A platelet W-band feed horn-OMT assembly

Future Cosmic Microwave Background polarisation experiments will require large detector arrays to achieve the required sensitivity for precise measurements. New cost- and time-effective techniques are required for mass production of high performance passive components. We present electromagnetic test results on an assembly of feed horn and OMT prototypes, operating in the W-band and fabricated by means of 'platelet' technique. The good level of isolation and return loss (respectively >45 dB, >30 dB on 20% bandwidth) for both polarizations are in agreement with numerical simulations, indicating good matching between components. Radiation patterns are also in agreement with simulations, with cross-polarization level < -30 dB on a 20% bandwidth. These results confirm the good design, manufacturing and assembling of the prototypes