Device and method for reducing gain temperature excursion of emitter

Abstract

The invention provides a device and a method for reducing gain temperature drift of an emitter. The device comprises an input port, an operational amplifier, a first NMOS (N-channel Metal Oxide Semiconductor) tube, a second NMOS tube, a power port, a constant current source, a load and an output port, the inverting input end of the operational amplifier is connected with the input port; the grid electrode of the first NMOS tube and the grid electrode of the second NMOS tube are connected with the output end of the operational amplifier. The drain electrode of the first NMOS tube and the positive electrode of the constant current source are connected with the in-phase input end of the operational amplifier. The source electrode of the first NMOS tube and the source electrode of the second NMOS tube are both grounded; the negative electrode of the constant current source and the first end of the load are connected with the power port. The second end of the load and the drain electrode of the second NMOS tube are connected with the output port. According to the invention, the adaptability of the device is improved while the gain temperature excursion of the emitter is reduced.

Description

technical field [0001] The present invention relates to the technical field of wireless communication, in particular, to a device and method for reducing transmitter gain temperature drift. Background technique [0002] In wireless communication, the transmission power directly affects the communication distance. When the temperature changes, if the transmission output power changes greatly, the maximum transmission power will definitely exceed the power required by the system, which will bring electromagnetic compatibility problems and additional power consumption problems. Therefore, the chip should reduce the temperature drift change of the output power of the transmitting channel as much as possible. In order to reduce the temperature drift change of the output power of the transmitting channel, some methods use PTAT current or negative temperature coefficient feedback resistors in the amplifier tube to increase the transconductance of the amplifier tube at high tempera...

AI Technical Summary

Problems solved by technology

But when using PTAT current, to fully compensate the gain change, the slope of PTAT needs to be very high, so at low temperature, the lower current will cause the linearity of the circuit to deteriorate

When a resistor with source-level negative feedback is used, the gain of the amplifier will be reduced, and the current of the amplifier tube needs to be increased, thereby increasing power consumption. In addition, because the gain temperature drift needs to be compensated by the temperature coefficient of the resistor, it will actually be limited by the process. At the same time, Satisfying gain and low temperature drift can result in very large power dissipation

When using the ratio of different temperature coefficients, it may not be possible to find a resistor with a suitable temperature coefficient in the selected process. This method may not be suitable for all processes.

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