2–8 GHz Interference Detector With 1.1 μs Response

Abstract

This letter reports the first wideband method that: 1) detects both the power and frequency of an arbitrary interferer within a two-octave bandwidth and 2) subsequently deactivates the interferer through a frequency-tunable narrowband bandstop filter (BSF). The entire process can be completed within approximately <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1~\mu \text {s}$ </tex-math></inline-formula> . The success of the proposed detection method relies on creating frequency- and power-dependent standing wave patterns of the incoming signal. It is worth emphasizing that all frequencies and power levels are simultaneously mapped to the system’s detection scheme without requiring time-consuming spectrum- and/or power-searching steps. After presenting the fundamental concept and the basic design steps, we demonstrate a proof-of-concept system that can detect interfering signals with unknown and arbitrary frequencies in the 2–8 GHz band and powers in the −5 to +15 dBm range. The proposed system is implemented with low-cost off-the-shelf components. The measured interferer deactivation response time is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.1~\mu \text {s}$ </tex-math></inline-formula> for all signals within the system specifications.