Observation of compounds with very short signal life times by methods such as ultra-short echo time (UTE) [1], Zero Echo Time (ZTE) [2] or Swept Imaging with Fourier Transform (SWIFT) [3] prompts for Transmit-Receive (T/R) switches with settling times of the order of 1 µs. Since clinical MRI systems typically provide transient times which are at least an order of magnitude longer, custom units need to be deployed and integrated into the scanner’s radio frequency (RF) front-end, which poses some questions about control and system protection. Here we present a novel 8-channel unit of T/R switches with symmetric biasing [4] comprising optical trigger lines, malfunction surveillance and a novel bias driver circuitry for this purpose.For T/R array applications, a box able to house 8 T/R switches for 7 T, preamplification, bias drivers, malfunction detection and fibre-optical triggering was constructed (Fig. 1a&d). Each T/R switch unit is built in a symmetrically biased PIN diode architecture (Fig. 1b, [4]) enabling fast switching while producing a very low spike/video leakage due to its inherent cancellation of the diode biasing signal on the RF signal lines. For diode biasing, common-mode chokes are deployed. Compared with bias inductor chokes the low-pass filtering of the control signal flank is thereby avoided since the common-mode chokes provide a low impedance for the differentially routed biasing signal but nevertheless choke the RF signals by their high inductance presented to the RF signals which run as common-mode to the choke. Furthermore, a novel differential, high peak current (2 A) diode driver was developed (Fig. 1c). Fast settling and low common-mode levels of the bias voltages are achieved by an active feed-back regulation. For monitoring fail states, the reverse voltages and the forward currents are monitored in real-time and an assertion signal confirming the proper settling of the units in the demanded state is generated. In order to prevent interferences on the high speed trigger and assertion lines these signals are routed in an optical fibre. A unit installed outside the Faraday cage provides the required supply voltages and trigger interfaces for standard voltage levels.The switch offers a 10-99% signal rise time of 350 ns with a total video leakage of 20 mVpp and an in-band noise transient of -89 dBm (Fig. 2a) such that clean acquisitions 1 µs after the RF pulse are demonstrated. The RF signal characteristics are collected in Fig. 2b. The performance of the unit is demonstrated in a ZTE experiment with 500 kHz total bandwidth and the background signal artefact level is assessed (Fig. 2c) with a standard volume resonator (Noval Medical, Wilmington, USA) and with a custom, proton free loop coil (e). This proved to be a very sensitive indicator for remnant signal modulations or cracklings after throwing the switch. This is shown in (Fig. 2d) which was acquired with the same setup except using a T/R switch in a traditional design providing ~1 µs signal rise times. Further, an in-vivo image of healthy human subject was acquired (Fig. 2f). The measurements were performed on a human 7 T scanner (Philips Healthcare, Best, Netherlands) and the RF signals were acquired with a high-bandwidth spectrometer (Skope MRT, Zurich, Switzerland).The novel, symmetrically biased, high power T/R switch RF frontend enables acquisitions with total dead time after an excitation pulse of about 1 µs such that echo times and k-space gaps in ZTE scans become dominated by the duration of the RF pulse itself, even for very small flip angles. The optical triggering and system monitoring provide facile means to integrate the unit into the scanner environment. It is exemplified that ZTE scans under the full available gradient strength and a bandwidth of 500 kHz are obtained with very low artefact levels. The applied PIN diode biasing topology can analogously be implemented for active detuning of receive and transmit only coils since the applied tank circuits are topologically equivalent to the deployed isolation stages in the switch.