  Detection of electron paramagnetic resonance (EPR) using a microwave cavity
resonating at a fixed frequency (between 9 and 10 GHz) remains the most popular
method until now. Here, we report a cavity-less technique which makes use of
only an impedance analyzer and a copper strip coil to detect L-band EPR (f =
1-3 GHz) in the standard EPR marker 2,2-diphenyl-1-picrylhydrazyl (DPPH). Our
method relies on measuring the magnetoimpedance (MI) response of DPPH through a
copper strip coil that encloses DPPH. In contrast to commercial EPR which
measures only the field derivative of power absorption, our method enables us
to deduce both absorption and dispersion. Changes in resistance (R) and
reactance (X) of the copper strip while sweeping an external dc magnetic field,
were measured for different frequencies (f = 0.9 to 2.5 GHz) of radio-frequency
current in the coil. R exhibits a sharp peak at a critical value of the dc
magnetic field, which is identified as the resonance field and X shows a
dispersion at the same frequency. The data were analyzed to obtain line width
and resonance field parameters. The resonance field increased linearly with
frequency and the obtained Land\'e g factor of 1.999 is close to the accepted
value of 2.0036, measured in X-band. The simplicity of this technique can be
exploited to study paramagnetic centers in catalysis and other materials.
