Abstract:
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.
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