Research On Microwave And Millimeter-Wave SIP Technologies Based On LTCC Process

SIP(System in Package)technology,which integrates several kinds of passive circuits,active circuits with different functions into a shell,is a kind of multi-functional system and sub-system module.With the demand of more function,miniaturization,lower weight and lower cost,SIP technology has became a stronger competitor in packaging area and the developing trend.At millimeter-wave band SIP module becomes smaller and smaller,which brings higher requirement on the substrate used in SIP.Due to the lower dielectric loss at high frequency,the good high-temperature stability and the familiar thermal expansion coefficient to MMIC chips,LTCC(Low Temperature Co-fired Ceramic)which is a multilayer fired process is appropriate to high and low frequency and analog/digital mix packaging.Meanwhile LTCC is a 3-D substrate,which could meet the requirement of high density wiring and compact passive circuits,can take the great advantages of large scale integrated circuits.In this dissertation the theoretical analysis and experimental research of microwave and millimeter-wave SIP technology based on LTCC,microwave monolithic integrated circuits(MMIC),millimeter-wave monolithic integrated circuits,LTCC passive circuits and packaging technology are represented,and a T/R module based on vector modulator(VM)was designed and researched.Specific research contents are shown as follows.1.The principle of the LNA and PA working at Ku band based on GaAs pHEMT is discussed on chapter 3.By deeply analyzing the power handling capacity of high power FET switch,a new novel topology which integrated the PA,LNA and switch together is proposed.A Ku band high power GaAs T/R chip and a Ka band T/R chip based on GaAs pHEMT process are developed successfully.The VM theory is analyzed in terms of the phase shift function,and a Ka band and a Ku band balanced Ga As VMs are designed.2.As to solve the drawback of GaN internally-matched PA which has the narrow band width and low gain,GaN HEMT process is researched.By utilizing microwave two port network theory,a high power amplifier is analyzed and optimized in terms of wide-band matching.A novel pre-matched technology is proposed,which deeply increased the bandwidth of "internally-matched amplifier" based on GaN process,and a Ku band GaN 30 W internally-matched amplifier is developed.3.Aiming to solve the problems of high system complexity,high cost and low phase shift accuracy of the proposal based on phase shifter,novel Ku band and Ka band T/R module,which utilize VM as the phase-shifted circuit are proposed.The phase shift function is verified in both modules which integrates T/R chip,VM and high power amplifier.4.Passive circuits such as RF transition and antenna are designed and fabricated based on LTCC technology.In the Ka band SIP a novel hermetic packaging design is proposed.Hermetic packaging based only on LTCC is proposed in this design,which can overcome the oscillation problems of traditional packaging based on metal.