| 摘要 |
PURPOSE:To obtain an internal matching element with low output impedance by composing an output matching circuit by a Chebyshev type lumped-constant circuit wherein source inductant and thermal resistance are reduced. CONSTITUTION:The electrodes 17, 18 of the third and the fourth lumped constant capacity for output matching circuit are provided on a high-dielectric substrate 16 on a metal plate 2 for grounding and the electrodes 17, 18 are connected 19, and the electrode 18 and a distributed constant line 10 are connected 20. The Chebyshev circuit of two-stage lumped-constant for output matching is formed by the electrode 17, wiring 19, electrode 18, and wiring 20 and a drain projected electrode 5 in a semiconductor chip 1 composed of flip chip constitution is directly fixed on the electrode 17 of the third lumped constant capacity. With the height of a convex section 6 fixed below the thickness of ceramic substrates 9, 12, parastic source inductance and thermal resistance by the convex section 6 can be reduced and the power gain of an element and 1dB compressed point output can be improved. And even if the output impedance is reduced by increasing the chip 1, the element can completely match with 50OMEGA. |
