GNSS兼容接收机天线高功率微波前门通道效应OA

[Background]Global Navigation Satellite System(GNSS)compatible receiver antennas—integrating multiple global navigation constellations—feature more complex front-door radio frequency(RF)channel architectures than single-constellation GPS antennas.High power microwave(HPM)effect research on GNSS compatible antennas with complex RF front-ends were rarely been reported.[Purpose]To investigate the GNSS compatible antenna HPM effects,radiation experiments on a type of GNSS-compatible receiver antenna were carried out,and a customized characterization approach was designed to analyze the damaged antennas and identify the specific failed components within the complex RF front-end.[Methods]The RF front-end structure of the antenna was analyzed,revealing a design with two separate RF channels(around 1.25 GHz and 1.6 GHz),each with a dedicated first-stage low-noise amplifier(LNA),followed by shared second and third-stage LNAs.The performance of these components was characterized employing a customized"hot measurement"setup,which used a vector network analyzer incorporating a test antenna and a DC blocker.[Results]The measurements pinpointed the failure to the first-stage LNA(Q6)of the RF channel corresponding to the HPM source frequency of 1.6 GHz.This specific component showed significant degradation or complete failure.In contrast,the first-stage LNA(Q4)of the other channel(～1.25 GHz)and the shared subsequent amplifier stages(Q2 and Q1)remained unaffected.The root cause was confirmed by replacing the damaged Q6 LNA,which successfully restored the antenna's full functionality.[Conclusions]This work demonstrates that in a multi-channel RF front-end,HPM effects can be highly localized,selectively damaging the first-stage amplifier of the channel that covers the HPM frequency while sparing other sections.The findings provide valuable insights into the HPM vulnerability of complex RF systems and offer a reference methodology for related effect analysis.