Integrated Q-band MMIC diffraction grating transmitter

An integrated MMIC diffraction grating antenna has been developed which provides an electronic beam scanning capability at mm-wave frequencies. The grating antenna has been designed to operate near the second Bragg diffraction condition using a corrugated ceramic structure. To provide frequency scan capability, a GaAs varactor-controlled oscillator/buffer amplifier MMIC is employed as a source. As the frequency changes, the beam scans. A planar launch to the dielectric corrugated antenna has been developed to provide a low-cost, easy to manufacture interface from the mm-wave monolithic integrated circuit. The measured 3 dB beamwidth from a 10-period grating at 39 GHz is 5 degrees. Angular scan capability is 15 degrees/GHz.