Bo Yang 교수

A new LLC resonant converter is proposed for front end DC/DC conversion in a distributed power system. Three advantages are achieved with this resonant converter. First, ZVS turn on and low turn off current of MOSFETs are achieved. The switching loss is reduced so we can operate the converter at higher switching frequency. The second advantage is that with this topology, we can optimize the converter at high input voltage. Finally, with this topology, we can eliminate the secondary filter induct

A new LLC resonant converter is proposed for front end DC/DC conversion in a distributed power system. This converter shows some potential benefits in this application. This paper proposes several integrated magnetic designs for LLC resonant converter. This converter has three magnetic components. With magnetic integration, first, a number of components can be reduced; secondly, flux ripple cancellation is achieved so that core loss is reduced. From these benefits, higher power density can be ac

LLC resonant converter was getting more and more attention in recent years because of its high efficiency, high frequency operation capability and simple structure. In this paper, the over current protection issue of LLC resonant converter is discussed. Three methods to provide over current protection function for LLC converter are proposed and investigated. They are: increase switching frequency control, variable frequency+PWM control, and diode clamping method. The pros and cons for each metho

With the fast advance in VLSI technology, smaller, more powerful digital system is available. It requires power supply with higher power density, lower profile and higher efficiency. PWM topologies have been widely used for this application. Unfortunately, hold up time requirement put huge penalties on the performance of these topologies. Also, high switching loss limited the power density achievable for these topologies. Two techniques to deal with hold up time issue are discussed in this disse

Hold up time requirement is a special requirement for a front end (FE) converter. The converter needs to provide output voltage within regulation for 20 ms after the AC input is lost. When designing the FE DC/DC converter, we want it to operate over a wide input range so that we can use less high voltage bus capacitor to meet the requirement. The converter efficiency is reduced at normal operating conditions, in order to cover wide input range. This paper demonstrates a new method to cover wide

We build a phased array system with four power-variable phase-controlled magnetrons (PCMs) by applying the injection-locking method and phase-locked-loop method. To reduce the cost and ensure the durability of the phased array, a waveguide slot array antenna was designed and used for the output antenna of power-variable PCMs. The slot antenna has an expected angle deflection of 22.5°, a gain of 24.9 dBi, and the half bandwidth of the main lobe was 10°. We demonstrated the properties of microwave

This paper proves that 2.45- and 5.8-GHz band continuous-wave magnetrons can be used to perform amplitude, phase, and frequency modulations by applying an injection-locking method. The magnetron behaved like an amplifier, and its output could follow the injection signal. In addition, we have achieved the transmission of amplitude-shift keying data at 200 kb/s as well as phase-shift keying and frequency-shift keying at 10 Mb/s. Moreover, we quantitatively discussed several demodulation performanc

This article used image recognition and beam forming technology to build a phased array with target tracking and transmitting the microwaves with a focused beam. The coordinate position of the target is obtained from the image recognition module and converted into phase information for the phased array. This system was constructed by a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1\times4\,\,5.764$ </tex-ma

With communication systems designed for operation in the millimeter wave frequencies it is now possible to have most of the transceiver implemented on a single CMOS die. An important system component that is required to ensure regulatory compliance is the RF bandpass filter. Unfortunately to date RF bandpass filters have been difficult to integrate on CMOS because of filter size and undesirable performance due to the conductive substrate. In this paper a six step method for the design of integra

We built a phased array system for high-power simultaneous wireless information and power transfer (SWIPT) using four 5.8-GHz injection-locked magnetrons. In the magnetron injection-locked state, the transmission efficiency was measured at different modulation rates. The fluctuation in the transmission efficiency was not more than 0.5%. We observed that dynamic beamforming does not affect communication quality. Using the magnetron phased array system, SWIPT experiments revealed that a frequency

A 60 GHz integrated second-order bandpass filter using rectangular open-loop resonators was designed and fabricated on a 0.13 µm standard CMOS process. The size of the filter is 415.5×502.8 µm2. The designed filter has a pair of transmission zeros at finite frequencies in the stopband, exhibiting good selectivity. The measured filter with the grid ground plane has a flat passband and its 1 dB bandwidth is 9 GHz (59.5–68.5 GHz). The insertion loss is about 2.6 dB and the return loss is better tha

We developed a 5.8 GHz power-variable phase-controlled magnetron (PVPCM) which controls the phase of magnetron output by a phase shifter and controls the power by the anode current of the magnetron. This method is different from the previous 2.45 GHz phase-controlled magnetron which utilizes an injection method and a phase locked loop by the anode current, since the frequency of 5.8 GHz magnetron hardly changes with the anode current. Our experiments show that the developed 5.8 GHz PVPCM had a v

In this study, a novel on-chip low-loss slow-wave slot (SWS) microstrip transmission line is proposed. Unlike conventional slow-wave structures such as photonic bandgap and ladder microstrip transmission line, which usually deal with either the substrate, ground plane or the signal line separately, the periodic patterns of SWS structures are etched along both the conductive metal strip and the ground plane of the microstrip line. The proposed structure, unlike other slow-wave structures does not

A new 60 GHz fourth-order cross-coupled bandpass filter using a step-impedance-resonator (SIR) miniaturised open-loop resonator and the miniaturised-hairpin (MH) resonator was designed and fabricated on 0.13 µm bulk CMOS. It has 8.5 GHz (58–66.5 GHz) bandwidth, 5.9 dB insertion loss, and better than 10 dB return loss over the whole passband, and exhibits high selectivity and a compact size of 714.9×484 µm (0.346 mm2). This filter is the first reported cross-coupled filter above 40 GHz on CMOS.

Modern systems require transceivers that deliver gigabit speeds, are smaller in size, and have lower power consumption and cost. This motivates research to develop transceiver-on-chip and transceiver-in-a-package technologies. Recent advances in millimetre wave electronics have meant that significant portions of the system can now be integrated onto a single substrate or package. In order to achieve low costs and high digital integration CMOS is the process of choice as CMOS is the standard and