Multi-switching circuit of low noise frequency converter (LNB) with low power consumption and frequency characteristics

摘要

This study involves a multifunctional switch LNB (low noise frequency converter) which can receive the polarization signal in the outdoor unit lnob of the satellite broadcast receiver at the same time. More specifically, it is a multifunctional switching circuit which can reduce the consumption power of LNB and improve the frequency characteristics at the same time Yes.The technical structure of this study is horizontal signal low noise amplifier (h-lna) (1),Vertical signal low noise amplifier (v-lna) (2),Oscillator (5),Mixer (3,4),Amplifier (12-15),Including diode block (db1-db4), in the multi-functional switching circuit of lnob, the transverse polarization signal and the vertical polarization signal in lnob are received at the same time,In the output of the diode block (db1-db4), the high-frequency signal is the integrated capacitor (C7, C8) and which are AC connected to the input of the next amplifier (14, 15),Direct current is composed of resistors (R1, R2) directly connected to the driving voltage end of amplifiers (14, 15).Therefore, according to the composition of this study, the complete consumption current of the existing diode block is taken as the resistance and the driving voltage of the amplifier. It is unnecessary to use special driving voltage for the amplifier, so the required electric force in LNB Reduce,At the same time, although the resistance value connected with the driving voltage end of the amplifier is small, the equivalent resistance is quite large due to the relationship between the bias resistance of the amplifier, which leads to the reduction of the loss of the communication signal,Therefore, the frequency characteristics are improved very well.