| 摘要 |
PURPOSE:To widen the band of matching characteristics and to realize adaption to the input matching of a microwave integrated circuit by using the emitter input impedance of a transistor (TR) as the impedance for matching an amplifier circuit input. CONSTITUTION:An emitter input circuit for a TR consists of resistances 16, 17, and 20, and a TR19. When its input impedance is Rin2 and the input impedance of a TR8 is Rin1, the total input impedance is the parallel impedance of Rin1 and Rin2. The current amplification factors of both TRs are almost equalized to each other, resistances 9 and 20 are set sufficiently large, and resistances 16 and 17 have proper values. Then, Rin1>>Rin2 and the total input impedance Rin is equalized to Rin2. Consequently, matching is possible as to even a low-impedance signal source and a transmission line, and the purpose is attained. |
