@conference {19_URSI_EDUARDO_MONOPULSO_DIF_BONDING, title = {Diffusion-bonded circularly polarized W-band monopulse array antenna}, booktitle = {Simposium Nacional URSI 2019}, year = {2019}, month = {September}, abstract = {A W-band circularly polarized antenna array with monopulse capability has been designed and fabricated by diffusion bonding of copper plates. The antenna is presented as a proof of concept for a space debris radar project. A waveguide monopulse beamforming network provides monopulse operation in the two main radiation planes. The feeding network is implemented in waveguide technology as well, with corporate topology and amplitude tapering to ensure adequate radiation patterns for the monopulse system. Circular polarization is straightforwardly achieved by hexagonal-shaped radiating cavities. Experimental results validate diffusion bonding for complex multilayer antenna fabrication at W-band, providing a bandwidth over 10\% for axial ratio under 3 dB, impedance matching under -10 dB and total efficiency over 75\%.}, author = {E Garcia-Marin and J L Masa-Campos and P Sanchez-Olivares} }