A Ku-band monolithic tuner-LNB for satellite applications [low noise block down-converter]

A 12-GHz monolithic tuner for digital video broadcasting via satellite (DVB-S) applications is presented. The tuner is able to convert the typical 36-MHz wide DVB-S channel, lying in the Ku-band (10.7-12.75 GHz), to a fixed 1.45 GHz intermediate frequency (IF). The IC consists of a down-converter block and a PLL that implements a programmable divider. When the LO frequency is set between 9.25 and 11.3 GHz, the phase noise is lower than -115 dBc/Hz at 1-MHz offset. For an 11.7-GHz input signal, the conversion gain is 34.5 dB, the single-sideband noise figure is as low as 7.5 dB, while the 1-dB output compression point is as high as +5 dBm. Over the entire RF band, the conversion gain variation is within 3 dB. This first Ku-band monolithic tuner represents an improvement compared to the traditional low noise block down-converter (LNB). Indeed, instead of down-converting a wide RF band, the tuner-LNB directly selects the desired DVB-S channel. Thus, a more flexible use of the antenna cable bandwidth is achieved.