Microwave multi-tool
A resonator element that can simultaneously act as both a filter and antenna has been developed as a step towards creating PROMFAs - the microwave circuit equivalent of an FPGA.
Flexibly functional
A programmable microwave function array (PROMFA) is a network of microwave hardware that can be reconfigured to assume different circuit functions. "It has the potential to revolutionise the microwave industry; reducing the development time and weight of systems while increasing their flexibility" explained Dr James Kelly, one of the authors of the paper reporting the advance, published in this issue of Electronics Letters.
The vast majority of microwave hardware functionality is fixed at the time of manufacture, whereas a PROMFA could be reconfigured in operation; enabling the system to respond to changes in operational requirements. Such an array would consist of 'building block' elements analogous to the logic blocks in an FPGA, with each element able to assume different circuit functions, on demand, giving a lot of functionality in a compact volume.
Not only would this allow valuable volume and weight savings, it is possible that such PROMFAs could be made capable of altering their internal wiring to bypass faulty components, extending their operating lifetime. "This would be particularly valuable in applications where the hardware is difficult or impossible to access for maintenance and upgrades, such as space satellites," said Kelly. "The technology will also reduce the cost and time associated with the hardware development cycle, because components will become off-the-shelf items that no longer require customisation."
The PROMFA concept has been around since at least 1990, but its development has been hard to track, as Kelly explained: "The majority of PROMFA work has been confined to the military domain. We assume only a small proportion of the results achieved have been openly published. However, it is likely that cost and complexity have been a major drawback. It is also challenging to devise a hardware block with a simple structure that can be reconfigured to assume a wide range of different circuit functions." Reconfigurability has often meant a trade-off in performance, so that the reconfigurable device did not match the function specific performance of its single function equivalent.
- TAMS SEMICONDUCTOR LIMITED