| Due to the multi-beam forming and fast beam scanning capabilities of phased array technology,active phased array systems are widely used in radar and communication fields.The T/R chip plays a significant role in the active phased array system.It's cost,size,and performance will play a decisive role in the entire radar system,so it has become one of the research hotspots.In this paper,using the advantages of ?-?semiconductors in frequency and performance,for the Ka band applied to satellite communications,based on the Win PP15 process,a multi-function chip is researched and designed,which integrates low noise Amplifiers,power amplifiers and switch;for C?X and Ku bands,based on the domestic Sanan Optoelectronics SANAN-IC P15LN process,a broadband low-noise amplifier chip has been researched and designed,which has made a useful exploration for the application of RF front-end chips in broadband.The main research work is as follows:1.Aiming at the gain roll-off of the broadband low-noise amplifier in the 6-18 GHz,the RLC parallel negative feedback network used to present a positive slope gain in the frequency band to improve the flatness of the entire circuit.At the same time,source negative feedback and parallel peaking technology used to reduce the influence of parasitic parameters,achieve the purpose of expanding bandwidth and improving matching,and have a certain output power under the premise of meeting low noise.Finally,the results of simulation show that the low noise amplifier has good performance in noise figure which less than 1.4,the flatness of gain in-band is ±0.6dB,1dB compressed output power of 15 dBm,the return loss is better than 10 dB in band.2.Aiming at the influence of switch insertion loss and isolation on the multi-function chip,a new switch structure proposed.Under the precondition of ensuring signal control and isolation,the insertion loss of the transmitting branch reduced.The input 1dB compression point power of the switch is increased,and the influence of the nonlinearity of the switch on the linearity of the multi-function chip avoided.The final results of EM simulation show that for the receiving branch the insertion loss is less than 0.9dB,on the other hand,for transmitting branch the insertion loss of the is less than 0.4dB,and the isolation is greater than 18 dB.3.Aiming at the high and low temperature fluctuations of amplifier gain,a temperature compensation attenuator is designed to compensate amplifier gain fluctuations,achieving an attenuation range of 9dB at high and low temperature,after the tape-out test,accumulate design experience.Using this principle,in the design of the receiving branch of the T/R multi-function chip,integrated the temperature-compensated attenuator and controls its working state through the external power supply voltage.Finally achieves a 5dB attenuation range in the 33-36 GHz frequency band.4.Regarding the output power of the amplifier,the influence of the synthesis network,matching method,and optimal impedance point on the output power and efficiency analyzed.The result of simulation show that the T/R chip has a good performance at output power which greater than 28 dBm and efficiency which greater than 20%.Comprehensively considering the interaction between the unit modules,port impedance,layout and other factors to complete the integrated design of the T/R multi-function chip.Finally,compare the difference between the simulation and test results and find the reasons for the difference. |
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