Compact Amplitude-Monopulse Microstrip Antenna Design for Wide Field-of-View Direction Finding

We investigate the challenges and possibilities to design short microstrip leaky-wave antennas (MLWA), which synthesize amplitude-monopulse patterns covering a wide angular field of view (FoV). It is shown that the standard design methodology requests the MLWA to operate in a radiation regime associated to a high scanning angle associated to poor radiation efficiency. Subsequently, we propose a new design technique to operate in a more relaxed dispersion regime, where the antenna is radiating close to broadside. Designs examples working in the 2.45 GHz band are reported to validate the novel methodology, demonstrating the successful synthesis of monopulse patterns covering a wide FoV of 120° using a MLWA of length 9.8 cm (0.8 wavelengths). To the authors' knowledge, this is the most compact design and the widest FoV reported for this class of monopulse antennas, which might find useful application for integrated antenna sensors in the context of the Internet of Things.