发明名称 |
Active bias for a pulsed power amplifier |
摘要 |
A high-power radio-frequency amplifier act on periodic pulses of RF energy. The bias is controlled for each of a bank of FETs or other amplifier devices that constitutes the main power stage. A sample of bias current is obtained during a blanking period on the front porch of the RF gating period. Quiescent drain current is measured, and stored on a sample/hold circuit. A digital signal processor provides bias values that are sent via a D/A converter to biasing circuits that add the bias levels to the input RF signal. If the bias current is above or below a desired level, the stored bias level is decreased or incremented respectively. A timing control circuit gates the sample/hold circuit and switches in advance of the biasing circuits. The timing control circuit also creates a blanking signal to apply to an attenuator to produce a null region during the first 100 microseconds of the gating signal. A thermal sensor is coupled to one or more amplifying devices for presetting the operating voltage when operation has been interrupted for a predetermined period of time.
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申请公布号 |
US5451907(A) |
申请公布日期 |
1995.09.19 |
申请号 |
US19940243161 |
申请日期 |
1994.05.16 |
申请人 |
ENI, DIV. OF ASTEC AMERICA, INC. |
发明人 |
KEANE, ANTHONY R. A.;VANDEBROEK, BART C. |
分类号 |
H03F1/30;(IPC1-7):H03F1/30;H03F3/68 |
主分类号 |
H03F1/30 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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