Читать книгу Handbook of Microwave Component Measurements - Joel P. Dunsmore - Страница 104

The final RF components in a VNA block diagram are the test and reference receivers. Dynamic range is a key specification of a VNA and is sometimes referred to as the difference between the maximum signal level that the receiver can accept while still operating and the noise floor of the receiver. In most cases, the maximum damage level is significantly above the maximum operating level of the receiver, which is usually limited by the input compression level of the receiver. The maximum operating level is set by the structure of the components, but for most modern VNAs, it is around the −5 dBm at the receiver mixer input, or about +10 dBm at the test port, after considering the coupling factor of the test port coupler. The noise floor of the receiver is set primarily by the type of mixing down‐converter used, of which the two principal types are sampling down‐converters (or samplers) and mixers.