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## L-band Wideband Frequency Converters for Radio Astronomy Receiving Systems

Transactions of IAA RAS, issue 48, 75–80 (2019)

Keywords: frequency converter, mixer, superheterodyne, VLBI.

### Abstract

The paper presents the results of the development of a broadband frequency converter microassembly over L-band frequencies for blocks of frequency converters of radio astronomic receiving systems. The microassembly of the converter is realized in two versions: without a heterodyne and with a built-in heterodyne. The paper considers only one version, namely, without a built-in heterodyne. The converter is built in a superheterodyne scheme with a single “down” frequency conversion without spectrum inversion. It contains a preselector with a modulator, a mixer and an intermediate frequency channel. Bandwidth at 3 dB level is 340 MHz. The uneven amplitude-frequency response is no more than 1 dB. The nominal frequency of the heterodyne is 1.26 GHz with a signal power of 0.8 mW. The transmission coefficient of the converter is 35 dB at «zero» attenuation of the amplitude modulator, which has two values 0/10 dB. Amplitude modulation of the gain of the converter is used in the radiometric mode of the radio telescope. The attenuation of the combination components and noise of the mirror channel is more than 60 dB. The upper limit of the amplitude characteristic linearity by (of/on/at) 1 dB compression level is 10 mW. The equivalent noise temperature of the converter is not more than 90 K , which corresponds to the contribution to the system noise temperature of the order of 0.2 %. Converters are designed to be installed on the radio telescope RT-32. The principles of the construction and functioning of the main nodes of the conversion path, as well as its main parameters are given.

### Citation

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A. V. Krokhalev. L-band Wideband Frequency Converters for Radio Astronomy Receiving Systems // Transactions of IAA RAS. — 2019. — Issue 48. — P. 75–80. @article{krokhalev2019, abstract = {The paper presents the results of the development of a broadband frequency converter microassembly over L-band frequencies for blocks of frequency converters of radio astronomic receiving systems. The microassembly of the converter is realized in two versions: without a heterodyne and with a built-in heterodyne. The paper considers only one version, namely, without a built-in heterodyne. The converter is built in a superheterodyne scheme with a single “down” frequency conversion without spectrum inversion. It contains a preselector with a modulator, a mixer and an intermediate frequency channel. Bandwidth at 3 dB level is 340 MHz. The uneven amplitude-frequency response is no more than 1 dB. The nominal frequency of the heterodyne is 1.26 GHz with a signal power of 0.8 mW. The transmission coefficient of the converter is 35 dB at «zero» attenuation of the amplitude modulator, which has two values 0/10 dB. Amplitude modulation of the gain of the converter is used in the radiometric mode of the radio telescope. The attenuation of the combination components and noise of the mirror channel is more than 60 dB. The upper limit of the amplitude characteristic linearity by (of/on/at) 1 dB compression level is 10 mW. The equivalent noise temperature of the converter is not more than 90 K , which corresponds to the contribution to the system noise temperature of the order of 0.2 %. Converters are designed to be installed on the radio telescope RT-32. The principles of the construction and functioning of the main nodes of the conversion path, as well as its main parameters are given.}, author = {A.~V. Krokhalev}, doi = {10.32876/ApplAstron.48.75-80}, issue = {48}, journal = {Transactions of IAA RAS}, keyword = {frequency converter, mixer, superheterodyne, VLBI}, pages = {75--80}, title = {L-band Wideband Frequency Converters for Radio Astronomy Receiving Systems}, url = {http://iaaras.ru/en/library/paper/1956/}, year = {2019} } TY - JOUR TI - L-band Wideband Frequency Converters for Radio Astronomy Receiving Systems AU - Krokhalev, A. V. PY - 2019 T2 - Transactions of IAA RAS IS - 48 SP - 75 AB - The paper presents the results of the development of a broadband frequency converter microassembly over L-band frequencies for blocks of frequency converters of radio astronomic receiving systems. The microassembly of the converter is realized in two versions: without a heterodyne and with a built-in heterodyne. The paper considers only one version, namely, without a built-in heterodyne. The converter is built in a superheterodyne scheme with a single “down” frequency conversion without spectrum inversion. It contains a preselector with a modulator, a mixer and an intermediate frequency channel. Bandwidth at 3 dB level is 340 MHz. The uneven amplitude-frequency response is no more than 1 dB. The nominal frequency of the heterodyne is 1.26 GHz with a signal power of 0.8 mW. The transmission coefficient of the converter is 35 dB at «zero» attenuation of the amplitude modulator, which has two values 0/10 dB. Amplitude modulation of the gain of the converter is used in the radiometric mode of the radio telescope. The attenuation of the combination components and noise of the mirror channel is more than 60 dB. The upper limit of the amplitude characteristic linearity by (of/on/at) 1 dB compression level is 10 mW. The equivalent noise temperature of the converter is not more than 90 K , which corresponds to the contribution to the system noise temperature of the order of 0.2 %. Converters are designed to be installed on the radio telescope RT-32. The principles of the construction and functioning of the main nodes of the conversion path, as well as its main parameters are given. DO - 10.32876/ApplAstron.48.75-80 UR - http://iaaras.ru/en/library/paper/1956/ ER -