An Impedance Transforming Transistor Mounting Structure for Amplifiers in Fin-Line Technique

A novel impedance transforming transition between a fin-line and an unbalanced line was used to develop a new mounting structure to characterize FETs in fin-line technique. In the frequency range of 9...12 GHz measured S-parameters are compared with data sheet values. Based on these data the rigorous design of a low noise amplifier with matching circuits in fin-line technique is presented avoiding the necessity of tuning. The measured noise figure at 10 GHz was less than 2 dB with an associated gain of 9.7 dB. Because the mounting structure can be scaled to higher frequencies, transistors can utilize the superior properties of fin-lines in the higher mm-wave range.