In RFID reader systems, power amplifier plays a critical rule for efficiency enhancement. A high efficiency power amplifier may not only increase the life expectancy of portable RFID devices but also reduce the reliance on heat sinks. Heat sinks usually occupy plenty of space and lead to packing difficulties. A well-designed power amplifier with high efficiency and output power may also increas...

Abstract- A novel low-voltage two-stage operational amplifier employing resistive biasing is presented. This amplifier implements neutralization and correction common mode stability in second stage while employs capacitive dc level shifter and coupling between two stages. The structure reduces the power consumption and increases output voltage swing. The compensation is performed by simple mill...

As the mobile phone is an essential accessory for everyone nowadays, predistortion for the RF power amplifiers in mobile phone systems becomes more and more popular. Especially, new predistortions for power amplifiers with both nonlinearities and memory effects interest the researchers. In our thesis, novel predistortion techniques are presented for this purpose. Firstly, we improve the digital...

Fig.2 Amplifier under test. Amplifiers can operate in classes A, B, AB, C, D, E and F [2]. We tested class A amplifier made by „Microwave Power Devices“, Model: LWA 4690-1/1837, based on bipolar devices (Fig.2). Usually, 1dB compression point, gain and two-tone third-order intercept point are measured as the amplifier figure of merit. As specified by manufacturer, the frequency range of the amp...

In this paper, an lateral diffused metal–oxide– semiconductor-based very high-frequency class-E power amplifier has been investigated theoretically and experimentally. Simulations were verified by amplifier measurements and a record-high class-E output power was obtained at 144 MHz, whic is in excellent agreement with simulations. The key of the results is the use of efficient device models, si...