MMIC FAMILY FOR DBS DOWN-CONVERTER WITH PULSE-DOPED GAAS-MESFETS

A monolithic microwave integrated circuit (MMIC) family was demonstrated as a low-noise block down-converter (LNB) for use in direct broadcast satellite (DBS) receivers operating from 11.7 to 12 GHz. A 12-GHz low-noise amplifier (LNA), a 12-GHz mixer (MIX), a 10.7-GHz dielectric resonator oscillator (DRO), and a 1-GHz IF amplifier (IFA) were designed with GaAs MMIC technology. This is the first report of MMIC's for an LNB with pulse-doped GaAs MESFET's as the active elements. These MMIC chips were designed to form a complete LNB function with the exception of the dielectric resonator. The most significant result of this work is that practical low-noise performance can now be achieved without the use of high electron mobility transistors (HEMT's) in a preceding stage of the MMIC LNB. Almost noise-free satellite broadcast TV pictures were seen by using a parabolic antenna, 40 cm in diameter, without needing any additional circuit adjustment.