In multicarrier systems, the transmitted timedomain signal exhibits large amplitude peaks. This peak-toaverage power ratio (PAPR) problem complicates the practical use of multicarrier systems: the amplifier used to transmit the signal saturates because of the large peaks and causes non-linear distortion. As this non-linear distortion frustrates severely the detection of the multicarrier signal,...

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 ...

Abstract In this paper a promising novel output voltage filtering concept for multi-cell switch-mode power amplifiers is analyzed. The proposed hybrid filtering concept is based on a passive LC filter enhanced by a linear-mode correction stage of small rated power. Using this principle, also "sub-harmonic" (i.e. low-frequency) switching noise distortions (typically appearing in real interleaved...

In this paper, an ultra-low-noise amplifier with frequency band switching capability is designed, simulated and fabricated. The two frequency ranges of this amplifier consist of the 2.4 to 2.5 GHz and 3.1 GHz to 3.15 GHz frequency bands. The designed amplifier has a noise figure of less than 1dB, a minimum gain of 23 dB and a VSWR of less than 2 in the whole frequency band. The design process s...

This work proposes a direct sequence spread spectrum transmitter with high transmission range and efficiency for audio signals. It is shown that by choosing high process gain for spread spectrum signal the data could reach a range of 55km in the 2.4GHz ISM band. By employing a light modulation scheme, we have a relaxed SNR requirement for having a low bit error rate (BER) which translates to re...

The design of A 2.4-GHz CMOS Class E cascode power amplifier (PA) for GSM applications in TSMC 0.18-μm CMOS technology present in this paper. Proposed Class E cascode PA topology is a single-stage topology in order to minimize the device stress problem. A parallel capacitor is connected across the transistors for efficiency enrichment also for dominating the effect of parasitic capacitances at ...

This paper presents an analysis of a reconstruction filter in a switched mode power amplifier system. Doubly and singly terminated filters for current-mode class-S power amplifiers were analysed previously through analytical, numerical, and experimental approaches, and it was shown that only singly terminated filters can fulfil the requirements of current-mode switching amplifiers, owing to the...