Anyone who have designed a capacitively tuned VFO/VCO with the wide tuning range (>1.5-2x) has noticed that the oscillation threshold changes substantially with the tuning frequency. The usual solution to the problem is a combination of: 1. the AGC circuit, most frequently via the amplifier bias that changes the amplifier conduction angle; 2. shunting the LC circuit with a damping resistor or b...

The balanced amplifier is used in applications requiring a better input match than is possible with a single-ended amplifier. While the impedance matching property of the balanced amplifier is well known, its noise behavior appears not to be widely understood. It is shown that the outgoing noise waves at the input and output of a balanced amplifier are uncorrelated even though they originate in...

— A low power wideband noise amplifier (LNA) for 1GHz to 10GHz wireless has presented for wireless application in this dissertation work. Low power wideband noise amplifier is design by using resistive shunt feedback, current reuse, gain flatting techniques, and inductive feedback technique. The high mobility electron transistors are used to improve the Noise Figure (NF) and scattering paramete...

High sampling rate analog-to-digital converters (ADCs) are commonly used to sample complex modulated signals at intermediate frequencies in modern wireless receiver designs. Often CMOS switched-capacitor based ADCs are selected for such designs due to their attractive low cost and power dissipation. These ADCs utilize an unbuffered front end directly coupled to the sampling network, which prese...

As they are spread across almost all applications based on electrical circuits, frequency filters form one of the most complex issues on electronic devices. There exist a great number of different design methods based on various approaches. A large group of these filters is based on active components, namely amplifiers, that are equipped with the appropriate feedback to achieve the desired tran...

In the design of cascode CMOS low-noise amplifiers, the gate-drain capacitance is generally neglected because it is thought to be small enough compared to gate-source capacitance. However, a careful examination will reveal the fact that the drain impedance of the input transistor significantly affects the input impedance through the gate-drain capacitance, especially as the CMOS technology gett...

H. Nam, S. M. Wright Electrical Engineering, Texas A&M University, College Station, TX, United States INTRODUCTION: An RF power amplifier feeds power into a RF coil through matching networks and generates a transverse magnetic B1 field. In the conventional voltage source configuration, the matching networks ensure maximum power transfer between the RF amplifier and the coil. Assuming the coil i...

In this paper, the operational behavior of three-way Doherty amplifier loaded with harmonic control circuits is analyzed, including the efficiency and linearity. Amplifier is designed in configuration with two quarter-wave impedance transformers in the output combining circuit with LDMOSFETs in carrier and peaking amplifiers with the same periphery and in periphery relations 1:2.5:2.5. The sign...

a new output structure for class e power amplifier (pa) is proposed in this paper. a series lc resonator circuit, tuned near the second harmonic of the operating frequency is added to the output circuit. this resonator causes low impedance at the second harmonic. the output circuit is designed to shape the switch voltage of the class e amplifier and lower the voltage stress of the transistor. t...

We describe a custom-designed bio-amplifier and its use in teaching neurophysiology to undergraduate students. The amplifier has the following features: 1) differential amplification with driven shield inputs, which makes it workable even in electrically unshielded environments, 2) high input impedance to allow recordings of small signals through high signal source impedance, 3) dual fixed freq...