The linear theory and engineering design of the phase invariant controlled attenuator

On the base of the linear system theory a condition for minimum of the phase shift from attenuation in a voltage controlled attenuator (VCA) is founded. The base structure of the VCA is investigated. It is shown that fulfillment of the invariance condition provide a theoretically minimum of phase shift. For example, the paper disclosed details of the new attenuator design and discuss its performance. Its main difference from known consists in ultra broadband feature and large range of attenuation where minimum of the phase shift is reached at regulation. As a result of optimization, the correcting circuit parameters and adjusting parameters of diodes are founded.