Generalized Theory and Realization of Continuously Loss-Programmable Bandpass Filtering Attenuators

In this article, a generalized theory of bandpass filtering attenuators (filtenuators) is proposed. A filtenuator is a device that combines the frequency-selective characteristics of a filter and the loss-programmable characteristics of an attenuator into a single component. The loss-programmable aspect of the filtenuator is based on the tuning of a p-network of resistances, which are implemented using p-i-n diodes to control the individual resistance values electronically. A loss-programmable, third-order Chebyshev bandpass filtenuator is designed, fabricated, and measured to verify the generalized theory. The filtenuator is designed to operate at 1 GHz and has a tunable attenuation range of 2-10 dB. This proposed filtenuator demonstrates the feasibility of a tunable, low-cost, size, weight, and power (C-SWaP) solution to increase radio frequency (RF) system dynamic range and a design process that allows for future development of filtenuators.