无线电工程

发射机射频通道的增益会随温度变化而变化。通常在通道中加入射频可调衰减器,通过热敏电阻电路调节衰减器的控制电压或电流达到补偿射频通道增益变化的目的。针对星载设备小型化和低功耗的设计需求,提出了一种新型的温补方案:通过热敏电阻调节DAC的BIASJ引脚偏置电阻来控制DAC的输出功率(即射频通道的输入功率),从而实现发射机输出功率稳定的目的。对该方案进行了原理分析,并给出了设计方法。通过试验证明该方案合理可行。

The gain of RF channel in the transmitter varies at different temperatures. Generally,the adjustable RF attenuator is added in channel,and the thermistor circuit is used to adjust the control voltage or current of attenuator to compensate the RF channel gain variation at different temperatures.According to the design requirement of space-borne equipment's miniaturization and low power consumption,a new temperature compensation scheme is put forward. In this scheme,the thermistor is used to adjust DAC BIASJ pin bias resistor to control the output power of DAC( i.e.,input power of RF channel),and to realize stable output power of transmitter.The principle of this scheme is analyzed and the design method is put forward.The test results show that this scheme is reasonable and feasible.