A High-Gain Multiphase Interleaved Differential Capacitor Clamped Boost Converter

A step-up for a non-isolated interleaved differential capacitor clamped boost (IDCCB) DC–DC converter is proposed in this manuscript. Because of its ability to produce high voltage gains, it is used in high-power applications. This converter’s modelling and control design are applicable to any number of phases. A six-phase interleaved differential capacitor clamped boost prototype is tested in this work, with an input voltage of 60 V, an output voltage of 360 V, and a nominal output power of 2.2 kW. The components of the converter are placed and controlled in such a way that the output voltage is the sum of the two capacitor voltages and the input voltage, which is two times higher than the supply voltage when compared to a conventional interleaved differential dual-boost converter. This converter reduces the stress on the capacitor with reference to the conventional interleaved differential boost converter for the same conversion gain. This prototype is considered and the developed approach is applied, after which the experimental results are obtained. This converter has potential for application in areas such as renewable energy conversion and electric vehicles.

A Low-Noise, High-Gain, and Small-Size UWB Mixer Utilizing Negative Impedance Technique and Source Input Method

This paper presents an ultra-wideband (UWB) down-conversion mixer with low-noise, high-gain and small-size. The negative impedance technique and source input method are applied for the proposed mixer. The negative impedance achieves the dynamic current injection and increases the mixer output impedance, which reduces the mixer flicker noise and increases its conversion gain. The source input method allows the input matching networks to be cancelled, avoiding the noise and loss introduced by the matching resistors, saving the chip area occupied by the matching inductors. The proposed mixer is designed in 45-nm SOI process provided by GlobalFoundries. The simulation results show a conversion gain of 11.4–14.3 dB, ranging from 3.1 to 10.6 GHz, a minimum noise figure of 9.8 dB, a RF port return loss of less than −11 dB, a port-to-port isolation of better than −48 dB, and a core chip area of 0.16 × 0.16 mm2. The power consumption from a 1 V supply voltage is 2.85 mW.

Wireless power transfer with transmit diversity

Background: Wireless power transfer is important for energizing and recharging the Internet-of-Things (IoT) cordlessly. Harnessing energy effectively from radio waves has become a crucial task. It is known that diversities at the transmitting antenna and waves (i.e. simultaneous continuous waves with center frequencies separated apart) can enhance the radio frequency (RF) to direct current (DC) energy conversion. What remains unknown is the extent of which the wave diversity enhances the conversion gain. This study attempts to examine the RF-to-DC conversion gain of applying wave diversity. This paper investigates the effects of wave diversity on the energy conversion efficiency, and contributes the analytical expression that relate the conversion efficiency to the diversity count, i.e. the number of simultaneously transmitted sinewaves. Methods: We adopted a theoretical approach to the problem. First, we derived and presented a theoretical model that incorporated different forms of transmit diversity, i.e. antenna and wave diversities. This model then connected a RF-to-DC energy conversion model resulting from polynomial fitting on circuit simulation results. With the availability of these two models, we determined the theoretical energy conversion gain of simultaneously transmitting multiple sinewaves. Results: The results showed that transmitting multiple sinewaves simultaneously yields diversity gain and higher energy conversion efficiency. Most importantly, the gain and conversion efficiency can now be theoretically quantified. For example, at certain RF power measured at the receiver circuit, the diversity gain of transmitting four sinewaves is 2.6 (as compared to transmitting single sinewave). In fact, both the diversity gain and conversion efficiency increased with the number of simultaneously transmitted sinewaves. In another example, the conversion efficiency of transmitting four sinewaves is 0.1 as compared to 0.075 of two sinewaves. Conclusions: In summary, this paper presents a novel analytical expression for wave diversity in the context of wireless power transfer.