RF Circuit Design And Implementation Of Blind Signal Measurement Receiver

The radiated emission of extra-large high speed mobile electrical equipment has no efficient methods to measure. The development of blind signal processing offers an opportunity and theoretical support to measure the radiated emission of thus equipment outside the anechoic chamber. Based on the receiver theory, radio frequency (RF) circuit technology and electromagnetic compatibility technology, this paper designed and completed a dual-channel RF circuit of blind signal measurement receiver.The receiver’s structure is studied and analyzed first. The RF circuit structure of the blind signal measurement receiver in this paper is designed by combining zero intermediate frequency (IF) architecture and software radio technology. The mirror interference in the receiver is analyzed especially. A method using hardware circuit and software signal processing together is proposed to solve this problem. This paper also analyzes the relevant problems of impedance matching in RF circuit.The main function modules are designed and completed to integrate the RF circuit in this paper:(1) Filter:based on the filter theory, performance simulation and lab measurement, a low-pass filter (up to10MHz) and a band-pass filter (100MHz-1GHz) are designed;(2) Low Noise Amplifier (LNA):MGA62563chip is chosen to use in the LNA, and the design of LNA hardware circuit is completed by ADS simulation;(3) Phase Locked Loop (PLL):ADF4351chip is used in the circuit and the control of PLL is completed by a microcontroller;(4) Attenuator:a variable digital control attenuator is designed using HMC470LP3chip;(5) Frequency Mixer:ADL5387chip is used to complete the down-converting of the input RF signal by complex frequency mixer.The EMC performance of the RF circuit built in this paper is designed and developed from three aspects:device selection, PCB design and system design. According to the requirements of EMC performance of Information Technology Equipment in China, measurements are taken to test the RF circuit. The test results shows the RF circuit designed in this paper meets all the requirements and works very well.