Design of a Symmetric Lumped-Element Bandpass Filtering Attenuator (Filtenuator)
Jonathan M. Knowles, Hjalti H. Sigmarsson, Jay W. McDaniel
Abstract
This paper presents a novel filtering attenuator (filtenuator) concept, which allows for adjustable passband attenuation and filtering characteristics in a single design. The mathematical equations relating the desired passband loss to required resistance values are provided and validated with ideal circuit simulations. A third-order Chebyshev static filtenuator is designed at 1 GHz with multiple values of attenuation using lumped-element components as a proof of concept. Simulated and measured results for a 3 dB filtenuator show good agreement and several attenuation levels are shown to validate the concept. The proposed static filtenuator has advantages of ease of modification, compact size, and low cost, which are necessities in meeting the needs of reducing cost, size, weight, and power (C-SWaP) in future radio frequency transceivers.