vhf Pulsed Magnetic Resonance Duplexers

Coupling schemes for pulsed magnetic resonance spectrometers operating in the vhf region are discussed. Three such schemes are described in detail and their performances compared, using the 81Br nuclear quadrupole resonance signal at ∼200 MHz in polycrystalline K2PtBr6. The first scheme employs a hybrid T, coaxial ring circuit with the transmitter, receiver, sample coil, and a dummy load in the four arms. Series and shunt PIN diode switching elements form the basis of the second scheme proposed. Finally, a PIN diode bridge which combines the previous two schemes is described.