THE DIELECTRIC-FILLED PARABOLA - A NEW MILLIMETER SUBMILLIMETER WAVELENGTH RECEIVER TRANSMITTER FRONT END

A design is presented for a semi-integrated millimeter/sub-millimeter wavelength receiver/transmitter front end incorporating a planar antenna and a solid-state device in an efficient feed structure which can be matched directly to high f-number optical systems. The new feed system combines the simplicity and robustness of a dielectric substrate lens with the high gain of a parabolic reflector in a single structure that we have termed a dielectric-filled parabola. The same fundamental unit can be configured as either a heterodyne or direct detection mode receiver, a power transmitter or a frequency multiplier by changing out the solid-state device and/or the integrated antenna. The structure can also be used with a small integrated antenna array in a multibeam or imaging arrangement. In the first part of the paper, design and fabrication details for the new feed system are given. These are followed by beam pattern and impedance measurements taken on a microwave model when dipole, bow-tie, log-periodic and log-spiral antennas are used as the integrated feed elements.