In this work, we analyze the effects of an inter-stage capacitor located between the power stage input and the driver stage output on the overall efficiency of a RF CMOS power amplifier and on gate-drain reliability problems. To verify the analyzed effects, we designed a RF CMOS power amplifier with a center frequency of 1.85GHz. Class-D amplifiers with a feedback resistor are used as driver st...

The class-E amplifier [1]-[11] is remarked as the next candidate of digital wireless power transmitters. Non-switching power amplifiers suffer from low power-conversion efficiency due to their inherent power loss in high back off area. Hence, switching power amplifiers such as class-D and E are remarked as a remedy for improving power-conversion efficiency and prolonging battery lifetime of por...

This paper presents the design of a capacitive power transfer (CPT) system by using the Class-E amplifier approach. The Class-E amplifier approach is chosen to be adopted since it produces high efficiency as close as to 100%, theoretically. Based on the Class-E approach, a design of wireless power transfer system is used to transfer power to a LED lamp. The system has an output around 4.2 watts...

We demonstrate power scaling of an Nd:YAG picosecond master oscillator power amplifier system to over 200 W. The ‘z-slab’ amplifier design is a power scalable, edge-pumped zigzag slab amplifier architecture, and it is demonstrated here in two alternative multi-stage implementations at 1064 nm using a picosecond seed laser. In a simple design, an average power of 225 W was generated with up to 4...

1. Abstract This paper presents the features of Instrumentation Amplifier for biomedical applications. This Instrumentation Amplifier is a device created from Operational Tran conductance Amplifier. It is designed to have input high impedance , output low impedance, low DC offset, low noise , high common mode rejection ratio and high power supply rejection ratio. The circuit has been integrated...

This paper presents the technique to dynamically enhance the power efficiency of PWM class-D amplifier over a wide range of modulation indexes. The power stage of amplifier is segmented into several small stages and selectively enabled according to the power demand (i.e. modulation indexes). The capability of power delivery is dynamically adjusted to minimize the power loss in case of different...

Radio signals typically are subject to very large transmission losses and distortions due to nonlinearities that might be added by the limited dynamic range of power amplifiers [1], [2]. Particularly, the signal gets distorted when the power amplifier is used at its full rated RF power level and/or Maximum efficiency is attained only at one single power level, usually closer to the maximum rate...

A high-linearity and high-efficiency MMIC power amplifier is demonstrated adopting a new on-chip adaptive bias circuit, which improves efficiency at the low output power level and linearity at the high output power level automatically. The intelligent two-stage W-CDMA power amplifier using the newly proposed adaptive bias circuit extends the maximum linear output power of 0.6dB and exhibits an ...

In this paper a comparison between a memoryless nonlinear power amplifier model and a special nonlinear model with memory (Wiener-model) based on measurements on a power amplifier is presented. With moderate signal bandwidths of only 2MHz the nonlinear model with memory outperforms the memoryless model. The amplifier model is intended to be used for pre-distortion purposes. Furthermore, an adap...

According to the shortage of the traditional offset line in Doherty power amplifier, a new offset line technique is proposed to match carrier amplifier with the load and to improve the performance of the Doherty amplifier. By simulation of the computer software, a higher efficiency is obtained using the new offset line comparing the two kinds of offset lines. The new offset line technique could...