GNSS使用PIFA天线实现宽带线性极化辐射和宽带圆极化

Normally, in order to better receive GNSS signals, the navigation and positioning antenna needs to be designed as a circularly polarized antenna.通常，为了更好地接收GNSS信号，导航和定位天线需要设计为圆极化天线。 To realize the circular polarization radiation characteristics of the antenna, there are many strict requirements in terms of radiating element, antenna base material, and feeding method.为了实现天线的圆极化辐射特性，在辐射元件，天线基材和馈电方法方面有许多严格的要求。 This is also the reason why it is difficult to make the size of the navigation and positioning antenna small.这也是为什么难以减小导航和定位天线的尺寸的原因。

实现天线圆极化的常用方法：

单馈点微带天线（如普通汽车导航陶瓷天线）

双馈点微带天线（例如亚米级手持导航天线）

四馈微带天线（例如高精度测绘天线）

单臂，双臂或四臂螺旋天线（例如无人机定位天线）

转换后的振荡器（如北斗短信指令接收机的S波段接收天线）

螺旋天线（宽带导航定位天线）

...

上述天线具有共同点，即结构的对称性，对称性的要求直接决定了天线只能是正方形，圆形，圆柱形，圆锥形等。这一特点也极大地限制了天线的应用。在终端设备中，导致大型终端设备或有限的ID设计。

一种宽带PIFA圆极化天线的实现方法：

Here is an article published by Beijing University of Posts and Telecommunications Xing Wang and other authors at the Asia Pacific Microwave Forum.这是北京邮电大学的王兴和其他作者在亚太微波论坛上发表的文章。 They proposed a PIFA antenna structure that can achieve broadband circular polarization, which provides a new way for the formulation of antenna solutions in engineering practice.他们提出了一种可以实现宽带圆极化的PIFA天线结构，为在工程实践中制定天线解决方案提供了新途径。 Ideas.想法。 The antenna is a flat structure, the radiating element is coplanar with the metal ground.天线为扁平结构，辐射元件与金属地面共面。 The design of the inverted F antenna at the edge of the metal floor and the cross structure at the edge of the floor have achieved a wide frequency band circularly polarized radiation covering 1.1GHz to 1.7GHz.金属地板边缘的倒F天线的设计和地板边缘的十字结构的设计实现了覆盖XNUMXGHz至XNUMXGHz的宽频带圆极化辐射。

（1）天线结构设计图

（2）天线宽带回波损耗

（3）天线宽带轴向比

（4）宽带天线增益

天线设计的启示：

The principle of this antenna is to use the PIFA antenna to achieve broadband linear polarization radiation, and then change the distribution of the radiation current through the cross groove on the edge of the metal ground.该天线的原理是使用PIFA天线实现宽带线性极化辐射，然后改变通过金属地面边缘上的沟槽的辐射电流的分布。 After precise adjustment of each size, the broadband circular polarization is finally realized.在精确调整每个尺寸之后，最终实现了宽带圆偏振。 In the same way, in the future plate-level antenna design, in addition to the traditional use of the radiating unit itself to achieve circular polarization, circular polarization can also be achieved through radiation superposition of other auxiliary structures and the main radiator.同样，在未来的板级天线设计中，除了传统使用辐射单元本身实现圆极化外，还可以通过其他辅助结构和主辐射体的辐射叠加来实现圆极化。