IMPEDANCE CONVERTER CIRCUIT

摘要

PURPOSE:To facilitate the change of the stub attaching position and the stub length. CONSTITUTION:With regard to an input impedance converter circuit 12, a ground surface 33 is formed on the surface of a microstrip line 22 where a strip conductor 21 is formed. The surface 33 is connected to an earth conductor 19 via a through hole 34. A chip type stub 31 is attached onto a proper position of a dielectric substrate 18. The stub 31 consists of a dielectric layer formed on the bottom surface of a microstrip line 22. Then one of both ends of a strip conductor 21 of the line 22 and a ground conductor 19 are connected to the proper positions of the conductor 21 and the surface 33 respectively. The impedance of a terminal 11 is matched with the input impedance of an FET 13 by adjustment of the connecting position of the conductor 21, by adjustment of the selection of stubs 31 of different lengths of the line 22 or by selection of the stubs 31 of different lengths.