Solutions

The 3dB to 6dB improvement in receive sensitivity afforded by a typical HTS RF Front End over a non-HTS solution is achieved through two independent mechanisms. Firstly, the cryocooling of the RF receive filter and LNA greatly reduces the Noise Figure of the base station, giving over 2dB performance gain over a base station fitted with the best conventional LNA on the market today. Secondly, the excellent selectivity of the HTS RF filter blocks out-of-band noise entering the receive chain and desensitising the base station. Whilst the extent of the resulting performance improvement is difficult to quantify and will vary by base station, it is expected to be significantly more than 2dB and published research indicates that it may even exceed 5dB.

This performance improvement is stated compared to the “typical” specifications quoted by equipment vendors. The performance of the HTS solution does not change with changes in ambient temperature (due to the circuits being contained in a temperature-stable housing maintained to ±0.1°C) and thus there is no variation in performance when the unit is installed in an outdoor hot or cold climate – unlike the conventional unit, where its noise figure increases when it warms up. This factor also gives very high HTS product reliability.

The HTS transmit RF Filter can also free up non-revenue generating spectrum that has been allocated as inter-system guard bands. It can also provide performance improvement to systems operating in adjacent spectrum. The extremely high selectivity of the HTS RF Filter removes any significant out-of-band emissions, thereby avoiding transmitting interference to adjacent systems.

It has been demonstrated that the HTS LNA technology can generate significant financial returns for Operators in terms of both cost savings and revenue enhancement.