简洁构型与馈电的宽带双极化金属锥阵列天线北大核心CSCD

本文提出了一种宽带双极化金属锥阵列天线。该阵列天线以传统的旋转体天线结构为主体，通过在锥体底部开设四道正交的直通槽，以便在锥状单元内部形成可与地板间构成匹配谐振腔的开放式空腔结构。在阵列中，任意两个相邻的锥状单元之间可形成类似于Vivaldi天线的辐射缝隙结构。馈电采用同轴馈电方式，探针无弯折结构，金属锥体无弯折过孔。每个金属锥状单元独立，可极大简化加工、装配和维护过程。该天线具有两个正交极化，分别由左右和前后相邻单元构成。仿真结果表明，在频率范围为2～8GHz内，阵列大部分有源VSWR小于2，小部分端口有源VSWR小于2.5 (相对带宽为120%)。

A Low Loss Analog Predistorter Based on Schottky Diode

With the continuous development of the communication system, the fifth generation mobile communication system (5G) technology has higher requirements for radio frequency power amplifier(RF PA) in terms of power consumption, delay, bandwidth and so on. Although the traditional analog predistorter can improve the nonlinearity of the RF PA, it also has a certain insertion loss, resulting in decrease of the RF PA gain. In order to solve the loss problem, a quarter wavelength impedance converter is added at the wave nodes on both sides of the nonlinear device to match the impedance, which can suppress the intermodulation distortion and reduce the insertion loss. In the experiment, Doherty RF PA operating at 3.5 GHz is linearized by the proposed analog predistorter under a 100 MHz bandwidth 5G NR signal. The test results show that the analog predistorter improves the adjacent channel power ratio of power amplifier by more than 14 dB, and the insertion loss is less than 3 dB.