COTS Satellite Receiving Terminal's Antenna Measurement Practice and Analysis

Antennas classified as commercial-off-the-shelf (COTS) typically consist of a highly integrated system combining a reflector-type antenna with a multi-functional front-end referred to as a low-noise block (LNB). These integrated terminals receive signals at a radio frequency (RF) and output them at an intermediate frequency (IF). The antenna performance of such terminals is critical for ensuring reliable communication in satellite broadcast reception and other services. However, the performance characterization of these terminals is complicated by their integrated nature, meaning that a two-port measurement is not possible without destructive modification. This paper presents a procedure for characterizing the antenna performance of COTS terminals. The measurement setup includes a near-field scanner and a vector network analyzer (VNA) to capture the antenna's radiation pattern and polarization purity. The challenges of measuring the antenna performance of integrated systems is discussed, providing insight into the impact of design choices on the performance.