Miniaturization of multi-arm multi-mode spiral antennas for GPS applications

全球定位系统（GPS）被广泛应用于测量、位置识别、导航、车辆速度计算、测绘和其他新型设备。它的使用似乎没有限制，并且经常实现或提出新的应用程序。其受欢迎的原因之一是GPS信号的可用性和易用性。然而，在大多数应用中，接收设备是移动的或处于无人值守的位置，需要低能耗和更长的电池寿命。该系统还必须是低成本的，不包括用于信号处理和干扰缓解的大型和复杂的电子设备。这些相互冲突的要求阻碍了有源器件的使用，并将一些信号处理转移到无源器件，特别是天线。天线阵列可以减少或克服干扰问题，但需要更大的空间来实现。设计下一代先进GPS系统的关键挑战之一是开发具有增强性能的小尺寸低成本天线阵列。

The Global Positioning System, GPS, is used in many applications for surveying, location identification, navigation, vehicular speed calculations, mapping and other novel devices. There seems to be no limit in its utilization, and new applications become implemented or proposed regularly. One of the reasons for its popularity is the availability of GPS signals for common use and ease of use. However, in most applications the receiving device is mobile or is in an unattended location that requires low energy consumption and longer battery life. The system must also be low cost, which excludes large and sophisticated electronics for signal processing, and interference mitigation. These conflicting requirements discourage the use of active devices and transfer some of the signal processing to passive components, especially antennas. Antenna arrays can reduce or overcome interference problems, but require larger space for implementation. One of the critical challenges in design of the next generation advanced GPS systems is in developing reduced-size low cost antenna arrays with enhanced performance.