| 摘要 |
<P>PROBLEM TO BE SOLVED: To easily obtain desired characteristics using a temperature variable resistor with a negative temperature coefficient which causes no deterioration of V.S.W.R even at a high frequency, and has good availability. <P>SOLUTION: Two first delay circuits 14 comprising a line having a length of almost λ/4 is connected in series to transmission lines 1, second delay circuits 15 comprising a line having a length of almost λ/4 are connected to both ends of these first delay circuits 14, and a temperature variable resistor 17 comprising a thermister 16 having a negative temperature coefficient and a fixed resistor 5 is connected between the second delay circuit 15 and the ground. That is, two sets of π type circuit composed of the first delay circuit 14, a pair of the second delay circuits 15, and a pair of the temperature variable resistors 17 are disposed, and four thermistors 16 having the same negative temperature coefficients are used. Thereby, a reactance component produced by the thermistor 16 is cancelled by the π type circuit, and V.S.W.R can be maintained at an excellent value. <P>COPYRIGHT: (C)2012,JPO&INPIT |
