高隔离度和ns级响应时间的主动式射频前端限幅设计方法

用于防止射频前端受到物理损伤的限幅器，其限幅输出电平难以得到有效抑制，并且容易导致敏感的低噪声放大器进入深度饱和状态，影响接收通道的正常工作。因此，提出一种具有高隔离度和ns级响应时间的主动式射频前端限幅模块设计关键技术。经实验验证，所设计的模块通过集成检波器、高速比较器和多级PIN二极管，能够较大程度的降低限幅模块的饱和阻抗，提高强射频信号注入时的隔离度，从而降低泄露到后级敏感模块的功率等级，防止接收机进入深度饱和状态。

A design method for high isolation and nanosecond response RF front-end active limiter module

The output voltage level of the limiter for protecting the RF front-end from physical damage is difficult to reduce, and often leads the low noise amplifier to enter into deep saturation, disturbing the normal function of the receiving channel. To solve this, we introduce a high isolation and nanosecond response RF front-end active limiter module with key technology of parameter design and measurement. The proposed limiter module is made up of an integrated detector, high-speed comparator and multi-stage PIN diode. The saturation impedance of the limiter module is degraded on a large scale and the isolation is increased remarkably. In this way, the leakage power level to the later sensitive module is reduced and the receiver is prevented from entering deep saturation.