Precision RF channel development for high performance HF systems

An HF RF channel for precision amplitude and phase measurement with wide dynamic range is required in a wide variety of HF systems applications, including cross spectral and super-resolving DF systems. The techniques that are used to improve the performance have application to both broadband and narrowband system designs. In all cases extreme linearity is required to operate without input preselective filters and still ensure that spurs, images and noise are minimised. Certain analogue components such as amplifiers, mixers, and filters, are critical, but their distributions, terminations and thermal design are also important when used to produce performance in areas beyond that currently available. Novel techniques are required in all these areas. In addition the number of components must be minimised prior to digitisation to increase the dynamic range. The architecture and the component requirements are discussed in detail with some practical measurements that quantify the limiting performance and the matching that can be achieved