A single stage wideband amplifier based on an AlGaN/GaN HEMT power cell with a total gate-width of 16 mm matched to 50 Ohm has been successfully developed and characterized by use of a single-carrier W-CDMA signal. A very wide bandwidth of more than 1.7 GHz covering several mobile radio frequency bands within Land S-band with peak output power levels up to 44 dBm has been demonstrated with meet...

patients with valvular heart disease and suffering atrial fibrillation of more than 12 months duration have a low probability of remaining in sinus rhythm after valve surgery alone. we performed intra-operative radiofrequency ablation or cryoablation as an alternative to surgical maze ііі procedure to create linear lesion lines for conversion of this arrhythmia to sinus rhythm. a total of 30 pa...

the graphical technique for nonlinear circuits was described that enable us to optimize circuits to obtain maximum output power, maximum efficiency or minimum intermodulation. according to this method a high power amplifier in the ka band was designed. using a nonlinear model of the transistor, optimum slope for load-line was determined so that maximum power at the output was obtainable, then ...

external amplifier was able to detect the sound waves from microphone on speaker and oscilloscope. The maximum amplitude of output speech signal of amplifier is 45 mV, and the maximum output of MEMS microphone is 1.125 µV.

The power amplifiers are typically the most power-consuming block in wireless communication systems. Spectrum is expensive, and newer technologies demand transmission of maximum amount of data with minimum spectrum usage. This requires sophisticated modulation techniques, leading to wide, dynamic signals that require linear amplification. Although linear amplification is achievable, it always c...

In this paper, a complete design procedure, together with robust system validation approaches, is presented for implementing a high-performance re-configurable digital predistortion (DPD) test platform for compensating for nonlinear distortion and memory effects induced by radio frequency (RF) power amplifiers (PAs) in the transmitters of modern wireless communication systems. This hardware and...

Introduction Array coil preamplifiers are subjected to large magnetic fields since they are placed close to each coil to minimize SNR losses due to cabling. Noise figure (NF) and input impedance are key parameters that must vary minimally with magnetic field strength and orientation [1,2] to ensure there are no differences in performance between the bench and the bore. In this work we compare t...

An electrically floating radiofrequency (RF) pre-ionization plasma source has been developed to enable neutral gas breakdown at lower pressures and to access new experimental regimes in the Caltech laboratory astrophysics experiments. The source uses a customized 13.56 MHz class D RF power amplifier that is powered by AA batteries, allowing it to safely float at 3-6 kV with the electrodes of th...

A radiofrequency interferometic detector is combined with the correlation-and-averaging technique in a new scheme for the measurement of the phase noise of a component. The method relies upon the assumption that the phase noise of the component being tested (DUT) exceeds the amplitude noise, which is consistent with the general experience in the field of wireless engineering. The new scheme is ...

This article proposed a simple self cascode RGC amplifier configuration to increase the gain and bandwidth. The cascode amplifier eliminates the miller capacitance between input and output and facilitates high gain, high input and output impedance with high bandwidth. However, the cascode amplifier requires relatively high supply voltage for proper operation and it decreases the output voltage ...