Research On HTS Receiver Front-end For New Generation Mobile Communication

With the rapid development of new generation mobile communication technology,spectrum resources below 6GHz are scarce and severely disturb.The industry begin to pay its attention to the subsequent evolution and rich spectrum resources of 5G millimeter-wave.Therefore,it is significant to study the receiver front-end with high working frequency and high performance.In this article,the high temperature superconducting(HTS)thin-film material is used to study the new generation of HTS receiver front-end for mobile communication.And the receiver front-end is composed of cascade HTS filter and low temperature noise amplifier,and the working frequency band is located in two discontinuous frequency bands of K band.For the passive part,we firstly put on analysis and comparison in several resonators suitable for K band HTS filter,and adopted an improved SIR resonator.Then,Sonnet electromagnetic simulation software and single port group delay method are used to simulate and design two kinds of K-band ultra-narrowband HTS filters separately,with relative bandwidths of 0.8%and 2%.On this basis,a defect ground structure(DGS)is introduced to a HTS filter with a relative bandwidth of 2%,and the effect of the DGS on the narrow-band HTS filter is simulated and analyzed.Then Discussed and compared the design methods of multi-pass band filtering,and theoretically analyzed the T-node matching network.Finally,a 5G millimeter-wave dual-passband HTS filter is designed by using the parallel method of two bandpass filters.The test results show that the maximum depth of out-of-band suppression is about 65dB,and the stopband depth between two passbands is about 35dB.For the active part,the selection of the MMIC low noise amplifier chip was completed according to the design index requirements of this project,and the stability,input-output matching and gain of the MMIC chip were analyzed by ADS microwave circuit design software.After that,the S-parameter and noise coefficient of the low noise amplifier were measured at room temperature and low temperature respectively.At 70K low temperature,the measured gain was 20±0.5 dB and the return loss was greater than 9 dB in the working frequency band 24?26 GHz,and the noise coefficient was within 1.2 dB at low temperature.Finally,cascaded the millimeter-wave double-passband HTS filter and low noise amplifier,the HTS receiver front-end for the new generation of mobile communication can be obtained.In a vacuum environment and 70K low temperature,the indicators of the HTS receiver front-end are as follows:the bandwidth of the two passbands is 24.21?24.41GHz and 24.67?25.2GHz respectively,the noise coefficient in the two passbands is less than 3dB,the gain is greater than 16dB,the isolation degree and the out-of-band suppression are better than 35dB,which meet the design objective.