can be obtained, leading to good passband performance, such as low
insertion loss and good matching at the mid-band of passband. A designed three-pole
bandpass filter of this type is demonstrated experimentally.
A new class of dual-band filters based on non-degenerate dual-mode microstrip
slow-wave open-loop resonators, which support two non-degenerate modes that do not
couple, have been introduced. Different feed schemes that affect the filtering
characteristics are investigated. Examples of dual-band filters of this type are described
with simulation and experiment results.
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In order to achieve a wide spurious-free upper passband, a novel design of
bandstop filter with cancellation of first spurious mode by using coupled three-section
step impedance resonators (SIRs) has been developed. This cancellation occurs when
two transmission poles coincide with the first spurious mode (transmission zero) by
properly choosing the step impedance ratio and the gap between the SIR and the main
transmission line. A stripline bandstop filter and a microstrip bandstop filter of this type
are designed, fabricated and tested. As a preliminary investigation, the microstrip filter
is tuned electronically using ferroelectric thin film varactors
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CMOS low noise amplifier design utilizing monolithic transformers
Full integration of CMOS low noise amplifiers (LNA) presents a challenge for low
cost CMOS receiver systems. A critical problem faced in the design of an RF CMOS LNA
is the inaccurate high-frequency noise model of the MOSFET implemented in circuit
simulators such as SPICE. Silicon-based monolithic inductors are another bottleneck in RF
CMOS design due to their poor quality factor.
In this thesis, a CMOS implementation of a fully-integrated differential LNA is
presented. A small-signal noise circuit model that includes the two most important noise
sources of the MOSFET at radio frequencies, channel thermal noise and induced gate
current noise, is developed for CMOS LNA analysis and simulation. Various CMOS LNA
architectures are investigated. The optimization techniques and design guidelines and
procedures for an LC tuned CMOS LNA are also described.
Analysis and modeling of silicon-based monolithic inductors and transformers are
presented and it is shown that in fully-differential applications, a monolithic transformer
occupies less die area and achieves a higher quality factor compared to two independent
inductors with the same total effective inductance. It is also shown that monolithic
transformers improve the common-mode rejection of the differential circuits
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Emergent Functionality and Controllability in Beamforming System
This dissertation presents beamforming designs. Using novel techniques and methods, the performance of the beamforming is improved on dual-band, tri-band, flexible function, tunable function in THz, and dynamic controllability on incident wave
ANALYSIS AND DESIGN OF SILICON-BASED MILLIMETER-WAVE AMPLIFIERS
Ph.DDOCTOR OF PHILOSOPH
An Integrated Single-phase On-board Charger
With the growing demand for transportation electrification, plug-in electric vehicles (PEVs), and plug-in hybrid electric vehicles (PHEVs), cumulatively called electric vehicles (EVs) are drawing more and more attention. The on-board charger (OBC), which is the power electronics interface between the power grid and the high voltage traction battery, is an important part for charging EVs. Besides the OBC, every EV is equipped with another separate power unit called the auxiliary power module (APM) to charge the low voltage (LV) auxiliary battery, which supplies all the electronics on car including audio, air conditioner, lights and controllers. The main target of this work is a novel way to integrate both units together to achieve a charger design that is not only capable of bi-directional operation with high efficiency, but also higher gravimetric and volumetric power density, as compared with those of the existing OBCs and APMs combined.
To achieve this target, following contributions are made: (i) a three-port integrated DC/DC converter, which combines OBC and APM together through an innovative integration method; (ii) an innovative zero-crossing current spike compensation for interleaved totem pole power factor correction (PFC) and (iii) a new phase-shift based control strategy to achieve a regulated power flow management with minimum circulating losses
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