Patent ID: 6671502
Filing Date: 2003-12-30
Classification: H03G,H04B

Abstract:
A control device comprising:an input section which inputs a predetermined signal; an amplification section of a variable gain type which amplifies said predetermined signal; and a feedback loop which inputs a signal output from said amplification section and adjusts a gain of said amplification section to keep said output signal constant; wherein said amplification section comprises an amplifier of a fixed-gain type and an attenuator in which an attenuation amount is changed according to a signal from said feedback loop; and wherein said attenuator has an attenuation element including a PIN diode, a first resistance element having a first end and a second end, said first end connected with a previous stage of said attenuation element and said second end connected with a first voltage, and a second resistance element having a third end and a fourth end, said third end connected with a previous stage of said attenuation element and said fourth end connected with a second voltage.