| 摘要 |
A phase shifter includes two phase shift circuits connected in parallel with each other between an input terminal for a signal of a voltage ei and ground and each consisting of a series circuit of a resistor and a capacitor, first and second differential amplifiers for receiving at their first terminals voltages e1 and e2 of junctions between the resistors and the capacitors of the phase shift circuits and for receiving input signals at the second input terminals, the collectors of noninverting and inverting transistors of the first differential amplifier being connected to the collectors of inverting and noninverting transistors of the second amplifier, respectively, thereby obtaining a vector sum e0 of e1 and e2, and a third differential amplifier consisting of two transistors having the first and second differential amplifiers as loads at their collector sides, respectively, and capable of arbitrarily changing a phase shift between the input signal ei and the output signal e0 in accordance with a voltage difference between the signals supplied to the bases of the two transistors. |
