Research On W-band Planar Integrated Phased Array Front-end

Research into W-band active phased array radar has become a major focus in millimeter wave due to its high resolution,flexible beam scanning,and capacity to monitor multiple objectives,etc.Currently,there are relatively few research and reports on W-band active phased array radars in China.Hence,this thesis is founded on W-band single channel T/R bare chips,4T/4R bare chips,coupled with bonding wire(WB)interconnection technology and multi-layer printed circuit board(PCB)technology to execute COB(Chip On Board)chip packaging design and planar integrated phased array receiver transceiver front-end research.The main research work is as follows:Firstly,the WB technology was applied to the transition structure of W-band grounded coplanar waveguide(CPWG)to substrate integrated waveguide(SIW).Subsequently,a Chip-WB-CPWG-SIW transition structure was designed,with insertion loss of less than 1.4 d B and return loss of more than 15 d B in the frequency range of 90-98 GHz.By integrating the SIW slot antenna with the transition structure,a planar integrated single channel transmitter front-end has been developed.The measured results show that the equivalent omnidirectional radiation power(EIRP)of the single channel transmitter front-end can reach up to 27.3 d Bm in the 92-94 GHz frequency band range.Secondly,based on multi-layer PCB technology,the Ku band interlayer transition structure simulation design,the one-eighth power division network simulation design,and the DC-50 MHz chain power combination network design were carried out.Then,combining these design structures with the W-band SIW dual polarization slot antenna array and the W-band Chip-WB-CPWG-SIW transition structure,a planar integrated phased array transceiver front-end were developed.The test results show that the frequency conversion gain of the phased array receiver can reach up to 24 d B for a single channel in the range of 92-94 GHz,and the maximum frequency conversion gain can reach up to 28 d B when the four channels of a single polarization are fully open.At the same time,the simulation results are in good agreement with the measured directional pattern results,but due to partial damage or large phase shifting error of the chip phase shifter,only a 15 ° scanning range was measured.The Phased array transmitters have an EIRP of up to 34.8 d Bm in the 91.5-93.5 GHz,while achieving a beam scanning range of± 50°,and a gain reduction less than 2 d B when the scanning angle reaches± 50°。Finally,in view of the electromagnetic coupling and crosstalk problems that are prone to occur in multi-channel T/R chips due to their close channel distances,a COB packaging design based on gold wire bonding technology was conducted.The RF simulation results demonstrate that,within the range of 78-98 GHz,the return loss is superior to 12 d B,the insertion loss is less than 1.5d B,the amplitude difference is below0.8d B,the phase difference is less than 4°,and the isolation surpasses 25 d B.At the same time,CPWG fanout and CPWG rectangular waveguide(RWG)transition models were introduced,and the overall packaging module and back to back structure of 4T/4R chips were designed and fabricated.The test results verify the feasibility and excellent performance of the chip packaging design,and the related structures can be used in multichannel chip packaging and phased array systems.