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Parametric array transducers are used for long-range and highly directional communication in underwater environment. The power amplifiers for parametric array transducers should have sufficient linear output characteristic and high efficiency to avoid communication errors, system heating, and fuel problems. But the conventional power amplifier with fixed source voltage is very low efficient due to...
Parametric array transducers are used for highly directional speaker in an air environments. Piezoelectric micromachined ultrasonic transducers for parametric array transducers need DC-biased voltage driving signals in order to get high-directional quality-sound features. The existing power amplifier such as class A amplifiers has low efficiency and require large volume heatsinks. To overcome the...
Parametric array transducers are used for long-range and highly directional communication in an air or underwater environments. The power amplifiers for parametric array transducers should have sufficient linear output characteristic and high efficiency to avoid communication errors, system heating, and fuel problems. But the conventional power amplifier with fixed source voltage is very low efficient...
This paper presents a fully integrated triple-band CMOS hybrid-EER transmitter for WCDMA/LTE applications. The operation frequency bands are 0.8/2.3 GHz for LTE and 1.9 GHz for WCDMA applications with multi-band class-E power amplifier (PA) using a power cell resizing technique and a multitap transformer. The multi-mode envelope amplifier support 3.84-MHz WCDMA and 5-MHz LTE signal with a dual-switching...
This paper presents a new type of the hybrid envelope amplifier (HEA) using a switching-controlled structure for reconfigurable transmitters. The dual switching stage, controlled by an appropriate voltage with respects to the selected mode, is employed to obtain high efficiency. For verification, the proposed HEA has been fabricated using 0.35-µm CMOS technology within an area of 2.3 × 1.1 mm2 including...
This paper proposes a power combining amplifier based on composite right/left-handed (CRLH) transmission line. The circuits using proposed technique consist of the CRLH transmission line, that are series capacitors, shunt inductors and a right-handed (RH) transmission line, to replace the parallel capacitors and transmission line to satisfy matching conditions and to combine power. As a result, the...
In this paper, a third- and fifth-order analog predistorter using series feedback constituted individual predistorter of common-emitter amplifiers and schottky diodes has been developed. The individual order predistorters of the proposed circuit have shown the gain and phase control characteristics in order to compensate nonlinearity of amplifier with wide dynamic range. The individual predistorters...
This paper proposes a series feedback predistorter using junction resistance of schottky diode to compensate for AM/AM and AM/PM in the nonlinear characteristics of amplifier. This consists of common- emitter amplifier and schottky diode that is connected between emitter and ground. The common-emitter amplifier with varying resistance of schottky diode operates to increase amplitude and lead phase...
This paper proposes a predistortion linearizer using the in-phase modulator. The harmonic generator of the proposed predistorter extracts a second harmonic signal. These signals are divided in-phase and quadrature- phase signals, and then amplifying each signals using variable gain amplifier. An in-phase modulator, modulate fundamental signal with second harmonic signals, generates the predistortion...
This paper proposes a polar function linearizer to reduce the spectral regrowth of radio frequency power amplifier using even order harmonic signals. An AM modulator, modulate fundamental signal with even order harmonic signals, makes inverse transfer function of power amplifier and controls amplitude and phase of them with polar function factors. As a result, this polar function linearizer is suppressed...
In this paper, a new predistortion linearizer with controlling individual order intermodulation distortion (IMD) signals is proposed. This linearizer is achieved independent control of third- and fifth-order intermodulation products using amplitude modulation with even harmonic signals. A vector modulator, modulate fundamental signal with even harmonic components generated by harmonic generator circuits,...
In this paper, an analog linearizer using second harmonic signals feedforwarding is proposed. The harmonic generator of the proposed linearizer that consists of a small signal amplifier extracts second harmonic signals. A vector modulator, modulate fundamental signal with second harmonic signals, makes the inverse third order intermodulation distortion (IMD3) signals of power amplifier and controls...
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