Patent ID: 7030938

Claim:
A tuner apparatus comprising: a first tuner portion for receiving a first broadcast wave and outputting first transport stream data achieved by multiplexing encoded data, on sounds and/or pictures contained in the first broadcast wave; and a second tuner portion for receiving a second broadcast wave different from the first broadcast wave and outputting second transport stream data achieved by multiplexing encoded data on sounds and/or pictures contained in the second broadcast wave, said first and second tuner portions being provided on a circuit board, wherein said first tuner portion is provided on one surface of said circuit board and said second tuner portion is provided on a reverse surface of said circuit board, wherein a first wire pattern for transmitting the first transport stream data is formed on the surface of said circuit board on which said first tuner portion is provided, and a second wire pattern for transmitting the second transport stream data is formed on the reverse surface of said circuit board on which said second tuner portion is provided, wherein said circuit board has a first wire pattern layer on which said first wire pattern is formed, a second wire pattern layer on which said second wire pattern is formed, and an insulating layer sandwiched between said first wire pattern layer and said second wire pattern layer, and at least one ground layer for intercepting undesired radiation noises of said first tuner portion and said second tuner portion formed on said insulating layer, and wherein said ground layer has a first ground layer formed so as to confront said first wire pattern layer so that a first insulating layer corresponding to a part of said insulating layer is sandwiched between said first ground layer and said first wire pattern layer, and a second ground layer formed so as to confront said second wire pattern layer so that a second insulating layer corresponding to a part of said insulating layer is sandwiched between said second ground layer and said second wire pattern layer, said first ground layer and said second ground layer being confronted to each other so that a third insulating layer corresponding to a part of said insulating layer is sandwiched therebetween, whereby said circuit board is formed as a four layered circuit board having said first wire pattern layer, said second wire pattern layer, said first ground layer and said second ground layer.