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A review is presented on the 94 GHz mixer diode development, conversion loss, and noise figure measurements. Balanced mixer results at 94 GHz are described using a successfully demonstrated broadband 3 dB directional coupler. Tunnel diodes were investigated as mixers, but were dropped when the results of welded junction diodes appeared to be much superior. The design of 200 to 400 MHz broadband amplifiers for use as preamps and post amplifiers is presented along with test data. The design of the 94 GHz solid state source is described. The transistor driver is designed to provide 16 watts at 290 MHz. The transistor driver or exciter consists of an oscillator at 72 MHz followed by a buffer, an amplifier-multiplier to 290 MHz, and two stages of power gain to achieve 20 watts. A varactor multiplier chain, consisting of six stages, follows the transistor driver. The six varactor stages chosen are: four triplers followed by two doublers. (Author)

On the basis of the results presented in this report it is believed that the use of varactor harmonic generators for the millimeter wave range has been proven practical. A 70 to 140 GHz doubler with an output of approximately 15 milliwatts has been demonstrated. Low frequency capacitance and resistance measurements and the 20% efficiency obtained in doubling from 70 to 140 GHz indicate that the cutoff frequency of the varactor is approximately 1000 GHz. Vibration tests were run on a number of diodes with only one failure. These tests consisted of both stepped and continuous changing frequencies from 10 to 60 Hz, with a G force of up to 7 G's at 60 Hz and 8.6 G's at 30 Hz. Conversion loss measurements were presented on 20 of the mixer diodes which had their IF ports modified for balanced mixer development. The average conversion loss of these 20 units was approximately 7.5 db or approximately 0.5 db better than the previously delivered 33 mixer diodes. The significance of this improvement was due to greater experience and not to any modifications in the mixer design. Some preliminary results were also presented on an RG-99 hybrid to be used in the balanced mixer. (Author)