| 摘要 |
PURPOSE:To improve the durability by eliminating mechanical changeover and to enhance the switching speed. CONSTITUTION:A PIN diode 15 is provided between an input terminal 11 and an output terminal 12 and a feeding circuit A to supply a DC bias current in the forward polarity is provided. The feeding circuit A is made up of a series connection circuit comprising a DC power supply 20, a current limit resistor 21, and choke coils 22, 23 interrupting a high frequency signal. Since a DC current flows to a choke coil (bypass circuit) 53 when a high frequency unit 50 is connected, the PIN 15 is in the OFF state and the high frequency signal does not pass the PIN 15 but passes through the high frequency unit 50. On the other hand, when the high frequency unit 50 is removed, the DC current flows to the PIN 15. Then the PIN 15 is in the ON state and the high frequency signal passes through the PIN 15.
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