A Q-band two-beam cryogenic receiver for the Tianma Radio Telescope（TMRT）has been developed,and it uses the independently-developed key microwave and millimeter-wave components operating from 35 to 50 GHz with a fra...A Q-band two-beam cryogenic receiver for the Tianma Radio Telescope（TMRT）has been developed,and it uses the independently-developed key microwave and millimeter-wave components operating from 35 to 50 GHz with a fractional bandwidth of 35%.The Q-band receiver consists of three parts：optics,cold unit assembly and warm unit assembly,and it can receive simultaneously the lefthanded and right-handed circularly polarized waves.The cold unit assembly of each beam is composed of a feed horn,a noise injection coupler,a differential phase shifter,an orthomode transducer and two low-noise amplifiers,and it works at a temperature range near 20 K to greatly improve the detection sensitivity of the receiving system.The warm unit assembly includes four radio-frequency amplifiers,four radio-frequency high-pass filters,four waveguide biased mixers,four 4–12 GHz intermediate-frequency amplifiers and one 31–38 GHz frequency synthesizer.The measured Q-band four-channel receiver noise temperatures are roughly 30–40 K.In addition,the single-dish spectral line and international very long baseline interferometry（VLBI）observations between the TMRT and East Asia VLBI Network at the Q-band have been successfully carried out,demonstrating the advantages of the TMRT equipped with the state-of-the-art Q-band receiver.展开更多
基金supported by the Special Fund for Astronomy from the Ministry of Finance, the National Natural Science Foundation of China (Nos. 11403080, 11590780 and 11590783)the Knowledge Innovation Program of the Chinese Academy of Sciences (No. KJCX1-YW-18)+1 种基金the Scientific Program of Shanghai Municipality (No. 08DZ1160100)the Youth Innovation Promotion Association of Chinese Academy of Sciences (No. 2017315)
文摘A Q-band two-beam cryogenic receiver for the Tianma Radio Telescope（TMRT）has been developed,and it uses the independently-developed key microwave and millimeter-wave components operating from 35 to 50 GHz with a fractional bandwidth of 35%.The Q-band receiver consists of three parts：optics,cold unit assembly and warm unit assembly,and it can receive simultaneously the lefthanded and right-handed circularly polarized waves.The cold unit assembly of each beam is composed of a feed horn,a noise injection coupler,a differential phase shifter,an orthomode transducer and two low-noise amplifiers,and it works at a temperature range near 20 K to greatly improve the detection sensitivity of the receiving system.The warm unit assembly includes four radio-frequency amplifiers,four radio-frequency high-pass filters,four waveguide biased mixers,four 4–12 GHz intermediate-frequency amplifiers and one 31–38 GHz frequency synthesizer.The measured Q-band four-channel receiver noise temperatures are roughly 30–40 K.In addition,the single-dish spectral line and international very long baseline interferometry（VLBI）observations between the TMRT and East Asia VLBI Network at the Q-band have been successfully carried out,demonstrating the advantages of the TMRT equipped with the state-of-the-art Q-band receiver.
