High-frequency circuit of reduced circuit scale
AssigneeAlps Electric Co., Ltd.
InventorMasaki Yamamoto
Life of this patent
Estimating the term…
Abstract
A high-frequency circuit is provided. In the high-frequency circuit, a first PIN diode is provided in a signal line and a second PIN diode is provided between the signal line and ground so that an attenuating circuit is formed. A power supply is applied to one end of a series circuit composed of two resistors. The other end of the series circuit is connected to ground via a drain-source path of an FET. An AGC voltage is applied to a gate of the FET. A bias voltage in accordance with the AGC voltage is applied to a base voltage of a low-noise amplifier via the first and second PIN diodes so as t control attenuation of the first PIN diode and an operating current of the low-noise amplifier.
Claims9
A high-frequency circuit comprising:
- a first PIN diode disposed in a signal line to which a high-frequency signal is introduced, one end of the first PIN diode on the high-frequency signal input side being connected to ground via a resistor;
- an amplifying device, an input end of the amplifying device being connected to the other end of the first PIN diode for a direct current;
- a bias circuit connected to the input end of the amplifying device;
- and
- a variable bias circuit to which a control voltage is supplied from a control voltage supply line, the control voltage being applied to the control voltage supply line in accordance with the signal level of the input high-frequency signal, the variable bias circuit generating a variable bias voltage in accordance with the control voltage and applying the variable bias voltage to the one end of the first PIN diode so as to control attenuation of the first PIN diode and control an operating current of the amplifying device.
A high-frequency circuit comprising:
- an attenuating circuit including a first PIN diode, the first PIN diode being disposed in a signal line to which a high-frequency signal is introduced;
- an amplifying device connected to a stage downstream of the attenuating circuit, the amplifying device including a feedback circuit;
- and
- a variable bias circuit to which a control voltage is supplied from a control voltage supply line, the control voltage being applied to the control voltage supply line in accordance with the input signal level of the high-frequency signal, the variable bias circuit generating variable bias voltages supplied to the first PIN diode and the feedback circuit in accordance with the control voltage, the variable bias circuit controlling attenuation of the first PIN diode using the variable bias voltage applied to one end of the first PIN diode and controlling an amount of feedback of the feedback circuit using the variable bias voltage applied to one end of a third PIN diode.
Dependencies are inferred from the claim text.