A Novel Frequency Reconfigurable Real-Time RF Edge Detector

In this paper, a frequency reconfigurable RF edge detector is presented to sense the edge of signal in its real time. The proposed circuit consists of a tunable 180° hybrid coupler and a tunable delay line, and theory analysis is carried out to find their relation. The delay line connects coupling port and isolation port to achieve a closed loop resonator across all frequency tunning range, which enables edge detection of RF signal in wide frequency range. To prove the design concept, a prototype of tunable microwave edge detector (TED) has been designed, fabricated, and tested, and the measured results match well with simulation and theory. By applying two-channel control voltage, the prototype senses edge of modulated RF pulse signal from 1.9GHz to 2.4GHz in real time.