The dead time of RF receiver systems is a long standing problem in pulsed NMR and EPR. After the high power TX RF pulse has been applied, the receiver is overloaded for a time Td=30*Q/w, where Q is the loaded quality factor and R is the resonant frequency. Over the years to minimise Td several solutions have been proposed [l-2]. Recently, a cross-coil design with single TX RF coil and double-channel out-of-phase receiver, was introduced for 220 MHz EPR [3-41. It was experimentally shown that, with a careful tuning/matching of the RF coils, the isolation between TX and RX could be increased from -20 dB (single RX) to -55 dB (double RX) [3-41.

Theoretical and Experimental Optimisation of the Dead time of RF Coils

ALECCI, MARCELLO;PLACIDI, GIUSEPPE;
2000-01-01

Abstract

The dead time of RF receiver systems is a long standing problem in pulsed NMR and EPR. After the high power TX RF pulse has been applied, the receiver is overloaded for a time Td=30*Q/w, where Q is the loaded quality factor and R is the resonant frequency. Over the years to minimise Td several solutions have been proposed [l-2]. Recently, a cross-coil design with single TX RF coil and double-channel out-of-phase receiver, was introduced for 220 MHz EPR [3-41. It was experimentally shown that, with a careful tuning/matching of the RF coils, the isolation between TX and RX could be increased from -20 dB (single RX) to -55 dB (double RX) [3-41.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11697/43971
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