| 摘要 |
PURPOSE:To attain a prescribed performance by means of shield, by arranging >=2 circuit parts among an input circuit part, a mixing part, and a local oscillator part in the 1st and the 2nd frequency converting sections on separate printed wiring boards. CONSTITUTION:In a frequency converter, shield plates 20A, 20B are erectly provided to constitute an up-converter section 21 and a down-converter section 22. The converter section 21 consists of an input BPF section 23, the 1st mixer 24 and the 1st local oscillator section 25, and these circuit sections 23-25 are mounted on separate split printed wiring boards 23A-25A, respectively. These wiring boards 23A-25A are constituted to provide erectly shield plates 26, 27 for the shield. Through the constitution in this way, the leakage of the oscillating component of an oscillator 25 or the invasion of various disturbing signal induced in an input terminal 28 is prevented. |
