关键词: 宽频段, 杂散, 平坦度, 谐波, 邻信道功率比

Abstract:

In military wide frequency range communication systems, the frequency-hopping filters are used to improve the anti-EMI features. The RF front-end of such systems will probably produce Abnormal Spur while transmitting RF signals. In high power mode, such RF front-end will result in deterioration of  RF power flatness。The harmonic energy will be raised by directional coupler. The harmonic suppression of the frequency-hopping filters will be weeken， and the ACPR of the RF signal will degrade because of frequency hopping filters. In this article, the interaction between the different modules in RF front end while connecting them together, and the characteristic change of the modules in high power mode are analysed to explain the reasons for the problems above. In the end, the corresponding solutions are presented, which have been applied in engineering practice.

Key words: wide frequency range;spur;flatness;harmonic;ACPR