JPS57118412A - High-frequency power amplifier - Google Patents
High-frequency power amplifierInfo
- Publication number
- JPS57118412A JPS57118412A JP469881A JP469881A JPS57118412A JP S57118412 A JPS57118412 A JP S57118412A JP 469881 A JP469881 A JP 469881A JP 469881 A JP469881 A JP 469881A JP S57118412 A JPS57118412 A JP S57118412A
- Authority
- JP
- Japan
- Prior art keywords
- power
- supplied
- circuit
- reflected
- amplifiers
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03G—CONTROL OF AMPLIFICATION
- H03G3/00—Gain control in amplifiers or frequency changers
- H03G3/20—Automatic control
- H03G3/30—Automatic control in amplifiers having semiconductor devices
- H03G3/3036—Automatic control in amplifiers having semiconductor devices in high-frequency amplifiers or in frequency-changers
- H03G3/3042—Automatic control in amplifiers having semiconductor devices in high-frequency amplifiers or in frequency-changers in modulators, frequency-changers, transmitters or power amplifiers
Landscapes
- Control Of Amplification And Gain Control (AREA)
Abstract
PURPOSE:To realize a system which can protect a transistor of output stage with sufficient redundancy for a high-frequency power amplifier which is converted to a transistor, by controlling the output power based on the reflected power given from a load. CONSTITUTION:The high-frequency power to be applied to an input terminal 16 is amplified up to the level set by a manual control variable resistor 14 at a control part 3 by a variable gain amplifier 1 to be supplied to a power amplifying part 2. The power is supplied through the part 2 to power amplifiers 5-7 via a distributor 4. The outputs of these amplifiers are synthesized in terms of electric power by a synthesizer 8 to be supplied to a load 20. The reflected power is detected by a directional coupler 16 of the amplifiers 5-7 and changed into a direct current through a wave detector 17 to be supplied to a maximum value detecting circuit 9. In case the reflected power is small, the detected voltage at the part 2 is isolated from a control circuit 12. The detected voltage is applied to the circuit 12 by a comparator 10 and via a switch circuit 11 to reduce the gain of the amplifier 1 in case the reflected voltage increases and the output voltage of the circuit 9 exceeds the level set by a working level controller 13.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP469881A JPS57118412A (en) | 1981-01-14 | 1981-01-14 | High-frequency power amplifier |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP469881A JPS57118412A (en) | 1981-01-14 | 1981-01-14 | High-frequency power amplifier |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS57118412A true JPS57118412A (en) | 1982-07-23 |
Family
ID=11591102
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP469881A Pending JPS57118412A (en) | 1981-01-14 | 1981-01-14 | High-frequency power amplifier |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57118412A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0199116A (en) * | 1987-10-12 | 1989-04-18 | Fujitsu Ltd | How to control high frequency power supply |
| US6329880B2 (en) | 2000-02-02 | 2001-12-11 | Nec Corporation | Radio frequency transmitting circuit |
| KR101197032B1 (en) | 2009-12-08 | 2012-11-06 | (주) 인티그럴 | Protection circuit for high power amplifiers |
-
1981
- 1981-01-14 JP JP469881A patent/JPS57118412A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0199116A (en) * | 1987-10-12 | 1989-04-18 | Fujitsu Ltd | How to control high frequency power supply |
| US6329880B2 (en) | 2000-02-02 | 2001-12-11 | Nec Corporation | Radio frequency transmitting circuit |
| KR101197032B1 (en) | 2009-12-08 | 2012-11-06 | (주) 인티그럴 | Protection circuit for high power amplifiers |
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