Non-reciprocal amplitude limiter

Abstract

The invention provides a non-reciprocal amplitude limiter which comprises a receiving and transmitting shared path, the receiving and transmitting shared path comprises a first input / output end, a directional coupler, an amplitude limiting circuit and a second input / output end which are connected in sequence, and a detection circuit, an amplifier and a comparator are connected between the directional coupler and the amplitude limiting circuit. The directional coupler couples out part of energy from the receiving and transmitting common path and sends the energy to the detection circuit, direct current detection voltage output by the detection circuit is amplified by the amplifier and then input to the comparator to be compared with a reference level of the comparator, the comparator outputs high / low level to the amplitude limiting circuit to provide direct current bias, and the starting limit level of the amplitude limiting circuit is changed. The starting limit level of the amplitude limiter is higher than the transmitting power, so that a transmitting signal smoothly passes through; when the signal is received, the limit starting level of the amplitude limiter is low, so that the amplitude of the received signal is limited in a required range. According to the invention, the nonreciprocity of the amplitude limiter is realized.

Description

technical field [0001] The invention relates to the technical field of radio frequency microwave circuits, in particular to a non-reciprocal limiter. Background technique [0002] A limiter is a common radio frequency device used to limit the amplitude of the output signal within a certain range. Usually the limiter is connected before the low-noise amplifier of the T / R component to protect the low-noise amplifier and the receiver from being damaged by high-power signals, but it cannot effectively protect the transmitter and the transceiver switch. [0003] Existing limiters are generally not directional. For a single-stage limiter, the limiting performance when the signal is input in both directions is basically the same; for a multi-stage limiter, the limiting structure of the previous stage is usually optimized to improve the withstand power, and generally requires one-way input and one-way output. Therefore, when using the existing limiter to protect the transmitter an...

AI Technical Summary

Problems solved by technology

Therefore, when using the existing limiter to protect the transmitter and the transceiver switch, the transmitted signal will be limited at the same time

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