– In this paper the operation behavior of three-way Doherty amplifier is analyzed, including the efficiency and linearity. Amplifier is designed in the configuration with two quarter-wave impedance transformers in the output combining circuit with LDMOSFETs in carrier and peaking amplifies. The signals for linearization (the fundamental signals’ second harmonics-IM2 and fourth-order nonlinear s...

eGaN FETs have repeatedly demonstrated higher efficiency than MOSFETs in wireless power transfer amplifiers when operated over a wide impedance range using a ZVS Class D amplifier [1, 2, 3, 4, 5, 6, 7, and 8]. In this article we examine a method to further improve the performance of eGaN FETs by replacing the bootstrap diode of the high side gate driver with an eGaN FET that is driven synchrono...

A bioimpedance detector is developed as part of instrumentation for impedance cardiography. It uses slicing amplifier for increasing the sensitivity for the impedance variation and synchronous sampling for a ripple-free output. The circuit provides digital control of excitation current and frequency used for the measurement. Its operation has been verified using a thorax simulator for detecting...

A tunable high-Q resonator is performed in the schematics of General Impedance Converter (GIC). In framework frequency dependent open-loop gain operational amplifiers, a general formula dependence impedance GIC derived. The explicit formulas for resonance and Q-factor include as an immanent parameter crossover amplifier. Voltage measurements with lock-in amplifier perfectly agree derived formul...

The design procedure of low-sensitivity active resistance-capacitance (RC) allpole filters, using impedance tapering, has already been published. The low-sensitivity filter sections already described in publication are class 4 (TT-SABB) Sallen and Key sections. In this paper class 3 (SAB) sections for low pole-Q realization are considered. Impedance tapering is applied on Lsections, which are ...

Negative impedance converter circuits (NICs) are important building blocks in design and manufacturing of analog and mixed mode integrated circuits. In this paper, a catalogue of single current feedback amplifier-based negative impedance converter circuits having impedance scaling properties is proposed. Various examples are presented to illustrate the versatility of proposed NIC circuits.

An electronic amplifier, amplifier, or (informally) amp is an electronic device that increases the power of a signal. It does this by taking energy from a power supply and controlling the output to match the input signal shape but with a larger amplitude. Amplifier design relies on feedback mechanism. Offsets that accumulate in different stages of amplifier are corrected by feedback mechanism. ...

Introduction: Noise reduction is an important issue for SNR (Signal to Noise Ratio) maximization in MR measurements, therefore a low-noise amplifier should be used as first element in the spectrometer’s receive chain. Since the Noise Figure (NF) of an amplifier changes depending on the impedance seen by the amplifier at its input port, a matching network is commonly placed between this low-nois...

In this paper we look at the load presented to audio amplifiers by real transducers. We consider the power losses in Class-AB and Class-D amplifier topologies, and determine that in order to predict efficiency it is necessary to consider the amplifier/transducer combination. The ability of the class-D amplifier to recycle quadrature load current offers new ways to improve efficiency. INTRODUCTI...

In this paper we look at the load presented to audio amplifiers by real transducers. We consider the power losses in Class-AB and Class-D amplifier topologies, and determine that in order to predict efficiency it is necessary to consider the amplifier/transducer combination. The ability of the class-D amplifier to recycle quadrature load current offers new ways to improve efficiency. INTRODUCTI...