Abstract: A voltage ratio doubler circuit comprising an input node maintained at a constant input voltage V.sub.IN ; an output node at an output voltage V.sub.OUT ; and means, coupled between the input node and the output node, for selectively determining the ratio V.sub.OUT /V.sub.IN to equal either (a) a value K' or (b) a value K'/2 determined by impedances in the doubler circuit. In a first embodiment of the invention, the impedance of the load placed at the output node is matched with the system impedance of the doubler circuit. In this first embodiment, the input impedance, and hence the level of V.sub.IN at the input node does not vary regardless of which voltage ratio is selected. In a second embodiment, the load impedance and doubler circuit system impedance do not match. In this second embodiment, a leveller means is included. The leveller means provides a reference voltage V.sub.REF which varies with changes in input impedance at the input node. The reference voltage V.sub.REF is used to maintain V.sub.

Abstract: A programmable microwave card-type step attenuator is compensated for switch capacitance to render its attenuation response effectively insensitive to frequency over most of its dB range and comprises a plurality of cascaded attenuator sections disposed on a microstrip card with each attenuator section including a deposited film microstrip resistive network adapted to be switched into or out of the signal line by a miniature relay switch, a minimum loss transmission line being inserted into the signal line when the resistive network is switched out. Each of the microstrip resistive networks includes a reactive element connected thereto to compensate the frequency response of the resistive networks due to deviations from the optimum electrical length, thereby minimizing the frequency sensitivity of the attenuation characteristic of the section. Inductive effects are achieved by use of suitably shaped conductive areas or by removal of portions of the resistive networks.