Pseudo-random Hopping RF Circuit Design

Pseudo-random hopping frequency technology is also called pseudo-random frequency shift keying technology, using the good "randomness" of pseudo random sequence to control the carrier frequency of "irregular" jump. The technology can not only ensure the excellent anti-jamming function, but also greatly improve the sensitivity of the system. Currently, the pseudo-random hopping frequency technology is widely used in civilian fields, such as automotive vehicle radars, wireless network communications. And the military aspects are more for the enemy target detection and so on.This topic includes two different frequencies of the vibration source, using pseudo-random sequence to control the high speed of RF switch to choose different carrier frequency. This method can be called2FSK modulation. The echo signal in Doppler information is mixed with the local oscillator signal by combining the pseudo-random hopping frequency technology with Doppler effect, and then the intermediate frequency signal can be filtered out. After processing such signals, both speed and distance information related to the target can be obtained.This paper first introduces the working principle of the pseudo-random hopping frequency radio detector and subsequently makes a mathematical deduction about the procedure of signal transmitting and receiving of the system based on Doppler effect. ADS2009RF microwave simulation software is used to simulate the whole system in order to ensure the theoretical correctness of the system at the top of the design. Then the technical indicators in each sub-module of the system can be put forward according to the overall simulation results. After further detailed design simulation, the actual circuit is at hand. Finally board figures can be drawn with Altium Designer software and the completion of welding operation and test work for the hardware can also be followed on after making Product PCB board.