| 摘要 |
PURPOSE:To obtain an economical multiband electronic switching circuit, by providing a common active element for oscillation, a barrier cap, oscillating coils corresponding to the number of bands, and a switching element for connecting the barrier cap to this coil. CONSTITUTION:When DC voltage is applied to an (MW+B) terminal, transistors 115B, 112B are turned on. Also, a switching element 104B is biased in the forward direction and conducts by a coil 105B, a resistance 106B, the switching element 104B, a resistance 117, and a bus of a coil 118. Accordingly, oscillation is executed by frequency decided by a barrier cap 102 whose capacity is changed by an oscillating coil 110B, capacitors 107B, 108B and 109B, and tuning voltage. In this case, in order to supply the bias to a switching element 104, coils 105, 118 are used. In this way, this circuit uses 1 piece of active element for oscillation 119 and the barrier cap 102, and the oscillating coil corresponding to the band is prepared only by the number of bands, therefore, it becomes very economical. |
