A 1-2 GHZ PULSED AND CONTINUOUS-WAVE ELECTRON-PARAMAGNETIC-RESONANCE SPECTROMETER

A microwave bridge has been constructed that performs three types of e lectron paramagnetic resonance experiments: continuous wave, pulsed sa turation recovery, and pulsed electron spin echo. Switching between ex periment types can be accomplished via front-panel switches without mo ving the sample. Design features and performance of the bridge and of a resonator used in testing the bridge are described. The bridge is co nstructed of coaxial components connected with semirigid cable. Partic ular attention has been paid to low-noise design of the preamplifier a nd stability of automatic frequency control circuits. The bridge incor porates a Smith chart display and phase adjustment meter for ease of t uning. (C) 1996 American Institute of Physics.