Amplifiers – Combined with automatic amplifier disabling switch means
Reexamination Certificate
1998-08-19
2001-02-13
Mottola, Steven J. (Department: 2817)
Amplifiers
Combined with automatic amplifier disabling switch means
C330S107000, C330S12400D, C330S20700P
Reexamination Certificate
active
06188277
ABSTRACT:
TECHNICAL FIELD
The present invention is generally directed to an RF power amplifier system for use in amplifying an RF input signal and is more particularly directed toward monitoring the system and providing protection for the system.
BACKGROUND OF THE INVENTION
RF power amplifier systems are known in the art for use in amplifying RF signals for broadcasting purposes including radio and television. Such power amplifiers may be employed in the broadcasting of either analog television signals, known as the NTSC, PAL, SECAM format, or digital signals, sometimes known as DTV format. When employed in television broadcasting, the frequency bandwidth for the television signals is 6 MHz. The television channels will be in the UHF signal range from approximately 470 to 860 MHz.
The RF input signal to such a power amplifier is obtained from an RF exciter and, for example, this may take the form of a modulated RF carrier within a frequency band of 470 to 860 MHz with the bandwidth of any one channel being on the order of 6 MHz. This modulated RF input signal may have a magnitude on the order of 20 milliwatts. This input signal is increased in magnitude to a much higher level such as on the order of 400 watts which represents a gain on the order of 43 dB.
These power amplifier systems are expected in many situations to be constantly operating so that a radio or television station employing such a power amplifier system may continuously broadcast.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, the power amplifier system for amplifying an RF input signal includes a modulator, such as a vector modulator, for receiving and modifying an input signal and providing therefrom a modified signal. The system includes at least one power amplifier the operation of which is monitored and the modulator is controlled in accordance with the monitoring.
In accordance with a more limited aspect of the present invention, the vector modulator includes a gain varying means for varying the gain of the input signal in response to the monitored operation of the power amplifier.
In accordance with a still further aspect of the present invention, the modulator includes signal phase varying means for varying the phase of the input signal in response to the monitoring of the operation of the system.
Also, in accordance with another aspect of the present invention, a power detector detects the RMS power of the input signal and compares this with a reference and the operation of the amplifying system is adjusted in accordance with that comparison.
In accordance with a still further aspect of the present invention, the average input power is determined and compared to the average output power and the modulator is adjusted in accordance with that comparison.
REFERENCES:
patent: 4794343 (1988-12-01), Yang
patent: 4859967 (1989-08-01), Swanson
patent: 5111166 (1992-05-01), Plonka et al.
patent: 5121077 (1992-06-01), McGann
patent: 5126704 (1992-06-01), Dittmer et al.
patent: 5157346 (1992-10-01), Powell et al.
patent: 5256987 (1993-10-01), Kibayashi et al.
patent: 5438683 (1995-08-01), Durtler et al.
patent: 5884143 (1999-03-01), Walkstein et al.
Borodulin Dmitriy
Cabrera George
Dittmer Timothy W.
Hu Zhiqun
Poggi Peter J.
Harris Corporation
Mottola Steven J.
Tarolli, Sundheim, Covell Tummino & Szabo L.L.P.
LandOfFree
Power amplifier having monitoring and circuit protection does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Power amplifier having monitoring and circuit protection, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Power amplifier having monitoring and circuit protection will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2593787