The present invention provides a radio frequency (RF) antenna device (140) for providing magnetic resonance (MR) information from an examination space (116) of a MR imaging system (110), comprising at least one RF coil (142) with at least one connection port (144) for receiving an analog MR information signal, and at least one analog to digital converter (ADC) (150), which is connected to the at least one connection port (144) and which converts the analog MR information signal into a digital MR information signal, whereby the at least one ADC (150) is a RF band-pass sub-sampled sigma-delta analog to digital converter. The present invention also provides a MR imaging system (110) comprising such a RF antenna device (140). This provides an integration of the RF coil and the components into the RF antenna device, which are required to provide the MR information signal as a digital signal. The digital MR information signal can easily be further processed and transmitted, even in the presence of strong magnetic and RF fields. Sigma-delta modulators have a relatively low cost, a high robustness, and power consumption and dynamic range can easily be exchanged and enable high resolution and high linearity for low power in the signal band of interest in an efficient way. The solution enables an increased integration level, avoids the usage of expensive RF cables and increases the robustness of the overall signal acquisition and propagation. Sub sampling means that the sigma-delta analog to digital converter has a sampling frequency which is below the Nyquist frequency of a RF carrier signal within the analog MR information signal.
