Title :
A basic concept to reduce the frequency distortion of distributed amplifiers
Author_Institution :
Inst. fur Hochfrequenztech., Tech. Hochschule Darmstadt
fDate :
7/1/1990 12:00:00 AM
Abstract :
It is shown that a frequency-independent attenuation and wave impedance can be obtained for relatively lossy transmission lines. The approach is based on a concept for avoiding dispersive distortions on telecommunication lines by introducing distortion-free lines. A derivation shows that the attenuation and characteristic impedance become frequency-independent of the conductance, G≐ is increased so that R´/L´=G´/C´. This can be done by modifying the bias until the correct value of G´ is obtained. This is particularly true when transistors which provide through their structure (such as doping profiles) the capability of fine-tuning the RF input currents, possibly by means of additional electrodes, are employed
Keywords :
electric distortion; microwave amplifiers; solid-state microwave circuits; RF input currents; bias; characteristic impedance; distributed amplifiers; doping profiles; fine-tuning; frequency distortion; frequency-independent attenuation; lossy transmission lines; wave impedance; Attenuation; Attenuators; Bandwidth; Distributed amplifiers; Distributed parameter circuits; Frequency; Impedance; Microwave integrated circuits; Phase shifters; Propagation losses;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on