Interest of the superconductivity at 30 GHz : application to the HTS preselect receive filters for satellite communications

Advances in Planar Filters

“…Significant efforts are invested in the design of HTS filters that operate at millimeter-wave frequencies (44)(45)(46) or that use various HTS materials (47,48). The proposed HTS filters differ in geometry, type of resonators used, operating frequency, bandwidth, and so on, but they all have similar characteristic features, such as extremely small passband insertion loss, high out-of-band rejection, and small size and weight.…”

A 23 GHz high-temperature superconducting microstrip filter for radio astronomy

“…According to ref. [14], the wider resonator has a relatively higher unloaded Q, because the current density of the resonator is more homogeneous. There are many complex structures of planar resonator [1,2,17] .…”

“…With the growth of the frequency, the microwave surface resistance of HTS materials increases rapidly. There are some achievements of producing HTS filters in X-band, K-band, even Ka-band [12][13][14] , revealing the potential ability of planar HTS filters with high performance. Urumqi Observatory, Chinese Academy of Sciences (CAS), recently required a low loss filter for their K-band (1.3 cm wavelength) low noise cryo-receiver of 25 m telescope, which was a challenge for us to study high performance planar HTS filters in such a high frequency, as it is generally acknowledged that the higher of the frequency the harder of the techniques.…”

Study of optically controlled high temperature superconducting microwave variable attenuator

“…Attenuator, as the important device in a HTS system [3], exerts great functions in leveling off signal, improving receiving and transmitting quality, and avoiding the influences of climate and other environments [4]. An attenuator, which possesses superexcellent capabilities including low insertion loss, high tuning precision, and working in liquid nitrogen temperature(the base of attenuator integrated into a HTS system), is greatly important to the development and application of HTS system [5].…”

“…Wavelength converters can be useful in the wavelength allocation, allowing the use of different wavelengths on the links along the route [1,2]. The main advantage of all-optical processes is that they do not require conversion to the electrical domain-this is especially true as bit rates increase to 10 Gb/s and beyond [3].…”