Beidou RDSS Transceiver Module Design And Fabrication Of LTCC

The Beidou satellite navigation system is an important space infrastructure that China operates independently.By the development of the Beidou industry standard,satellite navigation and the national economy and individual industries are deeply integrated.Currently,our country is building No.three system of Beidou actively,which will play an important role in national security and public life.This project has been designed and manufactured by a transceiver module for Beidou Positioning and navigation system.The working band of the module is L band(1615.68MHz)and S band(2491.75MHz).The S band achieves-110dBm antenna signal reception,and its receiving channel gain reaches 60dB and other RF indicators.And L band achieves the minimum power value of 10dBm carrier signal,and its carrier suppression reaches-35dBc and other RF targets.The module adopts the LTCC(low temperature co-firing ceramic)technology and 3d stereo SIP packaging structure to realize module miniaturization.The main contents of this paper are as follows:(1)Design and production of microwave passive components.In order to improve the outside band suppression in the channel,the RDSS module is built into the S/L band pass filter inside the substrate,and the input port in Bobbi is less than 1.5.In the 825MHz?960MHz and 3.5GHz?6GHz band,the external suppression index of less than-35dBc is realized.(2)Design and manufacture of microwave passive baron.According to the requirements of RF transceiver chips,a S band 200 ? is designed to achieve impedance transformation,and the input standing wave is less than 1.5,the output amplitude is less than 0.3,and the output phase balance is less than 5°.(3)The selection and layout of active circuit devices.According to the RDSS Beidou transceiver chip to develop the corresponding peripheral circuit,and then select the corresponding low noise release,switch,FBAR filter and so on according to the index.How to distribute hundreds of devices in the 16mm*18mm space is the key technology to realize the miniaturization of the module.(4)SIP encapsulation to solve electromagnetic compatibility problems.Based on the transceiver module of LTCC technology,the layer and layer interval between the ceramic substrate and the layer are 0.1mm,and the internal transmission lines cross each other.There will be serious coupling and crosstalk.The electromagnetic compatibility problem is solved by adding metal isolating wall and modulus separation technology.After the design and production of the RDSS module,the finished product is tested.By comparing the radio frequency indexes such as signal receiving power,transmitting power,noise coefficient,phase noise and so on,it is basically consistent with the design requirements,and the miniaturization of the Beidou transceiver is realized.