Patent ID: 7420420

Claim:
A bias circuit for controlling a first field effect transistor comprising: a current-changing information circuit having a current-changing information signal output end; a voltage divider circuit having a voltage divider circuit signal input end and a voltage divider circuit signal output end; a first resistor having a first first resistor end and a second first resistor end; a first voltage source; a second voltage source; and a third voltage source; wherein said current-changing information circuit is connected to said second voltage source; said first first resistor end is connected to said current-changing information signal output end, this connection forming a node between said first resistor and said current-changing information circuit, said node acting as a voltage-changing information signal output end providing voltage-changing information; said second first resistor end is connected to said third voltage source; said voltage divider circuit is connected to said first voltage source; and said voltage divider circuit signal input end is connected to said voltage-changing information signal output end.