| 摘要 |
The basic module of a microwave Travelling-Wave Hybrid Junction amplifier (TWHJ) consists of a hybrid junction (0 DEG , 180 DEG or 90 DEG hybrid) combined with an appropriate phase-shifting element ( pi /2 element is needed for 0 DEG and 180 DEG hybrids and no element is needed for a 90 DEG hybrid) and three negative conductance circuits terminating three ports of the modified hybrid while the fourth port serves as an input-output port. Because of proper stabilization and matching, the negative conductance circuits are not oscillating but are acting as reflection type amplifiers. Any RF energy applied to the input port of the hybrid is multiply reflected while travelling through the hybrid giving rise to amplified RF energy emerging from the input port of the hybrid junction. Under ideal conditions, the power amplification of the TWHJ amplifier is the product of the power amplifications of individual negative conductance circuits and the saturated output power of the amplifier is equal to the saturated output powers of the circuits adjacent to the output port. The TWHJ amplifier can be extended in a modular fashion to any number of negative conductance elements to achieve the desired power amplification and saturated output power.
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