With GPS/Global Navigation Satellite System (GNSS) receivers exposed to greater levels of Radio Frequency Interference (RFI), a potential problem is the saturation of the receiver front end (FE). This problem is further complicated in typical multifrequency receivers by the interfrequency saturation effect. Specifically, any inband RFI targeted to induce FE saturation at only one specific GPS/GNSS frequency, if not properly handled, would potentially impact the reception of the other frequencies. This paper presents the design of an antenna module to detect, identify, and isolate potential RFI to prevent FE saturation including that due to the interfrequency effect. Analysis showed that any specific antenna module configuration with fixed internal components must sacrifice noise figure (NF) performance to increase robustness to RFI saturation, and vice versa. To provide a compact solution to this dilemma and the interfrequency saturation issue, two dynamically configurable antenna modules based on the concept of network topology were proposed for typical dual-frequency GPS/GNSS receivers. Such a solution can adapt to different RFI conditions by operating in corresponding modes resulting in a better NF versus robustness tradeoff. The proposed antenna-module design was validated by experiments with live GPS signals under controlled RFI conditions.

中文翻译：

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抗 RFI 饱和的可配置 GPS/GNSS 天线模块

随着 GPS/全球导航卫星系统 (GNSS) 接收器暴露于更高水平的射频干扰 (RFI)，潜在问题是接收器前端 (FE) 的饱和。由于频率间饱和效应，这个问题在典型的多频接收器中变得更加复杂。具体而言，任何旨在仅在一个特定 GPS/GNSS 频率上引起 FE 饱和的带内 RFI，如果处理不当，都可能影响其他频率的接收。本文介绍了一种天线模块的设计，用于检测、识别和隔离潜在的 RFI，以防止 FE 饱和，包括由于频率间效应引起的饱和。分析表明，任何具有固定内部组件的特定天线模块配置都必须牺牲噪声系数 (NF) 性能以提高对 RFI 饱和的鲁棒性，反之亦然。为了为这一困境和频间饱和问题提供紧凑的解决方案，针对典型的双频 GPS/GNSS 接收器提出了两种基于网络拓扑概念的动态可配置天线模块。这种解决方案可以通过在相应的模式下运行来适应不同的 RFI 条件，从而实现更好的 NF 与稳健性权衡。通过在受控 RFI 条件下对实时 GPS 信号进行实验验证了所提议的天线模块设计。这种解决方案可以通过在相应的模式下运行来适应不同的 RFI 条件，从而实现更好的 NF 与稳健性权衡。通过在受控 RFI 条件下对实时 GPS 信号进行实验验证了所提议的天线模块设计。这种解决方案可以通过在相应的模式下运行来适应不同的 RFI 条件，从而实现更好的 NF 与稳健性权衡。通过在受控 RFI 条件下对实时 GPS 信号进行实验验证了所提议的天线模块设计。