| Research Abstract |
1. A broadban six-port magic junction (MJ) is developed by means of a compact matching element and an impedance-step adapted to the coaxial line (the bandwidth is about 1 GHz).
2. A power combining system of six oscillators coupled through the above MJ and three small-sized magic T's (MT) is described. When the circular arm of MJ and the H-plane arm of each MT are terminated in a circuit having a reflection coefficient with the amplitude of 3.3 - 0.6 and the phase of , the outputs of the six oscilators completely combine in a load at the coaxial arm of MJ.
3. A GUNN@-diode mounting structure possible of loading four diodes is newly proposed. Design equations of a 4N-device oscillator consisting of a series connection of N mounts are given also. Moreover, power-combining efficiencies of 95.1 percent, 94.3 percent, and 88.3 percent are experimentally obtained with 8-, 16-, and 24-device oscillators, respectively.
4. A power-combining efficiency of 85.5 percent (99.6 percent for only MT) is obtained form a 48-device oscillator system constructed of two 24-device oscillators coupled through MT.
5. Finally, a 144-device (ultramultiple-device) oscillator system is assembled from six 24-device oscillators, MT, and MJ, and an output power of 3.8 W is achieved with a power-combining efficiency of 78.9 percent (a dc-RF conversion efficiency of 1.96 percent). As was expected, this combined output power is more than one hundred times (exacly 113 times) as large as the average output of the single device (33.5mW).
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