Patent ID: 7525396
Filing Date: 2009-04-28
Classification: H03F,H04B

Abstract:
1. A hot standby system for radio frequency (RF) power amplifier, comprising: a primary RF power amplifier; an auxiliary RF power amplifier; and two single pole double throw (SPDT) microwave switches: a first SPDT microwave switch and a second SPDT microwave switch; wherein the two SPDT microwave switches each comprises a combining port, a first shunt port and a second shunt port; the combining port of the first SPDT microwave switch is a signal receiving end; the first shunt port of the first SPDT microwave switch is connected to the input port of the primary RF power amplifier; the second shunt port of the first SPDT microwave switch is connected to the input port of the auxiliary RF power amplifier; the combining port of the second SPDT microwave switch is the signal export end; the first shunt port of the second SPDT microwave switch is connected to the output port of the primary RF power amplifier; the second shunt port of the second SPDT microwave switch is connected to the output port of the auxiliary RF power amplifier; when the primary RF power amplifier functions properly, a signal inputted from the combining port of the first SPDT microwave switch is transmitted through the first shunt port of the first SPDT microwave switch to the input port of the primary RF power amplifier; after amplified by the primary RF power amplifier, the signal is transmitted to the first shunt port of the second SPDT microwave switch and then to the combining port of the second SPDT microwave switch; when the primary RF power amplifier fails, a signal inputted from the combining port of the first SPDT microwave switch is transmitted through the second shunt port of the first SPDT microwave switch to the input port of the auxiliary RF power amplifier; after amplified by the auxiliary RF power amplifier, the signal is transmitted to the second shunt port of the second SPDT microwave switch and then to the combining port of the second SPDT microwave switch; wherein the two SPDT microwave switches each further comprises seven transmission lines: a first, a second, a third, a fourth, a fifth, a sixth and a seventh transmission line and three switch devices: a first, a second and a third switch device; wherein the combining port of the first SPDT microwave switch is connected to the first ends of the fourth transmission line, the first transmission line and the second transmission line; the second end of the fourth transmission line is connected to the first ends of the sixth transmission line and the seventh transmission line, and the third switch device is installed between the ground and the junction of the fourth transmission line, the sixth transmission line and the seventh transmission line; the second end of the second transmission line is connected to the first end of the fifth transmission line, and the second switch device is installed between the ground and the junction of the second transmission line and the fifth transmission line; the second end of the fifth transmission line is connected to the second end of the seventh transmission line, and the junction of the fifth transmission line and the seventh transmission line is connected to the first shunt port; the second end of the first transmission line is connected to the first end of the third transmission line, and the first switch device is installed between the ground and the junction of the first transmission line and the third transmission line; the second end of the third transmission line is connected to the second end of the sixth transmission line, and the junction of the third transmission line and the sixth transmission line is connected to the second shunt port; when a signal is inputted from the combining port, the first and the third switch devices are closed, and the second switch device is open, the input signal reaches the first shunt port through the second and the fifth transmission lines; when a signal is inputted from the combining port, the second and the third switch devices are closed, and the first switch device is open, the input signal reaches the second shunt port through the first and the third transmission lines; when a signal is inputted from the combining port, the first and the second switch devices are closed, and the third switch device is open, the input signal is divided into two signals after passing through the fourth transmission line, one of the two signals reaches the first shunt port through the seventh transmission line and the other signal reaches the second shunt port through the sixth transmission line; when a signal is inputted from the first shunt port, the first and the third switch devices are closed, and the second switch device is open, the input signal reaches the combining port through the fifth and the second transmission lines; when a signal is inputted from the second shunt port, the second and the third switch devices are closed, and the first switch device is open, the input signal reaches the combining port through the third and the first transmission lines; when two signals are inputted from the first and the second shunt ports respectively, the first and the second switch devices are closed, and the third switch device is open, the two signals are combined at the junction of the seventh and the sixth transmission lines after passing through the seventh and the sixth transmission lines respectively, and the combined signal reaches the combining port through the fourth transmission line.