transfer matrix method (tmm) has been applied to analyze characteristics of semiconductor laser optical amplifiers. the input signal is sinusoidal modulating wave and we do not assume the modulating bias signal as well. we have shown that the distoration arises from gain modulation at low modulation frequencies, but in microwave modulation frequencies, the gain takes an average value and the re...

Optical amplifiers make the communication system transparent from the beginning to the end, in contrast to conventional repeater-type systems. This poses new challenges for the performance of all system components, including the optical amplifier. As a consequence, optical amplifiers need to be most thoroughly tested before their deployment. This paper discusses methods and instruments for meas...

The new Ka-band communications services require highly linear, high power amplifiers (HPAs). Traveling wave tube amplifiers (TWTAs) offer the best millimeter wave HPA performance in terms of power and efficiency, but are inferior to solid state power amplifiers (SSPAs) in linearity. This paper discusses techniques for improving millimeter wave HPA linearity. The significance and methods for eva...

We report traveling-wave amplifiers having 1–112 GHz bandwidth with 7 dB gain, and 1–157 GHz bandwidth with 5 dB gain. A third amplifier exhibited 5 dB gain and a 180GHz high-frequency cutoff. The amplifiers were fabricated in a 0.1m gate length InGaAs/InAlAs HEMT MIMIC technology. The use of gate-line capacitive-division, cascode gain cells and low-loss elevated coplanar waveguide lines have y...

Several new CMOS very high DC-gain amplifiers that use internal positive-feedback techniques are presented. These amplifiers have a controllable gain and don't require perfect matching of transistors to achieve the high DC gain. An implementation of a sample and hold circuit constructed using one of the proposed amplifiers is described. Sin~ulation results predict a DC gain larger than lOOdB is...

Orthogonal Frequency Division Multiplexing (OFDM) is a method of Digital Modulation in which a signal is split into several narrowband channels at different frequencies. The OFDM technology was first conceived in the 1960s and 1970s during the research into minimizing interference among the channels near each other in the frequency [5]. The main idea behind OFDM is that since lowrate modulation...