平面慢波电极结构功率行波场效应器件的实验研究

正 (一)引言 近年来国内外对行波型场效应器件已开始注意研究,其原因是采用行波相互作用形式能使微波场效应管的性能有较大的改进。迄今国外的研究偏重于低电平超宽频带放大器的机理探讨,并在微波单片集成方面作了有成效的工作。然而应用行波作用原理来获得大功率输出方面,到目前还未见专文讨论。本工作主要根据行波互作用原理(见文献[4])设计了一个功率型行波场效应器件模型,并对此进行研究测试,取得一些

EXPERIMENTAL INVESTIGATION OF THE COPLANAR SLOW WAVE ELECTRODE TYPE POWER TRAVELLING WAVE FET

According to the recently developed travelling wave interaction concepts, a TW FET with suitable electrode structure for a monolithic realization has been designed and investi-gated by a microstrip line hybrid model together with individual FETs. A coplanar meander line slow wave electrode system was chosen, since it can be easily integrated into a monolithic FET structure. The active length of the model was 3 guided wave length long. With 21 individual FETs the output power of the model was higher by more than one order in magnitude as compared to an individual FET. A rather flat gain characteristic with broad-band-width of 1:15 was obtained. The small signal S parameters showed useful values. The RF field distribution along the active meander line electrodes was measured. The distribution reveals the TW interaction nature. The phase shift and two tone third order intermodulation with the input power level were also observed. No efforts had been spent to optimize the model design, but the measured characteristic was still attractives; there is much room for improvement in performance of the TW FET.