VARIABLE GAIN AMPLIFIER

• Main Authors: HAMADA YASUSHI, NOSAKA HIDEYUKI
• Format: Patent
• Language: English; Japanese
• Published: 17.10.2019
• Subjects: BASIC ELECTRIC ELEMENTS; BASIC ELECTRONIC CIRCUITRY; CONTROL OF AMPLIFICATION; DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TOANOTHER; ELECTRICITY; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE; WAVEGUIDES

To provide a variable gain amplifier capable of giving a gain variable function to a power amplifier without lowering the output power of the power amplifier.SOLUTION: A gain adjustment part 102 which is constituted of a distribution switch 6 having a control terminal PC is provided to the input part of an amplifier circuit 101. A first end of a coupler CP is connected to an output line of the amplifier circuit 101, a second end of the coupler CP is connected to the anode of a diode D1, and to the cathode of the diode D1, a monitor terminal PM is connect via a low pass filter PLF1. The anode of the diode D1 is unbiased (ground potential=0 volt).SELECTED DRAWING: Figure 6 【課題】パワーアンプの出力電力を下げることなく、パワーアンプに利得可変機能を持たせる。【解決手段】増幅回路１０１の入力部に制御端子ＰＣを有する分布スイッチ６からなる利得調整部１０２を設ける。カプラＣＰの一端を増幅回路１０１の出力ラインに接続し、カプラＣＰの他端をダイオードＤ１のアノードに接続し、ダイオードＤ１のカソードに低域通過フィルタＰＬＦ１を介してモニタ端子ＰＭを接続する。ダイオードＤ１のアノードは無バイアス（接地電位＝０ボルトに設定）とする。【選択図】 図６