Switchable Reflective Excitation Method for Rapid Characterization of Monopulse Comparators

In high-precision tracking radars, the angular resolution depends critically on the amplitude and phase balance of the monopulse comparator. However, accurately and efficiently characterizing this highly integrated microwave component remains challenging, as its complex structure and high port count increase the difficulty of microwave testing. To achieve rapid measurement without compromising accuracy, this paper presents a novel characterization technique utilizing switchable reflective excitation signals. By employing the inherent reflected signals as internal excitation sources, this physical innovation allows for the simultaneous multiport input of a four-horn comparator. In addition, a switchable calibration window and a multiport matched load were designed to precisely control the boundary conditions directly at the reference plane of the device under test (DUT). Experimental validation on an X-band waveguide monopulse comparator demonstrates that the proposed methodology can promptly extract the intrinsic device characteristics. Good agreement between the theoretical predictions and measurement results confirms that the proposed technique provides a rapid and robust diagnostic solution for microwave measurement of monopulse comparators.