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MRI at Ultrahigh Field (UHF) is complicated by interferences that occur in the transmit field (B 1 +) as a result of the relatively short wavelength of the RF transmit field compared to the dimensions of the imaging region [1], [2]. These interferences produce areas of spatially dependent image contrasts. In order to mitigate the inhomogeneous transmit field, multichannel transmit array systems have been developed. In such a system it is possible to independently control the amplitude and/or phase of each individual element, as well as to apply different RF pulses to each channel.

A novel design of small frequency reconfigurable monopole antenna has been proposed. The antenna was entirely made of copper and reconfigurability was achieved by changing positions of ground connections. Three antenna configurations that resonate at 2.2, 2.7 and 3.4GHz were presented. The prototype measurements show good agreement with the simulation results.

Microwave radiometers are widely used for remote sensing and radio astronomical observations. Their absolute accuracy depends on the performance of the blackbody targets which are used for the radiometric calibration. In this paper we summarize the performance aspects of such calibration targets and present different designs for upcoming ESA missions.