The first test piece that Optisys put together was a K-band monopulse comparator with SMA connectors. We wanted a demonstration piece with test data that could be put into customer hands to show how RF and mechanical designs could be realized in additive manufacturing. We decided to on a K-band comparator for the following reasons:
1. K-band of is interest in commercial and military satellite communications.
2. Higher frequencies, like K-band, require tracking and monopulse is attractive because it doesn’t deliberately steer either the receive or transmit beam off target.
3. Coax connectors were used in place of more typical waveguide flanges for ease of testing. Providing test results is an important part of demonstrating the capabilities of the technology.
4. In addition to answering requirements for tracking solutions, a monopulse comparison is also useful for demonstrating complexity such as:
a. Integration of multiple components into a single printed piece assembly
b. Waveguide math
c. Gain and phase requirements
Our comparator weighs 2.6 oz (73 g) and has maximum dimensions of 2.5” x 2.1” x 2.5” (64 x 54 x 64 mm). Without system requirements, our design is best compared against predicted behavior from simulations and on those grounds it does very well. Simulated performance and measured test results for power slips, phase errors, return loss and insertion loss can be found on the Optisys website in the downloads section.