Device Of GAAS Microwave Power Fet Under High Frequence

The internal matching technology of GaAs microwave power FETs was mainly studied under high frequency, which was mainly applied in semiconductor power devices. Now this technology has been industrialized after a few years of research, but at the frequency 14.5-15GHz only the max power 10W GaAs device could be for sale and the laboratorial device maybe has higher power. The high efficiency and high reliable device has not been developed up till the present moment in domestic because the Ku-wave-band power device research was always difficulty.The theory of the internal matching technology was used to obtain the phase balance between each dies and passive circuits, and transform the input and output impedance of the dies to the appropriate impedance, then combine and split the power of these dies. In this rationale, the active model of the device and the passive model of the matching-network'components were studied, which avoided the blindness evidently and reduced the designing periods. During the design process, the low dielectric porcelain material was introduced in the capacity, which reduced the debugging sensitivity and was possible to obtain the better matching condition, and promoted the microwave performance finally. The tapered transmission line designed by the ADS software tools removed the coupling between the lines, achieved the more simple structure and the lower transmission loss compared with theλ/4 transmission line. Lastly the improvement on the testing tools and the package promoted the microwave performance of the device.Depended on the improvements of the upper aspects, the internal matching device was developed in the Ku-wave-band. The microwave testing results was shown as follows under A class condition: while the drain supply voltage was at 8V, the device delivered a saturation output power more than 40.4 dBm(11W), a power gain of 7dB and a power added efficiency more than 23% between the frequency of 14.5 GHz and 15 GHz.